JP2006103953A - Paper size detection device, paper feeding tray, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper size detection device capable of facilitating assembly and having a simple structure. <P>SOLUTION: This paper size detection device has a paper feeding tray main body for holding papers having arbitrary size in a stacked condition, an end fence arranged to move freely in the direction of delivery of paper for the paper loaded in the tray main body to regulate a rear end position of the loaded paper, a link engaging with a part of the end fence, moving in the direction crossing the direction of slide of the end face orthogonally in accordance with slide travel of the end fence, and provided with a recessed and projecting pattern, and a paper size signal generating part constituted by a plurality of detection elements provided and fixed at positions of an image forming device main body by corresponding to the recessed and projecting pattern of the link. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a paper size detection device used in an image forming apparatus such as a copying machine, a printer, a facsimile machine, a printing machine, or a combination of these, and in particular regulates the paper in the paper feeding direction according to the paper size. The present invention relates to a paper size detection device used for a paper feed tray to be accommodated.

In image forming apparatuses such as copying machines and printers, various sizes of paper are used according to the purpose of use. Some of these devices include a tray that can load and pass various sizes of paper according to the purpose of use. In this case, an image is formed according to the size and orientation of the paper to be used. It is necessary to detect the size and orientation of the paper loaded on the tray. For this reason, a tray that can stack and pass sheets of various sizes as described above often comes with a device that automatically detects the sheet size.
As a conventional example of the paper size detection device, for example, there is one described in Patent Document 1. The paper size detection device described in Patent Document 1 is provided via a segment gear and an idle gear that are provided on a paper tray and rotate with a slide movement of an end fence that regulates the rear end position with respect to the paper feeding direction. The paper size is detected by the position pattern of the rack that moves in synchronization with the end fence.
Another example is described in Patent Document 2, for example. The paper size detection device described in this publication is characterized in that the guide groove that engages with the end fence provided on the segment gear in Patent Document 1 has a step shape, and thus the paper to be used The size is detected more accurately.
JP-A-7-251951 Japanese Patent Application Laid-Open No. 11-165881

However, since all of the above-described size detection devices are mechanisms that rotate about the axis, it is necessary to screw the center of the segment gear, and an idle gear that moves in conjunction with the movement of the segment gear, Since the paper size detection plate is moved using a rack or the like, the positional relationship between the segment gears and the rack must be strictly defined, and there is a problem that the assemblability is not easy.
Further, in the size detection device, the size detection element must be installed in parallel with the moving direction of the end fence, but depending on the tray insertion / removal direction, the size detection element does not interfere with the tray insertion / removal. For this reason, there is a problem that a complicated structure is required.
The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a paper size detection device that is easy to assemble and has a simple structure.

In order to solve the above problems, the invention described in claim 1 is a paper feed tray main body that holds papers of any size in a stacked state, and moves in the paper feeding direction with respect to the paper stacked on the tray main body. An end fence that regulates the rear end position of freely placed and loaded paper, and an unevenness that engages with a part of the end fence and moves in a direction perpendicular to the slide direction of the end fence as the end fence slides A paper size detection device having a link having a pattern and a paper size signal generation unit configured by a plurality of detection elements fixedly positioned on the image forming apparatus main body corresponding to the concave / convex pattern of the link is the most main. Features.
According to the second aspect of the present invention, there is provided a paper feed tray main body that holds papers of any size in a stacked state, and a paper tray that is movably disposed in a direction perpendicular to the paper feed direction with respect to the paper stacked on the tray main body. A side fence that regulates the width position of the printed paper, and a link that has an uneven pattern that engages with a part of the side fence and moves in a direction perpendicular to the sliding direction of the side fence as the side fence slides. The most important feature is a paper size detection device having a paper size signal generation unit composed of a plurality of detection elements provided in a fixed position in the image forming apparatus main body corresponding to the concave / convex pattern of the link.
According to a third aspect of the present invention, the link includes a rack gear along a moving direction thereof, and transmits position information of the end fence via an idle gear engaged with the rack gear. Is the main feature.
According to a fourth aspect of the present invention, the paper size signal generation unit is arranged in an L shape with respect to a plane parallel to a moving direction of a link engaged with the side fence and the end fence. The main feature is the paper size detection device.
According to a fifth aspect of the present invention, the paper size detecting device according to the first aspect is characterized in that the insertion / extraction direction of the tray body is set to a direction that coincides with the paper feeding direction.
According to a sixth aspect of the present invention, the main feature is a paper feed tray including the paper size detecting device according to any one of the first to fifth aspects.
According to a seventh aspect of the present invention, the paper feed tray according to the sixth aspect is provided.

According to the present invention, a member provided with a concavo-convex pattern for transmitting paper size information to a paper size detecting element provided in the main body of the image forming apparatus is formed integrally with a link that moves in synchronization with the movement of the end fence. In addition, since the link that moves synchronously with the end fence is configured by fitting with a hook shape to the paper feed tray, assembling is facilitated.
According to the present invention, the member provided with the concave / convex pattern for transmitting the paper size information to the paper size detecting element provided in the main body of the image forming apparatus is formed integrally with the link moving in synchronization with the movement of the side fence. Further, the link that moves synchronously with the side fence is formed by fitting the paper feed tray with a hook shape, so that the assembly is facilitated.
The paper feed tray according to the present invention detects the size of the stacked paper from the position information of the end fence and the position information of the side fence, and thus enables highly accurate paper size detection.
The paper size detection apparatus according to the present invention enables to change the installation direction of the paper size detection plate freely in the paper size detection apparatus according to claim 1 or claim 2. For this reason, for example, if the detection unit is installed at a position lateral to the tray insertion / removal direction, the detection plate and the element may come into contact with each other during the tray insertion / removal, or the space where the detection unit is provided on the back side of the tray insertion / removal direction. It is possible to change the direction of the detection unit when there is no error.
The paper size detection apparatus of the present invention can detect eight types of paper sizes by using three detection elements, and can save space in the detection unit.
In the paper feed tray according to the present invention, the direction in which the paper feed tray main body is inserted into and removed from the image forming apparatus is the same as the paper feed direction, so that the impact of the impact upon insertion / extraction on the detection of the detection mechanism can be reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a paper feed tray of this embodiment. The paper feed tray 1 holds sheets in a stacked state on a bottom plate (not shown), an end fence 2 that regulates the rear end position of the sheets stacked on the bottom plate, and a side fence 3 that regulates the stacked sheets in the width direction. And.
Here, there are eight types of paper feed trays of this embodiment: DLT size, A3 horizontal size, B4 horizontal size, A4 horizontal size, LT size, A4 vertical size, B5 vertical size, and A5 vertical size, from the largest. The size of the paper can be detected, and the end fence is slidably mounted in the paper feeding direction according to such various paper sizes.
FIG. 2 is a plan view showing the paper size detection device, and FIG. 3 is a front view showing the paper size detection device. A paper size conversion link 4 that engages with a part of the end fence and moves in a different direction synchronously is disposed on the back side of the bottom plate of the paper feed tray. This paper size conversion link is fitted in the engaged portion 1a of the paper feed tray body by hook-shaped structures 5 provided at both ends, and slides in a direction perpendicular to the moving direction (paper feeding direction) of the end fence 2. It is configured freely. The link 4 is provided with a concavo-convex pattern 6 at a portion corresponding to its end (left end in the figure), and the concavo-convex pattern 6 faces the paper size detecting element 7 installed in the image forming apparatus main body.
The end fence 2 is integrally formed with an engaging portion 2a extending downward at the lower portion thereof, and the engaging portion 2a at the lower end fence is provided with a slit 1b provided in the sheet feeding tray body and a sheet size conversion link body. The engagement between the end fence 2 and the paper size conversion link 4 is realized with a structure penetrating both of the four cam grooves 8 (cam slits). That is, when the end fence 2 is moved in the paper feeding direction in accordance with the paper size, the engagement portion 2a at the lower end of the end fence is moved while sliding in the cam groove 8 and the paper size conversion link 4 is moved accordingly. Accordingly, the sheet moves in a direction orthogonal to the end fence, and the sheet size information is transmitted to the sheet size detecting element 9 through the uneven pattern. As shown in the figure, the cam groove 8 as a through slit extends non-linearly (zigzag), and has a configuration in which portions parallel to the sheet feeding direction and oblique portions are alternately connected.
The concavo-convex pattern 6 is provided with a plurality of protrusions as protrusions extending in the lateral direction, each having a different vertical position, lateral position, and lateral length. A plurality of corresponding sensor portions 7 are also arranged at appropriate heights so that these protrusions can be detected. The control means determines the position (paper size) of the end fence based on the combination of on / off by turning on / off each sensor unit 7 in the process in which the individual protrusions 6 move laterally with respect to each sensor unit 7. Can do. The uneven pattern 6 (projection) and the sensor unit 7 constitute a paper size signal generation unit.

FIG. 4 shows the paper size detection principle by movement of the uneven pattern. The paper size detection elements 7 are arranged in an L shape so as to face the concave / convex pattern 6. The link 4 (uneven pattern 6) moves to the left and right (lateral direction) in conjunction with the slide of the paper size conversion link 4, and the switch is turned on and off by blocking the sensor unit 7 (photo interrupter) of the size detection element. A control means (CPU) (not shown) determines the paper size based on the ON / OFF result of each sensor unit 7. As described above, there are eight types of paper sizes to be detected, but the detection unit of the present embodiment can detect by turning on and off the three switches. As an example, Table 1 shows the correspondence between the on / off states of the switches SW1, SW2, and SW3 and the paper size.
[Table 1]

As shown in FIG. 2, the cam groove 8 formed in the paper size conversion link 4 makes the movement amount of the uneven pattern 6 that moves according to the position of the end fence corresponding to the paper of each size uniform for each size. Is formed. That is, eight points are taken so that the slide position of the paper size conversion link is equal to the end fence position corresponding to eight types of paper sizes, and a line that smoothly connects the points is formed as a cam groove. To do. Also, in order to prevent the positional deviation due to the play of the end fence from affecting the size detection one by one, a linear groove corresponding to the play in the movement direction of the end fence is formed near the end fence position corresponding to the paper size. . As a result, even if the operator does not contact the end fence at the end of the paper and fixes it with a little margin when setting the paper size, the paper size is not erroneously detected.
In the above embodiment, the paper size is detected by using the paper size conversion link 4 that moves in the width direction in response to the movement of the end fence. You may apply to the side fence which regulates. That is, the link 4 may be assembled to at least one of the side fences, and the size may be detected by the same configuration. That is, a paper feed tray main body 1 that holds sheets of any size in a stacked state, and a stack of sheets that are movably arranged in a direction perpendicular to the paper feeding direction with respect to the paper stacked on the tray main body 1. A side fence 3 that regulates the width position, a link 4 that includes a concave and convex pattern that engages with a part of the side fence 3 and moves in a direction perpendicular to the sliding direction of the side fence as the side fence slides, A paper size signal generation unit configured by a plurality of detection elements 7 provided in a fixed position on the image forming apparatus main body corresponding to the uneven pattern 6 of the link 4 may be provided.

FIG. 5 shows a structure in which a paper size detection device is provided in the back of the tray insertion / removal direction via an idle gear. The paper size conversion link 4 that engages and slides with the end fence 2 has a structure in which a rack gear 9 is integrally provided. A size detection plate 10 having a concavo-convex pattern 10a is disposed at the back of the paper feed tray insertion / removal direction, and is opposed to the paper size detection element 20 installed in the image forming apparatus main body. The size detection plate 10 is fitted in the tray body 1 by a hook-shaped structure, and is configured to be slidable in the end fence moving direction.
The size detection plate 10 and the paper size detection element 20 constitute a paper size signal generation unit.
Further, the paper detection plate 10 is integrally provided with a rack gear 11 at a portion located on the back side of the paper feed tray, and is engaged with the rack gear 9 of the link via a stepped idle gear 12. That is, when the end fence 2 is moved forward and backward in accordance with the paper size in parallel with the paper feeding direction, the paper size conversion link 4 moves in a direction perpendicular to the end fence 2 accordingly, and the idle gear 12 accordingly. Then, the paper detection plate 10 moves in the direction parallel to the end fence, and the paper size information is transmitted to the paper size detection element 20 through the concave / convex pattern 10a.

As described above, according to the present invention, the member provided with the concavo-convex pattern 6 for transmitting the paper size information to the paper size detection element provided in the image forming apparatus main body is connected to the link 4 that moves in synchronization with the movement of the end fence. Since they are integrally formed, a simple configuration can be achieved, and the link 2 that moves synchronously with the end fence 2 is configured by fitting into the paper feed tray in the form of a hook, so that assembly is facilitated.
Further, since the size of the stacked paper is detected from the position information of the end fence 2 and the position information of the side fence 3, it is possible to detect the paper size with high accuracy.
Further, it is possible to freely change the installation direction of the paper size detection plate. For this reason, for example, if the detection unit is installed at a position lateral to the tray insertion / removal direction, there is a possibility that the detection plate and the element may come into contact with each other during the tray insertion / removal or the space where the detection unit is provided on the back side in the tray insertion / removal direction. It is possible to change the direction of the detection unit when there is no error.
In addition, eight types of paper sizes can be detected by three detection elements, and the detection unit can be made space-saving.
Further, the direction in which the paper feed tray body is inserted into and removed from the image forming apparatus is set to the same direction as the paper feeding direction, so that it is possible to reduce the influence of the impact at the time of insertion and removal on the detection of the detection mechanism.
The paper feed tray of the present invention can be applied to a paper feed unit of an image forming apparatus such as a copying machine, a printer, or a facsimile.

The figure which shows the paper feed tray of this invention. 1 is a plan view showing a paper size detection device of the present invention. 1 is a front view showing a paper size detection device of the present invention. FIG. 4 is an explanatory diagram illustrating a paper size detection principle based on movement of an uneven pattern. Explanatory drawing which shows the structure which provided the paper size detection apparatus in the tray insertion / extraction direction back | inner via the idle gear.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feed tray 2 End fence 3 Side fence 4 Paper size conversion link 5 Detachable hook 6 Uneven pattern 7 Paper size detection element 8 Cam groove 9 Rack gear 10 Size detection plate 11 Rack gear 12 Idle gear

Claims (7)

  The paper feed tray body that holds paper of any size in a stacked state, and the rear end position of the loaded paper that is movably arranged in the paper feed direction with respect to the paper stacked on the paper feed tray body is regulated An end fence that engages with a part of the end fence, and a link having an uneven pattern that moves in a direction perpendicular to the slide direction of the end fence as the end fence slides, and the unevenness of the link A paper size detection device comprising: a paper size signal generation unit configured by a plurality of detection elements provided in a fixed position on the image forming apparatus main body corresponding to a pattern.   The paper feed tray body that holds paper of any size in a stacked state, and the width position of the loaded paper placed in the direction perpendicular to the paper feed direction with respect to the paper stacked on the tray body is regulated Corresponds to the side fence to be engaged, the link with the uneven pattern that engages with a part of the side fence and moves in the direction perpendicular to the sliding direction of the side fence as the side fence slides, and the uneven pattern of the link And a paper size signal generation unit configured by a plurality of detection elements provided in a fixed position on the image forming apparatus main body.   The paper size detection device according to claim 1, wherein the link includes a rack gear along a moving direction thereof, and transmits position information of the end fence via an idle gear meshing with the rack gear.   2. The detection elements constituting the paper size signal generation unit are arranged in an L shape with respect to a plane parallel to a moving direction of a link engaged with the side fence and the end fence. The paper size detection device according to claim 2 or 2.   The paper size detection apparatus according to claim 1, wherein a direction in which the tray main body is inserted and removed is set to a direction that matches the paper feeding direction.   A paper feed tray comprising the paper size detection device according to any one of claims 1 to 5. An image forming apparatus comprising the paper feed tray according to claim 6.

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