JP3090167B2 - Sheet size detection device and image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet size detecting apparatus for an image forming apparatus such as an electrophotographic apparatus.

2. Description of the Related Art Conventionally, there is a conventional manual sheet feeding unit of a sheet conveying device of an image forming apparatus which has a sheet feeding tray capable of loading a plurality of sheets near a sheet feeding port. . The sheet feeding unit has sheet feeding means for sequentially feeding the sheets placed on the tray one by one. As means for detecting the size of the sheet placed on this tray in the direction perpendicular to the feeding direction, FIG.
As shown in FIG. 2, there is a type having a detecting means for detecting the position of a pair of guide regulating plates 15 provided for determining the position of the sheet.

As a detection method, a method of electrically reading the position of the side regulating plate 15 has been put to practical use. Specifically, a slide volume 30 is provided on a part of the side regulating plate 15.
Are connected to each other to detect a position by reading a voltage change according to the position of the side regulating plate. <Prior art 2> Conventionally, as shown in FIG.
As the sheet feeding device 10 provided in the sheet feeding unit 0, a sheet feeding cassette 61 and a manual sheet feeding 62 are known. When the stacked sheet materials S are separated and conveyed on these sheet feeding devices, a side regulating plate for regulating the side surfaces of the sheet materials is required to prevent skew.

FIG. 15 shows a conventional example of a sheet feeding device. Since sheet materials of different sizes are stacked on the sheet feeding device, a side regulating plate 4 against which a sheet edge abuts in order to prevent skew.
1 is slidable. Further, since the rack 43 integrated with the side regulating plate 41 meshes with the gear 44, the displacement of the side regulating plate 41 can be replaced by the displacement of the rubber belt 45 via the gear 44. A top 46 is fixed to the rubber belt 45,
The size of the stacked sheet material is detected by the main body of the image forming apparatus by detecting the position of the side regulating plate 41 with the slide volume 47 by being displaced integrally with the rubber belt 45. <Prior art 3> In a conventional image forming apparatus in which transferable toner is formed on the surface of a photosensitive drum and is transferred onto a transfer material such as paper, an excess amount of toner is formed in an area corresponding to a non-sheet passing portion of the photosensitive drum. Transfer toner was adhered. In particular, when a small-sized transfer material such as a business card is used, the area corresponding to the non-sheet passing portion of the photosensitive drum further increases, and unnecessary transferable toner is consumed in large amounts. In addition, the excess toner is not transferred onto the transfer material and scatters, thereby contaminating the inside of the apparatus, causing image deterioration and various troubles. In order to solve such a problem, an invention has been made in which a size of a transfer sheet is detected in advance and a latent image at a position corresponding to a non-sheet passing area on the photosensitive drum is erased by an LED or the like.

A conventional size detecting means will be described with reference to FIG.

In FIG. 1, reference numeral 111 denotes a paper feed tray;
Copy papers are stacked and stored on the paper feed tray. The paper on the paper feed tray 111 is regulated on both sides in the width direction by guide members 112a and 112b. This guide member is provided movably in the width direction by a guide (not shown).
a, 113b and a pinion 114
And can be moved in the width direction by the same amount. Therefore, regardless of the size of the paper within the maximum width, the paper can always be placed at the center of the paper feed tray 111 in the feeding direction, and skew during paper feeding is prevented.

[0006] A slide volume 115 is mounted on the rack 113b, and the resistance is variable in accordance with the amount of movement of the guide member 112b. The amount of movement is converted into a resistance. The size of the paper on the paper feed tray 111 in the width direction can be detected.

[0007]

<Problem of Conventional Technique 1> However, in the conventional example, the side regulating plate 1
A slide volume with a longer stroke than the fifth stroke is required. Therefore, it is difficult to reduce the size of the tray. Particularly, in the case of a foldable tray that can be stored in the main body when the tray is not used, it is very difficult to reduce the size of the entire device. An object of the first invention is to provide a paper feeder that is inexpensive and can be downsized. <Problem of Conventional Technique 2> However, conventionally, when the side regulating plate 41 is moved, converted into rotation of the rubber belt 45, and the amount of displacement is detected, as shown in FIG. The rubber belt 45 is deformed, and the slide volume 47 starts to move after the top 46 is tilted (FIG. 7C).
When the rubber belt 45 moves in the direction opposite to the direction shown in FIG. 5B, the top 46 tilts to the opposite side as shown in FIG. As a result, a similar error occurs, and the position of the side regulating plate 41 cannot be accurately detected.

Accordingly, the present invention has been made in view of the above problems, and an object thereof is to eliminate deformation of the rubber belt 45 when the side regulating plate 41 moves.
The purpose is to accurately detect the position of the side regulating plate 41. <Problem of Conventional Technique 3> The paper feed tray 111 described above is
It is configured to be foldable, and can be folded except during use from the viewpoint of space saving, and therefore, it is very difficult to process a signal line tangent from the slide volume 115 to the main body. .

Further, when some external force is applied to the sheet feeding tray 111 and the sheet feeding tray 111 is detached from the main body, there is a problem that the signal line is disconnected. Furthermore, when attaching and detaching the sheet feed tray 111, the sheet feed tray 111 cannot be removed unless the signal lines are disconnected, so that attaching and detaching is very difficult.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to solve the above problems by disposing the detecting means in the image forming apparatus main body.

[0011]

<Means for Solving the Problems><Means of the First Invention> According to a first invention, a sheet feed tray capable of stacking a plurality of sheets and sheets on the sheet feed tray can be sequentially fed one by one. A sheet size detection device that detects a sheet size in a direction orthogonal to a sheet feeding direction on the sheet feeding tray. A pair of sheet regulating members for regulating a position in a direction orthogonal to the feeding direction, a synchronous gear meshing with a rack fixed to the sheet regulating member for synchronizing the movement of each sheet regulating member, A pulley is provided integrally with the gear, and a belt wound around the pulley and to which a lever of the sheet size detecting means is fixed is provided.

Further, the sheet size detecting device is a slide volume. <Means of the Second Invention> A second invention has a paper feed tray and a side regulating member for sheets on the paper feeding tray, and detects the position of the side regulating member by a movement amount detecting means. A sheet size detection device for determining the size of sheets stacked on a sheet feed tray, a belt fed by the movement of the side regulating member, a movement amount detection means and the belt held by the belt, and one end of the movement amount detection device. And a connecting piece linked to the means, wherein the connecting piece is held on the belt at two or more points separated at least on one side of the belt.

Further, the apparatus has a sheet feeding tray and a side regulating member for sheets on the sheet feeding tray, and detects the position of the side regulating member to determine the size of the sheet material stacked on the sheet feeding tray. A belt fed by the movement of the side regulating member, a moving amount conversion detecting means, and a connecting piece held on the belt and having one end linked to the detecting means. Is guided at at least two points separated in the moving direction. <Means of Third Invention> According to a third invention, at least one of a pair of regulating members for regulating the position in the width direction of a manually-inserted sheet is movably provided and manually inserted between the regulating members. A manual sheet stacking member that stacks and stores sheets, and is provided in the image forming apparatus main body so as to be detachable or foldable,
A detection unit provided in the image forming apparatus main body for detecting a movement amount of the regulation member, wherein the detection unit is arranged to engage with the regulation member and rotate with the movement of the regulation member. It is characterized by having a provided lever and a detecting unit for detecting a change in the rotation angle of the lever.

The lever of the detecting means is provided with a rotational moment in a fixed direction by an elastic member.

Further, the detection section of the detection means is a rotary volume whose resistance value changes according to a change in the rotation angle of the lever.

[0016]

<Operation><Operation of the First Invention> The detecting section for detecting the amount of movement of the sheet regulating member for regulating the width of the sheet on the sheet feeding tray and detecting the size of the sheet moves the sheet regulating member. The arm portion of the sheet size detecting means is moved via the flexible belt and thereby the sheet size is detected. By using a slide volume as the sheet size detecting means, it is possible to provide a small and inexpensive sheet size detecting unit capable of continuously detecting. <Operation of the Second Invention> When the side regulating member moves, the coupling piece moves via the rubber belt to move the slide volume, whereby the moving amount of the side regulating member is detected. By increasing the span of contact with the belt so as not to incline the coupling pieces attached to the rubber belt, the inclination of the coupling pieces can be suppressed by utilizing the belt tension. Thereby, the detection of the sheet size is performed accurately. <Operation of the Third Invention> When a sheet is stacked on the manual sheet stacking member and the regulating member is moved, the detecting unit of the detecting means detects a change in the rotation angle of the lever in conjunction with the movement of the regulating member. The size is detected. By providing the detection means in the image forming apparatus main body, the attachment / detachment or folding of the manual sheet stacking member is facilitated, and the problem of disconnection of the signal line in the above operation is eliminated.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <Embodiment of First Invention> Hereinafter, an embodiment of the first invention will be described with reference to the drawings.

As shown in FIG. 3, the manual paper feed section 1 has a manual paper feed tray 2, a paper feed roller 3 disposed in front of the manual paper feed tray 2, and a rotatable rotatable member capable of moving toward and away from the paper feed roller 3. A sheet feeding plate 5 to be pressed, a spring 6 for pressing the sheet feeding plate 5,
On the downstream side of the sheet supply plate 5,
A separation pad 7 that always contacts with a predetermined pressure and a pad spring 9 that presses the pad 7 are provided.

The manual feed tray 2 is likewise shown in FIG.
As shown in FIG. 3, the manual feed tray 1 is rotatably supported by the support shaft 11 with respect to the main body device 10. When the manual feed unit 1 is not used, the manual feed tray 2 can be folded. It is stored in the main unit 10.

The configuration of the manual feed tray 2 will be described with reference to FIG.

FIG. 2 is a diagram viewed from the direction of arrow C in FIG. In FIG. 2, reference numeral 12 denotes a tray base, and 13 denotes a tray cover. FIG. 1 is a diagram viewed from the direction E in FIG. The side regulating plate 15 is fixed so as to be slidable on the upper surface of the tray base 12 in the front and rear direction. Rack plates 16 are fixed to the side regulating plates 15, respectively. A pulley gear 17 is rotatably fixed at a substantially central portion in the front-rear direction, and the gear portion 17A meshes with each rack plate 16. Then, the other side regulating plate 15 is interlocked with the sliding operation of one side regulating plate 15.

Here, since the respective racks are meshed with the same gear, the respective side regulating plates 15 move by an equal distance from each other. The midpoint between the regulating plates 15 does not move. A flexible belt 19 is attached to a pulley portion 17B of the pulley gear 17, and an idler pulley 23 is rotatably fixed to the tray base 12 at the other end of the belt. The slide volume 20 is fixed in parallel with the parallel portion of the belt.
A lock member 22 is provided on the lever portion 21 of the slide volume.
Is fixed, and one end of the lock member is fixed to the belt 19.

Next, the operation will be described. First, when the interval between the side regulating plates is maximized, that is, when the size of the sheet that can be placed is the largest, the side regulating plates 15 are at the position indicated by A in FIG. At this time, the lever portion 21 of the slide volume 20 is at the position A, and when the sheet size is the smallest, the side regulating plate 15 is moved to the position B. With this movement, the pulley gear 17 meshing with the rack 16 fixed to the side regulating plate 15 rotates, is further decelerated by the pulley gear 17, and the belt 19 rotates. Then, the lock member 22 moves, and the lever portion 21 of the slide volume 20 moves. And
A change in the output of the volume 20 is detected by a control unit (not shown).

Here, it is obvious that the ratio of the movement amount of the rack plate 16 to the movement amount of the lever portion 21 of the volume 20 is determined by the ratio of the meshing pitch circle diameter of the gear portion 17A of the pulley gear 17 and the pulley portion 17B. Here, by using the slide volume 20 as the detecting means, it is possible to continuously detect the position at any position between the maximum size and the minimum size.

In this embodiment, as shown in FIG. 5, a hole is formed in the flexible belt 19, and the lever 21 of the slide volume 20 is penetrated and fixed to the lock member 2.
The same effect can be obtained in a form in which 2 is omitted. <Embodiment of Second Invention> Next, an embodiment of the second invention will be described with reference to the accompanying drawings.

FIG. 7 is an enlarged view of the connecting portion between the rubber belt and the connecting piece, FIG. 8 is a top view of the side regulating member of the sheet feeding device according to the present invention, and FIG. 9 is a lower view of FIG.

In FIG. 8, reference numeral 41 denotes a side regulating member which guides the side surface of the stacked sheet material S. The side regulating member 41 is slidable by fitting into the groove 42 so as to be able to cope with sheet materials S of different sizes.

In FIG. 9, a rack 43 integrated with the side regulating member 41 is engaged with a gear 44, and a pulley 48 and a pulley 49 integrated with the gear 44 have a rubber belt 45 wound therearound. By detecting the displacement of the side regulating member 41 by replacing it with the displacement of the rubber belt 45, the displacement of the side regulating member 41 can be detected.

In FIG. 7, a connecting piece 46 fixed to a rubber belt 45 wound around pulleys 48 and 49 includes:
The rubber belt 45 is sandwiched at the center thereof, and the back side of the rubber belt 45 is pressed at two positions 46a, 46a in the traveling direction. The arm 46b of the coupling piece 46
Is a slide volume 47 by the slide arm 50.
It is connected to the.

As shown in FIG. 7, the connecting piece 46 is connected to the rubber belt 45 at two points separated on one side.
When moving, even if the connecting piece 46 is inclined, the inclination is prevented by the tensile force of the rubber belt 45.

The span of the connecting piece 46 is set so as not to interfere with the pulley 48 with respect to the sliding amount of the side regulating member 41. <Another embodiment of the second invention> As another embodiment for preventing the combined top from being inclined, it is also effective to provide a guide section on the combined top itself.

FIG. 11 shows a state in which the base of the coupling piece 46 is engaged with the guide member 51 to prevent the coupling piece 46 from tilting. FIG. 12 shows a boss 46c formed at the free end of the arm of the coupling piece 46 fitted to the slide volume 47 and locked by the slide arm 50.
6 is prevented. In FIG. 13, the groove provided in the connecting piece 46 is fitted to the rib 12 to prevent the connecting piece 46 from tilting. FIG. 14 shows a state in which the projection provided on the coupling piece 46 is fitted between the two ribs 53a and 53b, and
6 is prevented. <Embodiment of Third Invention> One embodiment of the third invention will be described with a small-sized copying machine.

FIG. 17 shows a small-sized copying machine in which an image is formed by an electrophotographic method. That is, the light emitted from the light source 71 is reflected on the document on the document table 72, passes through the optical unit 73, and enters the process unit 74. Thus, a latent image is formed on the photosensitive drum 75 in the process unit 74.

Further, the size in the width direction of the sheets stacked on the manual feed tray 81 is detected in advance by a paper size detecting means which will be described in detail later. The latent image in the area corresponding to
Erased by D79 and then developed.

On the other hand, the sheets stacked on the manual feed tray 81 are separated by a known separating means, guided to the process unit 74 to transfer the preceding image, and thereafter the fixing device 7
7, and is discharged to a discharge tray 78.

FIG. 18 is a plan view of the image forming apparatus of this embodiment. Paper is stacked on the manual feed tray 81, and both sides in the width direction are regulated by guide members 82a and 82b. The guide members 82a and 83b are provided so as to be movable in the width direction by a guide (not shown), are connected to the racks 83a and 83b, respectively, and can be moved by the same amount in the width direction via the pinion 84. Is configured. Therefore, as long as the paper is within the maximum width, paper of any size can always be placed at the center of the manual feed tray 81 in the feeding direction, and skew is prevented.

A rotary volume control 87 is provided on the copying machine main body X side. A lever 86 is rotatably supported on the rotary shaft 87a. Thus, the resistance value of the volume 87 is changed. The lever 86 is given a counterclockwise moment in the figure by a spring 88 (elastic member) having one end fixed to a housing or the like. The lever 86 is provided with the abutting portion 8 extending from the guide member 82a.
5, and its rotation is regulated.

When the size of the sheets stacked on the manual feed tray 81 is small, the guide members 82a and 82b are moved to the positions indicated by broken lines in the figure. As a result, the position of the abutting portion 85 also changes, so that the lever 86
Just rotate. The resistance value of the volume 87 changes according to the rotation amount. In this way, the amount of movement of the guide members 82a and 82b provided on the
The size of the stacked sheets can be detected by converting the value into the resistance value of the volume 87 provided in the.

[0039]

According to the present invention, according to the present invention, in a sheet feeding tray provided in a manual sheet feeding port and capable of stacking a plurality of sheets, a sheet orthogonal to a sheet feeding direction is provided. A gear for synchronizing the operation of the two side regulating plates, a pulley integrated with the gear, and a flexible belt attached to the pulley, as position detecting means of the side regulating plate for detecting the size; By adopting a structure having means for transmitting the movement of the flexible belt to the slide volume, it has become possible to provide a cheaper and smaller sheet size detecting means. <Effect of the Second Invention> As described above, when the side regulating plate is moved and converted into the rotation of the rubber belt, and the displacement amount is detected,
The position of the side regulating plate could be accurately detected by not tilting the connecting piece attached to the belt. <Effect of Third Invention> As described above, by providing the image forming apparatus main body with the detecting means for detecting the length in the width direction of the stacked sheets, the manual sheet stacking member and the detecting means are provided. It is no longer necessary to connect the and the signal line. This makes it easy to attach or detach or fold the manual sheet stacking member with respect to the image forming apparatus main body.

Further, since the regulating member and the lever of the detecting means are directly engaged with each other, even if some external force is applied to the manual sheet stacking member and the manual sheet stacking member is detached from the apparatus main body, the signal line is disconnected. Does not occur.

Further, since the lever is of a rotary type, it can be made more compact than a system in which the lever moves linearly. This is particularly effective in an image forming apparatus in which the manual sheet stacking member is detachable or foldable to reduce the size of the apparatus.

For example, as is apparent from FIG. 18, it is assumed that the manual feed tray 81 is removed from the apparatus main body in a state where the guide member 82a is at the position indicated by the solid line. By doing so, the lever 86 is rotated to a position (not shown) by the spring 88. When the manual feed tray 81 is attached to the apparatus main body again, even if the guide member 82a is not located at the initial position (solid line) and is located at another position 82a '(dotted line), the manual feed tray 81 is attached to the apparatus main body. Then, the abutment portion 85 of the guide member 82a engages with the lever 86, so that the lever 86 stops at the position indicated by the dotted line. In other words, there is no need for the user to adjust the position of the engagement between the regulating member and the lever and the setting of the detecting means, etc., and the size of the sheet can be detected simply by attaching the regulating member and the lever without fail. It is convenient because it can be set up in a possible state. This is the same even when the manual sheet stacking member is configured to be foldable.

Further, since the detecting means is a rotary volume, the resistance value changes steplessly in accordance with a change in the rotation amount (rotation angle) of the rotary shaft. Thus, the size of the sheet can be detected in a stepless manner. It is also possible to use sheets of various sizes.

Therefore, the present invention is effective in improving the operability of a user in an image forming apparatus in which a manual sheet stacking member is made detachable or foldable for downsizing of the apparatus.

Although the present embodiment has been described as a so-called center-based image forming apparatus, it goes without saying that the same effect can be obtained even if this is a one-sided reference.

[Brief description of the drawings]

FIG. 1 is a cross-sectional plan view (a cross-sectional view taken along the line DD in FIG. 3) showing an embodiment of a sheet size detecting device according to the first invention.

FIG. 2 is a plan view of the same (viewed in the direction of arrow C in FIG. 3).

FIG. 3 is a vertical sectional side view of the same.

FIG. 4 is a sectional view taken along line EE of FIG. 2;

FIG. 5 is a vertical sectional side view showing another embodiment of the slide volume unit.

FIG. 6 is a plan view of a sheet size detecting device according to a conventional technique 1;

FIG. 7 is a plan view of a combined top portion of the sheet size detecting device according to the second invention.

FIG. 8 is a plan view of the side regulating member.

FIG. 9 is a plan view of the sheet size detecting device.

FIG. 10 is a perspective view of an image forming apparatus to which the sheet size detecting device is applied.

FIG. 11 is a plan view of a combination piece according to another embodiment 1 of the second invention.

FIG. 12 is a plan view of a coupling piece according to another embodiment 2 of the second invention.

FIG. 13 is a plan view of a combination piece according to Embodiment 3 of the second invention.

FIG. 14 is a plan view of a combination piece according to Embodiment 4 of the second invention.

FIG. 15 is a plan view of a sheet size detection device according to a conventional technique 2.

FIG. 16 is an operation diagram of the combined top section.

FIG. 17 is a vertical side view of the image forming apparatus according to the third invention.

FIG. 18 is a plan view of a sheet feed tray of the image forming apparatus according to the third embodiment.

FIG. 19 is a cross-sectional plan view of a conventional image forming apparatus ((a)).
Figure), side view (Figure (b)).

[Explanation of symbols]

S Sheet 2 Paper feed tray 3 Paper feed roller (paper feed means) 15 Sheet regulating member 16 Rack plate 17 Pulley gear 17A Pulley gear gear (synchronous gear) 17B Pulley gear pulley 21 Lever 20 Sheet size detection device (sheet size detection) Means) 23 Flexible belt 41 Side regulation member 45 Belt 46 Combined piece 47 Slide volume (movement amount detection means) 61, 62 Paper feed tray x Machine body 81 Manual feed tray 82a, 82b Guide member (regulation member) 87 Rotation volume ( Moving amount detecting means)

Continuation of the front page (56) References JP-A-62-46822 (JP, A) JP-A-63-123725 (JP, A) JP-A-62-63245 (JP, U) (58) Fields investigated (Int) .Cl. ⁷ , DB name) B65H 1/00-3/68

Claims (7)

(57) [Claims] 1. A sheet feeding tray capable of stacking a plurality of sheets, sheet feeding means for sequentially feeding sheets on the sheet feeding tray one by one, and a sheet feeding direction on the sheet feeding tray. And a sheet size detecting means for detecting a sheet size in a direction orthogonal to the sheet feeder, wherein a pair of sheets for regulating a position in a direction orthogonal to a sheet feeding direction on the sheet feed tray is provided. A regulating member, a synchronous gear meshing with a rack fixed to the sheet regulating member for synchronizing the movement of each sheet regulating member, a pulley provided integrally with the synchronous gear, and a winding wound around the pulley. And a belt to which a lever of the sheet size detecting means is fixed. 2. The sheet size detecting device according to claim 1, wherein said sheet size detecting means is a slide volume. 3. A sheet feed tray and a side regulating member for a sheet on the sheet feeding tray. The position of the side regulating member is detected by a movement amount detecting means, so that the sheet is stacked on the sheet feeding tray. In the sheet size detection device for determining the size of the sheet material, a belt fed by the movement of the side regulating member, the movement amount detection means and a coupling piece held by the belt, one end of which is linked to the movement amount detection means, A sheet size detecting device, comprising: a joint piece held at two or more points separated from each other on at least one side of the belt. 4. A paper feed tray and a side regulating member for a sheet on the paper feeding tray, and by detecting a position of the side regulating member, a size of a sheet material stacked on the paper feeding tray is detected. A belt fed by the movement of the side regulating member, a movement amount conversion detecting means, and a connecting piece held on the belt and having one end linked to the detecting means. Is a sheet size detection device that is guided at at least two points separated in the movement direction. 5. A pair of regulating members for regulating the position of a manually inserted sheet in the width direction, at least one of the pair of regulating members is movably provided, and the manually inserted sheet is stacked and stored between the regulating members. A manual sheet stacking member provided detachably or foldably on the forming apparatus main body; and a detecting means provided on the image forming apparatus main body for detecting a movement amount of the restricting member. An image forming apparatus, comprising: a lever disposed to engage and rotate with the movement of the regulating member; and a detection unit that detects a change in the rotation angle of the lever. 6. An image forming apparatus according to claim 5, wherein said lever of said detecting means is given a rotational moment in a fixed direction by an elastic member. 7. The image forming apparatus according to claim 5, wherein the detection unit of the detection unit is a rotary volume whose resistance value changes according to a change in a rotation angle of the lever.