JP2002338069A - Paper feeding device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable use of a large-sized paper with a simple and low-cost structure in a tandem type paper feeding device. SOLUTION: A second paper feeding tray 3a is fixed, and only a first paper feeding tray 11 is elevated up and down by an elevation driving means 12. When a large-sized paper is to be used, a U-shaped auxiliary tray 72 is drawn almost horizontally from the first paper feeding tray 11, and about the left half of the paper is supported by this auxiliary tray 72. Openings 3b and 3b allowing vertical passage of the auxiliary tray 72 are formed on the second paper feeding tray 3a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tandem type paper feeder in which two paper feed trays are provided substantially horizontally and in parallel, a printing machine having the paper feeder, a copier, a facsimile, a printer and the like. The present invention relates to an image forming apparatus.

[0002]

2. Description of the Related Art In a tandem type paper feeder, for example, as described in JP-A-11-240630,
Two paper feed trays are provided substantially horizontally and side by side, and each paper feed tray can be raised and lowered by separate lifting drive means. Paper supply means for separating and feeding paper one by one corresponding to one of the two paper supply trays is provided, and as the number of papers decreases, the paper supply tray rises, and is fixed. Paper feeding pressure. When the paper in the paper feed tray runs out, the paper stacked in the other paper feed tray is pressed and transferred substantially horizontally to change the paper so that paper feeding is continued. As a result, a large amount of paper can be fed. In such a tandem-type sheet feeding device, large-sized sheets over two sheet feeding trays may be stacked and fed. In this case, for example, the left tray is raised while keeping it substantially horizontal in conjunction with the raising operation of the right tray.

[0003]

As described above, conventionally, two paper feed trays are configured to be moved up and down by separate lifting and lowering driving means.
It is necessary one by one, and an increase in the size and complexity of the configuration cannot be avoided. Further, there is a problem that the frequency of failure increases due to the complicated configuration and the plurality of driving sources, and the maintenance cost also increases.

Accordingly, the present invention provides a tandem-type paper feeder which can solve the above-described problem in loading large-size paper.
It is an object of the present invention to provide an image forming apparatus having the sheet feeding device.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, a first paper feed tray capable of stacking and storing a plurality of papers and capable of moving up and down, and a first paper supply tray are provided. Elevating drive means for elevating and lowering the paper tray, paper feeding means for feeding sheets one by one from the first paper tray, and a plurality of sheets capable of being stacked and accommodated in parallel with the first paper tray The first sheet feeder feeds the sheets stacked on the second sheet feed tray in a state where the second sheet feed tray fixedly provided, the first sheet feed tray and the second sheet feed tray are substantially horizontal. A sheet transfer means for transferring the sheet to the tray, and an auxiliary tray which is provided so as to be able to protrude and retract from the first sheet supply tray and extends to a sheet stacking area of the second sheet supply tray while projecting from the first sheet supply tray. Is adopted.

According to a second aspect of the present invention, in the paper feeder of the first aspect, the auxiliary tray is configured to be pulled out substantially horizontally to the second paper feed tray side.

According to a third aspect of the present invention, in the paper feeder of the second aspect, an opening is formed in the second paper feed tray to allow the drawn-out auxiliary tray to pass vertically. It has a configuration.

[0008] According to the invention described in claim 4, in claim 2 or 3
In the paper feeding device described above, a configuration is adopted in which when the auxiliary tray is pulled out, there is a click feeling for distinguishing the paper size due to engagement with the first paper feeding tray.

According to the fifth aspect of the present invention, the second or third aspect is provided.
In the above-described paper feeder, a configuration is adopted in which a drawer amount detection unit that detects a drawer amount of the auxiliary tray is provided.

According to a sixth aspect of the present invention, in the paper feeder according to the fifth aspect, the position of the sheet transfer means is automatically adjusted as an end fence in accordance with the amount of withdrawal detected by the withdrawal amount detection means. It changes the position.

According to the seventh aspect of the present invention, the first to sixth aspects are provided.
A sheet detecting means for detecting the presence or absence of a sheet between the first sheet feeding tray and the second sheet feeding tray; In the case where small-sized sheets are individually loaded on the second sheet feeding tray, if the sheet detecting means detects that there is a sheet, it is determined that the sheet is set abnormally, and the first sheet feeding tray is set using the auxiliary tray. When large-size sheets are stacked and detected by the sheet detection means, setting of the sheet size change information does not cause a setting error.

According to an eighth aspect of the present invention, in the paper feeder according to the seventh aspect, there is provided means for detecting a use state of the auxiliary tray, and when the auxiliary tray is not in a use state, the apparatus is adapted to print on a large-size sheet. A warning is issued when paper size change information is input.

According to the ninth aspect of the present invention, the first to eighth aspects are provided.
In the sheet feeding device according to any one of the above, when the auxiliary tray is used, the amount of sheets stacked on the first sheet feeding tray is limited.

According to a tenth aspect of the present invention, in the paper feeder of the ninth aspect, the paper stacking amount is limited by setting a lower limit position of the first paper feed tray upward. Has been adopted.

According to an eleventh aspect of the present invention, in the paper feeder according to the ninth or tenth aspect, the configuration is such that the paper stacking limit on the first paper feed tray is changed in accordance with the pull-out amount of the auxiliary tray. I am taking it.

According to a twelfth aspect of the present invention, in the paper feeder according to the first aspect, the auxiliary tray is configured to be rotated in a vertical direction and fall down substantially horizontally.

According to a thirteenth aspect of the present invention, in the paper feeder of the first aspect, the auxiliary tray is configured to be pulled out by being rotated substantially horizontally.

According to a fourteenth aspect of the present invention, in the paper feeder of the twelfth or thirteenth aspect, there is provided a paper detecting means for detecting the presence or absence of a paper between the first paper feed tray and the second paper feed tray. When small-size sheets are individually stacked on the first sheet tray and the second sheet tray, when the sheet detecting means detects that there is a sheet, it is determined that the sheet is set abnormally, and the auxiliary tray is set. When a large-size sheet is stacked on the first sheet feed tray and is detected by the sheet detecting means, setting of the sheet size change information does not cause a setting error. I have.

According to a fifteenth aspect of the present invention, in the paper feeder according to the fourteenth aspect, there is provided means for detecting a use state of the auxiliary tray, and when the auxiliary tray is not in the use state, the apparatus is capable of processing large-size paper. A warning is issued when paper size change information is input.

According to a sixteenth aspect of the present invention, in the paper feeding apparatus according to any one of the twelfth to fifteenth aspects, the amount of paper loaded on the first paper feeding tray is limited when the auxiliary tray is used. The configuration is adopted.

According to a seventeenth aspect of the present invention, in the paper feeder according to the sixteenth aspect, the paper loading amount is limited.
This is achieved by setting the lower limit position of the first paper feed tray upward.

According to an eighteenth aspect of the present invention, in the paper feeding device according to any one of the first to seventeenth aspects, when the auxiliary tray is used, loading of sheets on the second paper feeding tray is prohibited. The configuration is adopted.

According to a nineteenth aspect of the present invention, in the paper feeder according to any one of the first to seventeenth aspects, when paper is present in the second paper feed tray, use of the auxiliary tray is prohibited. , Is adopted.

According to a twentieth aspect of the present invention, in the paper feeder according to any one of the first to nineteenth aspects, the first paper feed tray can be manually raised and lowered.

According to a twenty-first aspect of the present invention, in the paper feeder according to any one of the first to twentieth aspects, at least the first paper feed tray, the lifting / lowering driving means, and the second paper feed tray are provided. Is integrated as a detachable unit with respect to the apparatus main body, and the first paper feed tray is provided so as not to automatically lower when the unit is pulled out from the apparatus main body.

According to a twenty-second aspect of the present invention, in the image forming apparatus for forming an image on a sheet fed one by one from a sheet feeding device, the sheet feeding device is one of the first to twenty-first aspects. It is a configuration that it is.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. First, the configuration of a stencil printing machine 30 as an image forming apparatus according to the present embodiment and an outline of a printing operation will be described with reference to FIG. The stencil printing machine 30 includes an image forming unit 34 provided at a substantially central portion of the apparatus main body 32, a tandem-type sheet feeding device 2 provided below the image forming unit 34, and an image forming unit 34 An optical reading section 38 as an original reading section is provided. The image forming unit 34 includes a printing unit 40, a plate making unit 42,
It has a plate discharging section 44 and the like. The printing unit 40 includes a printing drum 48 having an ink supply unit 46 therein and a press roller 50 provided to be able to freely contact and separate from the printing drum 48.
Etc. The ink supply means 46 includes the printing drum 4.
An ink supply pipe 52 also serving as a rotation shaft 8, an ink roller 54, and a doctor roller 56 are provided. The ink supplied from the ink supply pipe 52 is dropped into a wedge-shaped ink reservoir between the ink roller 54 and the doctor roller 56, and the ink in the ink reservoir is supplied to the ink roller 54 while the layer thickness is regulated by the doctor roller 56. The ink supplied to the ink roller 54 is supplied to the inner peripheral surface of the printing drum 48.

When a plate making start key (not shown) is depressed, the reading operation of the original image is started in the optical reading section 38 and the printing drum 4 is
The peeling operation of the used master (not shown) on 8 is performed. In the plate making section 42, a thermal head (not shown) is driven based on image information from the optical reading section 38, and perforating and making a master (not shown). The master made is a clamper 58 provided on the outer peripheral surface of the printing drum 48.
The printing drum 48 is wound around the outer peripheral surface of the printing drum 48 as the printing drum 48 rotates.

The paper (printing paper) separated and fed one by one from the paper feeding device 2 is sent to the registration roller pair 62 by the conveyance roller pairs 9 and 60. The paper is temporarily stopped by the pair of registration rollers 62, and after correcting the oblique displacement,
At the timing when the leading edge of the image on the print drum 48 coincides with the predetermined position in the sheet transport direction, the image is sent to the print portion by the registration roller pair 62. The press roller 50 moves up in synchronization with the feed timing of the registration roller pair 62, and the sheet is pressed against the print drum 48. By this pressing operation, the ink supplied to the inner peripheral surface of the printing drum 48 oozes through an opening (not shown) of the printing drum 48 and a perforated portion of the master, and is transferred onto the paper. The paper on which the ink image has been formed is separated from the outer peripheral surface of the printing drum 48 by the separation claw 64, conveyed by paper discharge conveyance means 66 of a type that suctions and adsorbs on the belt by air pressure, and discharged to the paper discharge tray 68. .

Next, the configuration and functions of the tandem type sheet feeding device 2 will be described in detail. As shown in FIG. 11, a sheet feeding frame 3 having a step is housed in the sheet feeding device 2 detachably in a sheet width direction orthogonal to the sheet feeding direction with respect to the sheet feeding device main body. In the paper feed frame 3, a first paper storage unit 4 and a second paper storage unit 5 that store a plurality of small-sized paper sheets of the same size (for example, A4) in the same direction are formed in parallel with a step portion as a boundary. I have. The first paper storage unit 4 is provided with a first paper feed tray 11 that can move up and down.
The bottom surface 3a of the second paper storage unit 5 is a fixed second paper feed tray. The first paper feed tray 11 and the second paper feed tray 3a are provided substantially horizontally and in parallel. The first paper feed tray 11 has a number of reinforcing ribs inside,
It is integrally molded with synthetic resin. First paper feed tray 11
Is driven up and down by a lifting drive unit 12. The elevating drive unit 12 includes a drive motor 12 a and an elevating mechanism (not shown).
When the sheet feeding unit in which the sheet feeding unit and the like are integrally assembled is set in the sheet feeding device main body, the first sheet feeding tray 11 is connected to the elevating mechanism so as to be able to move up and down.

The small-sized paper P1 stored in the first paper storage unit 4, that is, loaded on the first paper feed tray 11,
Above the front end side (upper right side) of A, a paper feeding means 70 for feeding out the paper P1A is provided. The paper feeding unit 70 includes a pickup roller 6 that contacts the upper surface of the sheet P1A, a feed roller 7 that separates the sheet P1A drawn by the pickup roller 6 into one sheet, and a reverse roller 8.
have. Although not shown, the sheet P1 stacked on the first sheet tray 11 is
A paper end detection sensor for detecting the presence or absence of A is provided. The sheet P1A separated into one sheet is sent to the image forming unit 34 by the conveying roller pair 9, and undergoes the above-described image forming process.

In the first sheet storage section 4 of the sheet feeding frame 3,
A pair of side fences 10, which align the side edges of the paper P1A,
The first paper feed tray 11 has insertion holes 11 a for the side fence 10. The side fence 10 can be moved in the sheet width direction orthogonal to the sheet feeding direction according to the sheet size, and the insertion holes 11a, 11a are formed in a size that allows the side fence 10 to move. I have. One side fence 10 is provided with a sensor 20 for detecting the remaining amount of the sheet P1A. First paper feed tray 11
Is raised and lowered while being guided by a guide member (not shown). Inside the first paper feed tray 11,
A substantially U-shaped auxiliary tray 72 used for stacking large-sized sheets is accommodated so as to be able to protrude and retract. The auxiliary tray 72 will be described later in detail.

The second sheet feed tray 3a is provided with a pair of side fences 13, 13 for aligning the side edges of the sheet P1B.
There is provided a sensor 15 for detecting the remaining amount of the battery. Also,
The second tray 3a has an auxiliary tray 7
Openings 3b, 3b are formed to allow the up and down (up and down) passage of the second 2. The second paper feed tray 3a has an end fence 14 as a sheet transfer unit for transferring the stacked sheets P1B collectively to the first sheet storage unit 4, and a drive (not shown) for driving the end fence 14. Means are provided. On the lower surface of the second paper feed tray 3a, a paper presence / absence detection sensor 16 for detecting the presence / absence of the paper P1B on the second paper feed tray 3a is provided. Projecting above the loading surface. Also, the first
A sheet detecting means 18 for detecting the presence or absence of a sheet is provided between the sheet feeding tray 11 and the second sheet feeding tray 3a.

As shown in FIG. 12, the pickup roller 6 is held by an arm 74 whose one end is rotatably supported by the rotation shaft of the feed roller 7, and is urged downward by a spring (not shown). I have. When the paper feeding unit is set in the paper feeding device main body, the paper feeding unit is lowered to a lowermost position indicated by a two-dot chain line by the urging force of the spring. Conversely, when the paper feeding unit is pulled out of the paper feeding device main body, it is positioned at the uppermost position shown by the two-dot chain line against the spring pressure so as not to interfere with the paper P1A or the first paper feeding tray 11. It has become. At the time of paper feed standby, the paper P1A stacked on the first paper feed tray 11 is lifted by the first paper feed tray 11 so that the uppermost paper P1A is held at a predetermined height. At this time, as shown by the solid line, the pickup roller 6 moves the sheet P1A from the lowest position.
, And comes in contact with the sheet P1A with a desired pressure (feed pressure).

As shown in FIG.
Has a paper detection lever 18a rotatably supported on the side fence 13 in a horizontal plane, and a photo sensor 18b turned on and off by the paper detection lever 18a. The paper detection lever 18a is always turned on by a spring (not shown). It protrudes toward the paper loading area. FIG.
(A) shows a state in which the sheets P1A and P1B are normally set. In this state, the sheets P1A and P1B are set.
There is a space between them, and the paper detection lever 18a does not rotate, so that the photo sensor 18b maintains the OFF state. If any one of the sheets P1A and P1B is not set normally, for example, if the sheet P1B is shifted toward the first sheet storage unit 4, the sheet detection lever 18a is retracted as shown in FIG. I do. As a result, the photo sensor 18b turns ON. When an ON signal of the photo sensor 18b is received, a control unit (not shown) controls the stencil printing machine 30 through a display unit such as a liquid crystal display unit of an operation panel (not shown).
A set error is displayed.

When the paper end detecting sensor provided near the pickup roller 6 detects that all the sheets P1A stacked on the first sheet feeding tray 11 have been fed and has been lost, FIG. As shown in (1), the first paper feed tray 11 descends toward the lower limit position. The lower limit position here is, as shown in FIG.
1 is a position where the loading surface is slightly lower than the second paper feed tray 3a. In other words, when the paper P1B loaded on the second paper feed tray 3a is transported to the first paper feed tray 11, the paper P1B moves smoothly at the boundary portion, and no deviation occurs due to a step. Position. When it is determined based on the detection information of the paper presence / absence detection sensor 16 that the paper P1B is present on the second paper feed tray 3a, the control means moves the end fence 14 to the first paper feed tray 11 side. By the movement of the end fence 14, the paper P1B is transported onto the first paper feed tray 11. End fence 1
When the sheet 4 moves, the sheet detecting lever 18a of the sheet detecting means 18 is retracted outside the sheet conveying path by an actuator (not shown).

After the transfer of the sheet P1B by the end fence 14 is completed, the uppermost sheet P1B is held at a predetermined height in the same manner as when the sheet P1A is stacked on the first sheet feeding tray 11. To rise. The pickup roller 6 comes into contact with the uppermost sheet P1B with a predetermined pressure, and enters a sheet feeding standby state. The end fence 14 is returned to the home position on the left side of the second sheet storage unit 5. As shown in FIG. 16, when there is no paper in the second paper storage unit 5, the end fence 14 does not operate, and the control unit displays the absence of paper via a display unit such as a liquid crystal display unit of an operation panel. .
In response to this display, a relatively small size sheet, for example, an A4 size sheet is set in the first sheet storage section 4 and / or the second sheet storage section 5. The sheet feeding operation after the setting is as described above.

The above is the original use of the tandem type. The use of stacking large-size sheets over the first sheet storage section 4 and the second sheet storage section 5 will be described below. FIG. 1 shows a case where the auxiliary tray 72 is pulled out from the first paper feed tray 11 and large-sized paper, for example, A3-sized paper P2 is stacked. As shown in FIG.
The auxiliary tray 72 is pulled out at the lower limit position of the first paper feed tray 11, and extends in a state where the lower surface of the second paper feed tray 3a overlaps the loading area of the second paper feed tray 3a. In this state, even if the paper P2 is stacked on the first paper feed tray 11, the substantially left half of the paper P2 is not placed on the auxiliary tray 72, but is loaded on the second paper feed tray 3a. When the large-sized sheet P2 is set, after the setting, the sheet size change information is input through an operation panel or the like. Paper P2
When the first paper storage unit 4 and the second paper storage unit 5 are set
, The paper detection means 18 detects the presence of paper, but when paper size change information is input, the control means does not determine that there is a setting error.

As shown in FIG. 2, the first paper feed tray 11
Rises so that the uppermost sheet P2 is held at a predetermined height. Since the auxiliary tray 72 passes through the openings 3b, 3b of the second sheet feeding tray 3a, the second sheet feeding tray 3a
Is lifted up by being supported by the auxiliary tray 72. That is, the auxiliary tray 72 functions as an extension of the first paper feed tray 11. The paper feeding operation is the same as that for the small-sized paper described above.

As shown in FIG. 3, the auxiliary tray 72 has a guide rail 11 as a rectangular hole of the first sheet feeding tray 11.
b is provided so as to slide, and is pulled out substantially horizontally by the operator's hand. FIG. 4 is a plan view showing a state in which the auxiliary tray 72 is accommodated in the first paper feed tray 11. In the present embodiment, as shown in FIG. 5, when the auxiliary tray 72 is pulled out of the auxiliary tray 72, the first paper feed tray 11 can be sensibly distinguished.
Is configured so that there is a click feeling due to the engagement between. That is, the side surface 11c of the guide rail 11b
The auxiliary tray 72 is integrally formed with a convex portion 11d that can be elastically deformed, and a plurality of concave portions 72a with which the convex portions 11d are engaged are formed on the corresponding side surface of the auxiliary tray 72 in accordance with the standard size of paper.

When the auxiliary tray 72 is pulled out from the state where it is completely accommodated in the first paper feed tray 11, first the LTT
The convex portion 11d elastically engages with the concave portion 72a corresponding to the size, and a click feeling (a snap engaging feeling) is generated. The operator recognizes from this click feeling that the amount of withdrawal corresponds to the paper size of LTT, and if the size of the paper to be loaded is LTT, stop the drawer when the first click feeling occurs. In this case, the auxiliary tray 72 has an appropriate amount to be pulled out for LTT-size sheets. The same applies to the sizes of A4T, LG, B4, and A3. If the withdrawal amount is zero, the loading target is A4
It becomes Y size. The same click feeling can be obtained even if the convex portion 11d and the concave portion 72a are formed in the reverse mode.

Further, as shown in FIG.
On the opposite side, a multi-rotation resistance type withdrawal amount detecting means 76 for detecting the withdrawal amount of the auxiliary tray 72 is provided (omitted in FIG. 5), and the detected resistance value is output to the control means. The relational data between the resistance value and the paper size is stored in advance in the ROM of the control means, and the control means determines the amount of paper drawn out of the auxiliary tray 72 based on the output resistance value V, as shown in FIG. Convert to size. When the paper size is detected, the control means moves the end fence 14 located at the home position to an appropriate position corresponding to the determined paper size, that is, the size of the stacked paper. The proper position is a position where an end fence function capable of preventing a positional deviation in the sheet feeding direction can be obtained. Or, conversely, the end fence 14 may be moved to an appropriate position based on the paper size change information. The detection of the amount of paper drawn out of the auxiliary tray 72 or the paper size corresponding to the amount of paper drawn out may be performed by separately providing a sensor in the first paper supply tray 11 or provided in the first paper supply tray 11. One sensor may be used to read the mark at the fixed size position on the auxiliary tray 72. Although the input of the paper size change information is performed after the large-sized paper is stacked, the input of the paper size change information may be automatically input based on the detection of the withdrawal amount detecting means 76 or the like. In this case, there is an advantage that it is not necessary to input the paper size change information.

The capacity of the drive motor 12a of the elevation drive means 12 is set only when small-size sheets are stacked on the first sheet supply tray 11. As described above, since the second paper feed tray 3a is fixed and does not rise in accordance with the first paper feed tray 11, for example, when loading A3 size paper, it is equivalent to A4 size paper. When a number of sheets are stacked, the weight is doubled and exceeds the load torque of the drive motor 12a. of course,
A large-torque motor that can drive a large-sized sheet full of paper may be used. In this embodiment, in order to use the drive motor 12a as it is, that is, to make the load torque of the drive motor 12a substantially constant, the amount of paper loaded on the first paper feed tray 11 when the auxiliary tray 72 is used is limited. I am trying to do it.

Specifically, the lower limit position of the first paper feed tray 11 is set upward. FIG. 8 shows a case in which sheets of A3 size are stacked. In this case, the lower limit position DL1 is a substantially middle position of the vertical stroke of the first sheet feeding tray 11, and only about half the number of sheets of A4 size is stacked. It is a position that cannot be done. FIG. 9 shows a case where B4 size sheets are stacked. In this case, the lower limit position DL2 is a position where only about 1.3 times as many sheets as A3 size sheets can be stacked.
That is, the paper stack limit amount on the first paper feed tray 11 is changed in accordance with the pull-out amount of the auxiliary tray 72. These lower limit positions may be detected by individually providing sensors, or may be returned to the lowermost position (the lower limit position corresponding to A4 size paper) and then positioned by managing the number of steps of the drive motor 12a. Good.

First paper feed tray 1 when loading large-size paper
The lower limit position setting of 1 is automatically performed by the control means.
In this case, the withdrawal amount detection means 76 and the like function as means for detecting the use state of the auxiliary tray, and when the withdrawal amount detection means 76 and the like operate, the control means determines that the auxiliary tray 72 has been withdrawn, and The first paper feed tray 11 is moved to a predetermined lower limit position based on the detected paper size. When stacking large-sized sheets without providing a plurality of lower limit positions of the first sheet feeding tray 11, the amount of the smaller-sized sheets is smaller than the stacked amount of small-sized sheets via a display unit such as a liquid crystal display unit of an operation panel. (For example, half) may be displayed to be loaded to maintain the capacity of the drive motor 12a. Further, when the paper size change information is input to the large-sized paper when the auxiliary tray 72 is not in use, the control unit issues a warning via a display unit such as a liquid crystal display unit of the operation panel. It may be.

In this embodiment, the use of the auxiliary tray 72 is prohibited when paper is present in the second paper feed tray 3a. When there is no paper in the first paper tray 11 and small-sized paper is loaded in the second paper storage unit 5 in a state where the auxiliary tray 72 is pulled out, if the first paper tray 11 rises, An overload on the drive motor 12a is concerned. Since the auxiliary tray 72 in the present embodiment is configured to be pulled out substantially horizontally as described above, when sheets are stacked and present on the second sheet feed tray 3a, the sheets must be drawn out in order to interfere with the sheets. become unable. However, even when paper is present in the second paper feed tray 3a,
When the first paper feed tray 11 is not at the lowermost position and the draw-out position of the auxiliary tray 72 is higher than the upper surface of the sheet, the draw-out of the auxiliary tray 72 is possible. For this reason, when there is no paper in the first paper feed tray 11 and there is paper in the second paper feed tray 3 a in a state where the auxiliary tray 72 is pulled out, the control means operates the elevation drive means 12. Instead, the necessity of paper resetting is displayed via a display means such as a liquid crystal display unit of the operation panel. Second paper feed tray 3a
If there is a sheet, a warning that "the auxiliary tray cannot be used" may be issued. In addition, a procedure for setting a paper size using an operation panel or the like before stacking large-sized paper is performed. , "The auxiliary tray cannot be used."
A warning to that effect may be issued.

When the auxiliary tray 72 is used, the second
The stacking of small-size sheets on the sheet feed tray 3a may be prohibited. In this case, the same concern as above may be considered. Therefore, when the use of the auxiliary tray 72 is detected by the withdrawal amount detecting means 76 or the like, for example, the second operation is performed via a display means such as a liquid crystal display section of the operation panel. Paper cannot be loaded in the paper tray. " Depending on the configuration and mounting method of the auxiliary tray 72, the first tray may be used as described above.
Since it is expected that the first paper feed tray 11 cannot be pulled out at the lowermost position, the first paper feed tray 11 can be manually moved up and down, and the auxiliary tray 72 can be pulled out at an arbitrary position. If the first paper feed tray 11 automatically lowers when the paper feed unit is pulled out of the paper feeder main body, the drawn out auxiliary tray 72 interferes with the paper and other members and is damaged. Therefore, for example, a switch that operates in conjunction with the pull-out operation may be provided, and the elevation drive unit 12 may not be operated by the switch.

When using a small-sized paper (for example, A3) after using a large-sized paper (for example, A3), the auxiliary tray 72 is stored in the first paper feed tray 11, and then an operation panel or the like is used. , The user inputs paper size change information.

In the above embodiment, the auxiliary tray 72 is pulled out substantially horizontally. However, as shown in FIG.
The auxiliary tray 78 may be a gate-shaped auxiliary tray 78 that is rotated in the vertical direction around the center and tilted substantially horizontally, as shown in FIG.
Tray 8 that is pulled out by rotating it approximately horizontally around the center
It may be set to 0. The same functions as those of the above-described embodiment can be obtained in these auxiliary trays 78 and 80, and the same settings except for the drawer can be performed. In the above embodiments, the auxiliary tray 72 is manually pulled out from the viewpoint of simplification of the configuration and cost reduction. However, the use state is automatically set based on the paper size information set by the operation panel or the like. You may.

[0050]

According to the first or second aspect of the present invention,
A first paper feed tray capable of stacking and storing a plurality of papers and capable of moving up and down, an elevating drive unit for raising and lowering the first paper feed tray, and feeding papers one by one from the first paper feed tray Paper feeding means, a second paper feeding tray capable of stacking and storing a plurality of papers, and provided in parallel with the first paper feeding tray;
Sheet transfer means for transferring sheets stacked on the second sheet supply tray to the first sheet supply tray while the first sheet supply tray and the second sheet supply tray are substantially horizontal; The second tray is provided so as to be able to protrude and retract from the first paper feed tray.
And the auxiliary tray extending to the sheet stacking area of the sheet feeding tray of the first embodiment can eliminate the need for the drive means for raising and lowering the second sheet feeding tray, thereby reducing the size and weight of the apparatus and the associated cost. , Simplification of control, simplification of maintenance, and cost reduction can be realized.

According to the second or twenty-second aspect of the present invention, since the auxiliary tray is configured to be pulled out substantially horizontally to the second paper feed tray side, it is possible to obtain a configuration for a large-sized paper in a small space. .

According to the third or 22nd aspect of the present invention, the second paper feed tray is formed with an opening that allows the pulled-out auxiliary tray to pass up and down. The auxiliary tray can be pulled out even at the lowermost position of the paper tray.

According to the invention described in claim 4 or 22, when the auxiliary tray is pulled out, there is a click feeling for distinguishing the paper size by engagement with the first paper feed tray. In addition, it is possible to easily obtain an appropriate amount of drawing-out for the paper size by manual operation.

According to the fifth or 22nd aspect of the present invention, since there is provided a drawer amount detecting means for detecting the drawer amount of the auxiliary tray, it is possible to automate paper size determination and the like.

According to the present invention, the position of the sheet transfer means is automatically changed to a proper position as the end fence in accordance with the amount of withdrawal detected by the withdrawal amount detecting means. The misalignment of the stacked sheets can be prevented.

According to the present invention, the first sheet feed tray has a sheet detecting means for detecting the presence or absence of a sheet between the first sheet feed tray and the second sheet feed tray. And the second
When small-size paper is individually loaded on the paper feed tray, the paper detection unit detects that paper is present, and determines that the paper is set abnormally. When the paper size change information is input when the paper is stacked and detected by the paper detection means, the setting is not abnormal, so that the setting failure of the small-sized paper can be quickly detected. Thus, a large-size sheet stacking configuration can be formed.

According to the invention of claim 8 or 22, there is provided means for detecting the use state of the auxiliary tray, and when the auxiliary tray is not in use, the input of the paper size change information for the large-sized paper is performed. Since a warning is issued in the event that this is done, it is possible to prevent large-size sheets from being loaded without the auxiliary tray being used.

According to the ninth or twenty-second aspect of the present invention, when the auxiliary tray is used, the amount of paper loaded on the first paper feed tray is limited, so that the drive source for small-sized paper can be used as it is. In addition, it is possible to prevent an increase in cost due to providing a driving source having a large capacity.

According to the invention of claim 10 or 22,
Since the sheet stacking amount is limited by setting the lower limit position of the first sheet feeding tray upward, the sheet stacking amount can be reliably limited with a simple configuration.

According to the invention of claim 11 or 22,
Since the limit on the amount of paper to be loaded on the first paper feed tray is changed in accordance with the amount of pull-out of the auxiliary tray, it is possible to reliably prevent an overload of the lifting drive means.

According to the invention of claim 12 or 22,
Since the auxiliary tray has a configuration in which the auxiliary tray is rotated in the vertical direction and tilted substantially horizontally, it is possible to form a large-size sheet stacking configuration with a simple configuration.

According to the invention of claim 13 or 22,
Since the auxiliary tray is configured to be rotated substantially horizontally and pulled out, a large-sized sheet stacking configuration can be formed with a simple configuration.

According to the invention of claim 14 or 22,
There is a sheet detecting means for detecting the presence or absence of a sheet between the first sheet tray and the second sheet tray, and small-sized sheets are individually placed in the first sheet tray and the second sheet tray. When the paper detecting unit detects that there is a sheet in the stacking state, it is determined that the sheet is set abnormally, and a large-sized sheet is stacked on the first sheet feeding tray using the auxiliary tray and detected by the sheet detecting unit. When the paper size change information is entered, the setting does not cause a setting error.
A stacking configuration of large-size sheets can be formed in a state where a setting failure of small-size sheets can be quickly detected.

According to the invention of claim 15 or 22,
The auxiliary tray has a means for detecting the use state of the auxiliary tray, and a warning is issued when paper size change information for large-sized paper is input when the auxiliary tray is not in use. It is possible to prevent a large-size sheet from being stacked without using the printer.

According to the invention of claim 16 or 22,
When the auxiliary tray is used, a configuration is adopted in which the amount of paper loaded on the first paper feed tray is limited, so that a drive source corresponding to small-size paper can be used as it is, and cost increase due to providing a large-capacity drive source can be prevented. .

According to the invention of claim 17 or 22,
Since the sheet stacking amount is limited by setting the lower limit position of the first sheet feeding tray upward, the sheet stacking amount can be reliably limited with a simple configuration.

According to the invention described in claim 18 or 22,
When the auxiliary tray is used, the stacking of the sheets on the second sheet feed tray is prohibited, so that the overload driving means can be reliably prevented from being overloaded.

According to the invention described in claim 19 or 22,
Since the use of the auxiliary tray is prohibited when paper is present in the second paper feed tray, it is possible to reliably prevent an overload of the lifting drive means.

According to the invention described in claim 20 or 22,
Since the first paper feed tray is configured to be manually liftable, the setting of the auxiliary tray can be facilitated.

According to the invention of claim 21 or 22,
At least a first sheet feed tray, a lifting drive means,
Is integrated as a detachable unit with respect to the apparatus body, and the first sheet tray is provided so as not to be automatically lowered when the unit is pulled out from the apparatus body. Further, it is possible to prevent an accident such as breakage of the auxiliary tray in pulling out the sheet feeding unit.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing a sheet feeding device according to an embodiment of the present invention, wherein FIG. 1A is a schematic plan view and FIG.

FIG. 2 is a schematic front view of a state in which a first sheet feeding tray is raised to a sheet feeding position in a state where an auxiliary tray is pulled out and large-sized sheets are stacked.

FIG. 3 is a perspective view showing a drawer configuration of an auxiliary tray.

FIG. 4 is a schematic plan view showing a state where an auxiliary tray is stored and sheets are not stacked.

FIG. 5 is a schematic plan view showing an engagement configuration between an auxiliary tray for giving a click feeling and a first paper feed tray.

FIG. 6 is a schematic plan view showing a withdrawal amount detecting unit.

FIG. 7 is a flowchart of end fence control based on a detection result of a withdrawal amount detection unit.

FIG. 8 is a schematic front view illustrating a lower limit position of a first sheet feeding tray corresponding to a sheet size (A3).

FIG. 9 is a schematic front view illustrating a lower limit position of a first sheet feed tray corresponding to a sheet size (B4).

FIG. 10 is a schematic front view of a stencil printing machine as an image forming apparatus.

FIG. 11 is a diagram when small-size paper is used,
(A) is a schematic plan view, (b) is a schematic front view.

FIG. 12 is a schematic front view showing a sheet feeding unit.

13A and 13B are diagrams illustrating a sheet detecting unit, wherein FIG. 13A is a schematic plan view during non-operation and FIG. 13B is a schematic plan view during operation.

FIG. 14 is a schematic front view illustrating a state in which a small-size sheet is used and the first sheet feed tray returns to the lower limit position due to the absence of sheets on the first sheet feed tray.

FIG. 15 is a schematic front view showing a state in which sheets stacked on a second sheet tray are transferred to a first sheet tray;

FIG. 16 is a schematic front view showing a state in which the first and second paper trays have run out of paper.

FIG. 17 is a schematic plan view in another embodiment.

FIG. 18 is a schematic plan view in another embodiment.

[Explanation of symbols]

 3a Second paper feed tray 3b, 3b Opening 11 First paper feed tray 14 End fence as paper transfer means 70 Paper supply means 72 Auxiliary tray 76 Pull-out amount detection means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B65H 7/04 B65H 7/04 F term (Reference) 3F048 AA02 AA04 AA05 AB01 BA02 BA07 BB02 BB10 CB03 DA01 DC05 DC09 3F343 FA02 FB02 FB03 FB05 FC18 GA01 GB01 GC01 GD02 GE02 HA16 HA22 HB03 HB04 HC23 HC26 HC28 HD16 KB03 LA04 LA13 LA14 LC12 LC20

Claims (22)

[Claims] A first paper feed tray capable of stacking and storing a plurality of papers and moving up and down; a lifting drive means for raising and lowering the first paper feed tray; Sheet feeding means for feeding sheets one by one, a second sheet feeding tray capable of stacking and storing a plurality of sheets and provided in parallel with the first sheet feeding tray, and a first sheet feeding tray Paper transport means for transporting the paper loaded on the second paper feed tray to the first paper feed tray while the first and second paper feed trays are substantially horizontal.
A sheet feeding device having an auxiliary tray that is provided in the sheet feeding tray so as to be freely retractable and protrudes from the first sheet feeding tray and extends to a sheet stacking area of the second sheet feeding tray. 2. The paper feeding device according to claim 1, wherein the auxiliary tray is configured to be pulled out substantially horizontally to the second paper feeding tray side. 3. The paper feeding device according to claim 2, wherein an opening is formed in the second paper feeding tray to allow the drawn-out auxiliary tray to pass vertically. . 4. The paper feeder according to claim 2, wherein when the auxiliary tray is pulled out, there is a click feeling for distinguishing the paper size due to engagement with the first paper feed tray. A sheet feeding device characterized by the above-mentioned. 5. The paper feeder according to claim 2, further comprising a drawer amount detector for detecting a drawer amount of the auxiliary tray. 6. The sheet feeding device according to claim 5, wherein the position of the sheet transfer means is automatically changed to an appropriate position as an end fence according to the amount of withdrawal detected by the withdrawal amount detecting means. Paper feeder. 7. A sheet feeding device according to claim 1, further comprising a sheet detecting means for detecting the presence or absence of a sheet between the first sheet feeding tray and the second sheet feeding tray. When small-size sheets are individually stacked on the first sheet tray and the second sheet tray, when the sheet detecting means detects that there is a sheet, it is determined that the sheet is set abnormally, and the auxiliary tray is set. When a large-size sheet is stacked on the first sheet feed tray and detected by the sheet detecting means, the setting of the sheet size change information does not cause a setting error. Paper equipment. 8. The paper feeding device according to claim 7, further comprising means for detecting a use state of the auxiliary tray, and inputting paper size change information to a large-sized sheet when the auxiliary tray is not in use. A paper feeder, which issues a warning when the operation is performed. 9. The paper feeding device according to claim 1, wherein a loading amount of paper on the first paper feeding tray is limited when the auxiliary tray is used. apparatus. 10. The paper feeding device according to claim 9, wherein the amount of paper loaded is limited by setting the lower limit position of the first paper feeding tray upward. . 11. The sheet feeding device according to claim 9, wherein a limit amount of sheet stacking on the first sheet feeding tray is changed according to an amount of pulling out of the auxiliary tray. 12. The sheet feeding device according to claim 1, wherein the auxiliary tray is configured to rotate in a vertical direction and fall down substantially horizontally. 13. The paper feeding device according to claim 1, wherein the auxiliary tray is configured to be pulled out by being rotated substantially horizontally. 14. A sheet feeding device according to claim 12, further comprising a sheet detecting means for detecting the presence or absence of a sheet between the first sheet feeding tray and the second sheet feeding tray. When small-sized sheets are individually stacked on the paper tray and the second sheet supply tray, if the sheet detection means detects that there is a sheet, it is determined that the sheet is set abnormally, and the first tray is used by using the auxiliary tray. A sheet feeding device, wherein when a sheet of large size is stacked on a sheet feeding tray and detected by the sheet detecting means, sheet size change information is input and a setting error does not occur. 15. The paper feeding device according to claim 14, further comprising means for detecting a use state of the auxiliary tray, and inputting paper size change information to a large-size sheet when the auxiliary tray is not in use. A paper feeder, which issues a warning when the operation is performed. 16. The sheet feeding device according to claim 12, wherein a loading amount of sheets on the first sheet feeding tray is limited when the auxiliary tray is used. apparatus. 17. The paper feeding device according to claim 16, wherein the paper stacking amount is limited by setting a lower limit position of the first paper feeding tray upward. . 18. The sheet feeding device according to claim 1, wherein when the auxiliary tray is used, loading of sheets on the second sheet feeding tray is prohibited. apparatus. 19. The sheet feeding device according to claim 1, wherein when a sheet is present in the second sheet feeding tray, use of the auxiliary tray is prohibited. Paper equipment. 20. The sheet feeding device according to claim 1, wherein the first sheet feeding tray can be manually moved up and down. 21. The sheet feeding device according to claim 1, wherein at least a first sheet feeding tray, the elevation drive unit,
The second paper feed tray is integrated as a detachable unit with respect to the apparatus main body, and the first paper feed tray is provided so as not to be automatically lowered when the unit is pulled out from the apparatus main body. Characteristic paper feeder. 22. An image forming apparatus for forming an image on a sheet fed one by one from a sheet feeding device, wherein the sheet feeding device is the one according to any one of claims 1 to 21. Characteristic image forming apparatus.