JP2005075491A - Manual paper feed device of image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manual paper feed device of an image forming apparatus, coping with a lot of operation patterns and discriminating a directional error of a main fixed form size by disposing a detection means for detecting the state of an extension member in such a position that even if a manual paper feed table itself is smaller than the width of A4-size, the extension member is extended to detect a directional error of the fixed form size having the same width. <P>SOLUTION: This manual paper feed device includes: a manual paper feed table 16 set with the paper sheets 17 directed to a paper feed port; a paper width detection means for detecting the width of paper sheets on the manual paper feed table 16; and an extension member 15 stored in the manual paper feed table 16 and extended. A paper detection means 18 for detecting the presence/absence of a paper sheet is provided in a predetermined position of the extension member 15, whereby the size of the paper sheet is determined according to combined results of the paper detection means and the paper width detection means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a manual sheet feeding device that can be used in an image forming apparatus such as a copying machine, a facsimile machine, and a printer.

  In general, in an image forming apparatus, plain paper is mainly set in a large-capacity paper feed tray, but in order to handle paper that is difficult to feed from the paper feed tray, such as thick paper, film, and other special paper. In addition to the paper feed tray, a manual paper feed slot and a manual paper feed stand that can set paper in the paper feed slot are often provided.

However, although it plays an important role in increasing the number of paper types that can be used, the use frequency of manual paper feeding is remarkably low because the use frequency of plain paper is usually extremely high. For this reason, it is desired that the manual sheet feeder can be stored as small as possible on the main body side when not in use.
This requirement is also important for the purpose of designing the image forming apparatus itself to be smaller. However, since the size of paper that can be fed by manual feed is desired to be as large as possible, the manual feed tray is required to have a certain size according to the corresponding paper size. Therefore, many manual sheet feed trays can be stored small when not in use, and are opened and used only when in use.
In order to further reduce the closed state, the stacking section can be extended only when stacking large sheets of paper. For relatively small sheets, the extension member is stored in the manual feed tray and manually inserted in that state. Many are configured to close the paper feed tray.
With such a configuration, it is possible to shorten the manual sheet feeding table itself by taking a long extension portion, and there are great advantages in terms of space, but there are also disadvantages. One of them is the problem of detecting the size of the paper set on the manual paper feed tray. In general, there is a detecting means for detecting the width of the paper set on the manual paper feed table, and it is provided on many manual feed tables.

However, when only the width is detected, it is necessary for the user to input the size from the operation screen, and it is only possible to check whether the size is correct, but the orientation of the standard size paper with the same width (A3 portrait and A4 landscape, etc.) Cannot be distinguished.
Therefore, even though the user is wrong, the wrong size paper is fed to the image forming device, the image size does not match the paper size, and much toner is not transferred to the paper. Damage to the cleaning part on the photosensitive member and the photosensitive member, leading to a reduction in the life of the cleaning part.
Further, there are many cases where a plurality of sensors provided in the conveyance path in the image forming apparatus determines that the conveyance timing of the sheet is abnormal and causes a jam. Because of these problems, it is desirable to detect the length of the paper set in the manual paper feed direction in the conveyance direction, automatically determine the size of the paper, and to minimize user error.
However, the best way to provide detection means for detecting the length of the stacked paper is that the manual paper feed tray is larger than the corresponding maximum size paper. In order to be able to detect a difference in direction, it is desirable that the manual sheet feed table is larger than the width of a standard paper sheet having the same maximum width and length as the maximum standard paper size (for example, A4 horizontal or larger when dealing with up to A3 vertical).
Otherwise, the trailing edge of the set paper will protrude from the manual paper feed table, making it difficult to detect the position of the trailing edge. However, in order to secure this size, the space for the manual paper feed tray when stored is increased, leading to an increase in the size of the image forming apparatus main body.
Accordingly, an object of the present invention is to solve the above-described problems by using a detecting means for detecting the state of the extension member, even if the manual sheet feeding base itself is smaller than the A4 side, if the extension member is extended, the detection means has the same width. By placing it in a position that can detect the difference in the direction of the standard size paper, it is possible to deal with many patterns of use, and it is possible to distinguish the direction of the main standard size paper by manually feeding the image forming apparatus. To provide an apparatus.

In order to solve the above-described problems, in the invention described in claim 1, a manual sheet feed table capable of stacking sheets of paper toward a sheet feed port, and a sheet width detection for detecting the width of the sheet on the manual sheet feed table. And a manual sheet feeder provided with an extendable member that can be stored in the manual sheet feed table and can be extended, and includes a sheet presence / absence detecting unit that detects presence / absence of a sheet at a predetermined position of the extension member. The manual feed device of the image forming apparatus characterized in that the size of the paper is determined in combination with the detection result of the means is the main feature.
According to a second aspect of the present invention, there is provided detection means for detecting whether the extension member is housed or extended, the detection result and the detection result of the paper width detection means, 2. A manual sheet feeding device for an image forming apparatus according to claim 1, wherein the size of the sheet is determined in combination with the detection result of the sheet presence / absence detection means.
According to a third aspect of the present invention, there is provided the manual sheet feeding device of the image forming apparatus according to the first or second aspect, wherein the position of the sheet presence / absence detecting means is in a range of 210 mm or more and 297 mm or less from the leading edge of the sheet set normally. Main features.

According to the first aspect, it is possible to detect whether or not there is a sheet on the sheet presence / absence detection sensor by closing the sheet presence / absence detection sensor (length detection sensor) that detects the presence / absence of the sheet. It is possible to cope with many usage patterns.
According to the second aspect of the present invention, the detecting means for detecting whether the extension member is housed or extended is provided, the detection result, the detection result of the paper width, the detection result of the presence of the paper, Since the sheet size is determined by combining the above, it is possible to distinguish the direction difference of the main standard size.
According to the third aspect, since the position of the sheet presence / absence detection means is in the range of 210 mm or more and 297 mm or less from the leading edge of the sheet set normally, it can cope with main standard sizes.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing an image forming apparatus main body using a manual sheet feeding device according to the present invention. In the image forming apparatus A shown in FIG. 1, a sheet is set in the sheet feeding cassette 21, and the sheet is fed from a sheet feeding unit formed by a pickup roller 25 and a feed roller 26 and conveyed to the registration roller 23.
On the other hand, the image is formed as a toner image by the image forming unit 6 arranged horizontally four above and is transferred to the intermediate transfer belt 10. The sheet is temporarily stopped with the leading end abutting against the registration roller 23 and the timing is adjusted. Then, the sheet passes between the transfer roller 37 and the intermediate transfer belt 10 while the image is transferred, and the fixing unit 40 and the discharge roller 40 are discharged. The paper is discharged onto the paper discharge tray 4 through the paper roller 30.
On the right side of the registration unit composed of the registration rollers 23, a manual sheet feeding unit including a pickup roller 13, a feed roller 11, and a reverse roller 12 is provided, and manual sheet feeding for stacking sheets fed from the manual sheet feeding unit. A table 16 is provided to be openable and closable.
FIG. 2 is a perspective view showing an embodiment of the manual sheet feed table according to the present invention in a closed state. FIG. 3 is a perspective view showing a state in which the extension sheet attached to the manual sheet feed table is closed while the manual sheet feed table is open.

FIG. 4 is a perspective view showing a state in which the manual sheet feed stand is opened and the extension member is opened. FIG. 5 is a perspective view showing a state in which a sheet of LT side (direction in which the transport direction is short) is stacked on the manual sheet feed table of FIG. FIG. 6 is a side view showing a state in which a sheet of LT side (direction in which the transport direction is short) is stacked on the manual sheet feed table of FIG.
As shown in FIGS. 2 to 6, FIG. 2 shows a state in which the manual feed tray 16 is closed, and FIG. 3 shows a state in which the manual feed tray is open and is rotatably attached to the manual feed tray. The extension member 15 is in a closed state. The extension member 15 is a long and thin plate-like member, and one end of each of the extension members 15 is pivotally supported by the front end portion of the sheet feed table main body so as to be rotatable in the lateral direction. The extension member 15 can shift from the stored state of FIG. 3 to the open state of FIG.
FIG. 4 shows a state in which the manual paper feed tray 16 is open and the extension member 15 is open. When in use, the paper is stacked on the manual paper feed tray 16 so that the front end of the paper is positioned downstream of the pickup roller 13 in the transport direction.
Then, the side fences 14a and 14b can be fed after aligning the position of the sheet 17 to the center and aligning the bundle. Although not shown in the drawing, a paper width detecting means (not shown) for detecting the width of the paper in conjunction with the side fences 14a and 14b is provided in the manual paper feed tray 16, so that the side fences 14a and 14b are provided. The width of the paper is detected by matching the width of the paper.
The manual sheet feeder is configured to stack a manual sheet feeder 16 on which a sheet 17 can be stacked at a predetermined position with a sheet feeding opening, a sheet width detection unit (not shown) that detects the width of the sheet 17, and a small-sized sheet. An extension member 15 that is stored in the manual paper feed tray 16 and can be extended to hold the trailing edge of the paper only when a large size of paper is stacked.
A sheet presence / absence detection unit 18 for detecting the presence / absence of a sheet is provided at a predetermined position of the extension member 15, and the size of the sheet is determined in combination with the detection result of the sheet width detection unit.

FIG. 5 and FIG. 6 show a state in which the sheets 17 of the LT side (direction in which the transport direction is short) are stacked. The sheet presence / absence detection sensor that detects the presence / absence of the sheet is the reflection type sensor (hereinafter referred to as a length detection sensor) 18 in FIG. 4, and the sheet is blocked on the length detection sensor 18 by blocking the sheet on the sensor. It is possible to detect that there is.
The manual paper feed unit of this embodiment has a corresponding size ranging from A6 to double letter (DLT), and the main standard sizes with the same width and different paper orientation are A3 portrait, A4 landscape, and A4. Vertical and A5 horizontal, B4 vertical and B5 horizontal, DLT vertical and LT vertical.
These combinations of sizes are relatively frequently used by the user, and there are many cases where the size input to the operation unit of the main body and the set paper are mistaken. However, if only the width is detected, the difference between A3 portrait and A4 landscape cannot be distinguished, and if the user sets it incorrectly, the machine will be damaged.
Therefore, it is desirable to provide a sensor at a position upstream of the A4 side in the transport direction to detect the size of the paper set on the manual paper feed tray 16. However, when not used, it is necessary to store the manual paper feed tray 16 in a limited space of the main body, and the manual paper feed tray 16 itself cannot be enlarged.

In the case of the present embodiment, it is very difficult to increase the size of the manual feed tray 16 to a size that allows the A4 side to be completely stacked up to the rear end. Since it is impossible to attach 18, the length detection sensor 18 is attached to the extension member 15. In this way, the length detection sensor 18 is configured to reduce the size of the manual paper feed tray 16 during storage and to determine the difference between A4 horizontal and A3 vertical.
However, in this state, there is no problem when the extension member 15 is opened and used. However, when the extension member 15 is closed and used, there is a sheet on the length detection sensor 18 even on the side of A4, and determination is impossible. become.
Actually, the extension member 15 is opened when the paper is somewhat larger than the manual paper feed tray 16, and when setting a paper that slightly protrudes from the manual paper feed tray 16 such as A4 side or LT side. Normally, the extension member 15 is not opened.
In addition to the fact that less time is required for the operation, there is an advantage that a user who rarely uses long sheets can use the space where the extension member 15 opens for another purpose. In order to solve the problem, in this embodiment, an extension member open / close detection means for detecting whether the extension member 15 is in an open state or a closed state is provided.

FIG. 7 is a perspective view for explaining extension member opening / closing detection means for detecting opening / closing of the extension member. As shown in FIG. 7, a photo interrupter 19 is provided in the groove 16 a of the manual sheet feeding table, and the extension member 15 is closed or opened depending on whether or not the rib 15 a of the extension member 15 is in the photo interrupter 19. Can be detected. That is, the position of the groove 16a is located on the path for rotating the rib 15a on the lower surface of the extension member 15, and when the extension member 15 is stored on the paper feed table side, the rib 15a is fitted in the groove 16a. To do.
A control unit (not shown) can determine the difference in direction even if the width is the same by determining the detection result in combination with the detection result of the width and the detection result of the length detection sensor. The determination by the control means is as shown in the following table. In the case of A4 side, when the extension member 15 is closed, it is determined that the A4 side is present even if the length detection sensor 18 is ON.
The manual paper feed tray 16 of the present embodiment has a length of about 200 mm from the leading edge of the set paper, and is A4 length (long side length 297 mm), LT length (long side length 279.4 mm). In order to maintain the extension member 15, the extension member 15 must be used.
In addition, even if the extension member 15 is closed on the A5 side and the B5 side, the sheet does not hang over the length detection. Therefore, if the length detection is ON with the extension member 15 closed, the A4 portrait and the B4 portrait are displayed. judge.
In the following cases, the longest in the transport direction in the horizontal set (short side is the transport direction) is 216 mm in the horizontal direction of LT, and the shortest in the vertical set (the long side is in the transport direction) is 297 mm in the A4 vertical direction It is.
Therefore, if the position of the length detection sensor 18 is in the range of 216 mm or more and 297 mm or less from the leading edge of the set paper, the main standard size can be handled.






















table

  Applicability of the present invention includes image forming apparatuses such as copying machines, facsimile machines, and printers.

1 is a schematic diagram illustrating an image forming apparatus main body that uses a manual sheet feeder according to the present invention. The perspective view which shows the embodiment of the manual paper feed stand by this invention in the closed state. The perspective view which shows the state which the extension member attached to the manual feed stand so that rotation was possible with the manual feed stand open. FIG. 6 is a perspective view illustrating a state in which a manual sheet feeding base is opened and an extension member is opened. FIG. 5 is a perspective view illustrating a state in which a sheet of LT side (direction in which the conveyance direction is short) is stacked on the manual sheet feeding table of FIG. 4. FIG. 5 is a side view showing a state in which LT side paper (direction in which the transport direction is short) is stacked on the manual paper feed tray of FIG. 4. The perspective view explaining the detection means which detects opening and closing of an extension member.

Explanation of symbols

A Image forming apparatus 15 Extension member 16 Manual paper feed tray 17 Paper 18 Paper presence / absence detection means (length detection sensor)
19 Extension member open / close detection means (photo interrupter)

Claims (3)

  A manual sheet feed table capable of stacking sheets of paper toward the sheet feed slot, a sheet width detecting means for detecting the width of the sheet on the manual sheet feed table, and an extension member that can be stored and extended in the manual sheet feed table In the manual sheet feeding device, a sheet presence / absence detection unit that detects the presence / absence of a sheet is provided at a predetermined position of the extension member, and the size of the sheet is determined in combination with the detection result of the sheet width detection unit. A manual paper feeder of the image forming apparatus.   Detection means for detecting whether the extension member is housed or extended is provided, the detection result, the detection result of the paper width detection means, the detection result of the paper presence / absence detection means, The manual sheet feeding device of the image forming apparatus according to claim 1, wherein the size of the sheet is determined by combining the two.   The manual sheet feeding device of the image forming apparatus according to claim 1, wherein the position of the sheet presence / absence detection unit is in a range of 210 mm or more and 297 mm or less from a leading edge of a normally set sheet.

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