JPH09156800A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To position a chute member provided on a cover side at high precision when a cover is opened and closed. SOLUTION: Chute positioning pins 14 are provided on a cabinet side corresponding with the attaching position of a chute member 8 on a cover 1 side, engaging parts 12 of the chute member 8 are engaged with the chute positioning pins 14, and horizontal and vertical positioning of the chute member 8 in relation to the cabinet is performed. The chute member 8 is energized to the cabinet side by compression springs 13, and the chute positioning pins 14, a pinch roller 11, engaging parts 12 and the compression springs 13 are arranged on the same axis CL perpendicularly intersecting a paper sheet conveying passage R.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for feeding sheets of different sizes from a multi-stage sheet feeding tray loaded in a cabinet and forming an image on each sheet.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a printer in which a multi-stage paper feed tray is loaded in a cabinet, a side wall of the cabinet has an openable / closable cover corresponding to the paper feeding position of each paper feed tray. It is installed. This cover is mainly opened to remove jammed paper (jam paper) when paper jam (jam) occurs on the paper transport path formed between the cabinet and the cover. In that case, if all of the chute parts that form the paper transport path and the paper feed unit parts such as the paper feed members that feed the paper to the image forming unit through the paper transport path are provided on the cabinet side, It may be difficult to remove the jammed paper because a part of the paper feeding unit parts is in the way.

An image forming apparatus capable of easily removing jammed paper is disclosed in Japanese Patent Laid-Open No. 3-267226. In the image forming apparatus described in this publication, as shown in FIG. 3, one paper feed roller 51 is provided on the cabinet 53 side out of a pair of paper feed rollers 51, 52 that feeds paper with a paper sandwiched therebetween. The other paper feed roller 52 is provided on the cover 54 side. Further, the chute member 55 on the cover 54 side is biased to the cabinet 53 side by the spring 56, and the projections 57a and 57 provided on the chute member 55 side.
By pressing b against the chute guide 58 on the cabinet 53 side with the urging force of the spring 56, a paper conveyance path having a predetermined gap is formed between the cabinet 53 and the cover 54. Further, a pin 59 for positioning a chute is provided on the cabinet 53, and a hook portion 60 is formed on the cover 54. By engaging the hook portion 60 with the pin 59, a vertical direction of the chute member 55 with respect to the cabinet 53 can be improved. The position is regulated.

In the image forming apparatus having the above structure, when the cover 54 is opened when a paper jam occurs,
The paper feed roller 52, the chute member 55, and the like are separated from the cabinet 53 integrally with this. As a result, the paper transport path between the cabinet 53 and the cover 54 is opened, and the jammed paper jammed therein can be easily removed. On the other hand, after finishing the jam removal work, the cover 5
4 is closed, first, the hook portion 60 of the chute member 55 engages with the positioning pin 59 on the cabinet 53 side,
Following this, the chute guide 58 on the cabinet 53 side
The projections 57a and 57b of the chute member 55 are brought into contact with each other by a spring force, whereby the chute member 55 is positioned in the horizontal and vertical directions with respect to the cabinet 53.

[0005]

However, in the above-mentioned conventional image forming apparatus, the urging force of the spring 56 for urging the chute member 55 toward the cabinet 53 is almost in the middle of the chute member 55, that is, the projection 57a and the projection 57b.
Since it is configured to act between the two, the spring force cannot be sufficiently exerted up to the engaging portion between the positioning pin 59 and the hook portion 60, which is separated therefrom. Therefore, the engaging force when engaging the hook portion 60 with the positioning pin 59 becomes weak, and it is difficult to smoothly engage the two when the cover 54 is closed. As a countermeasure against this, for example, as shown in FIG.
The outer diameter D of the positioning pin 59 is set to be small with respect to the recess dimension W of 0, and a slight gap (dimensional margin) in the vertical direction
It is also possible to have both of them engaged with each other, but in such a case, the chute member 55 for the cabinet 53 is used.
The position of will vary in the vertical direction. Then, the variation in the vertical position of the chute member 55 appears as a positional fluctuation of the sheet feeding roller 52 as shown in FIG. 4B, and the pressure contact state between the sheet feeding rollers 51 and 52 becomes inappropriate. Another problem arises.

Further, in this type of image forming apparatus, as shown in FIG. 5, a movable detecting piece 63a is extended on a sheet conveying path R formed by a chute guide 61 on the cabinet side and a chute member 62 on the cover side. There is known one provided with a paper detection sensor 63 which is arranged in the projecting position. However, in the related art, since the paper detection sensor 63 is attached to the frame member 64 on the cabinet side, when the cover is opened and the jammed paper is removed, the paper detection sensor 6 is
The movable detection piece 63a of No. 3 remains on the sheet conveyance path R in a form protruding. Therefore, when removing jam,
The jammed paper or the hand may be caught on the movable detection piece 63a, and the paper detection sensor 63 may be damaged.

The present invention has been made to solve the above problems, and a first object of the present invention is to form an image forming apparatus capable of positioning a chute member provided on the cover side with high accuracy when opening and closing the cover. A second object of the present invention is to provide an image forming apparatus capable of reliably preventing damage to the sheet detection sensor during jam removal work.

[0008]

According to the present invention, there is provided a cabinet in which a multi-stage paper feed tray is loaded, and an openable / closable cover attached to a side wall portion of the cabinet corresponding to a paper feed position of the paper feed tray. A chute member attached to the cover to form a paper conveyance path between the cabinet and the cover, a first paper feed member provided in the cabinet for each paper feed tray, and a chute member attached to the paper feed path. In the image forming apparatus including the second sheet feeding member that is pressed against the first sheet feeding member, the chute member is provided on the cabinet side corresponding to the mounting position of the chute member on the cover side, and A chute positioning member that regulates the position in the horizontal and vertical directions, an elastic body that biases the chute member toward the cabinet, and a chute member, An engaging portion that is engaged with the chute positioning member by the urging force of the elastic body, and is located on the same axis line orthogonal to the paper transport path, the chute positioning member, the second paper feeding member, the engaging portion, and the elastic member. The body is arranged.

In the image forming apparatus having the above structure, the chute member is positioned in the horizontal and vertical directions with respect to the cabinet by engaging the engaging portion of the chute member on the cover side with the chute positioning member provided on the cabinet side. Is done. At this time, since the chute positioning member, the second sheet feeding member, the engaging portion, and the elastic body are arranged on the same axis line orthogonal to the paper transport path, when the cover is closed, the chute positioning member on the cabinet side is placed. The urging force of the elastic body directly acts as the engaging force for engaging the engaging portion of the chute member. Therefore,
Even if there is no dimensional allowance between the chute positioning member and the engaging portion, the elastic body can be surely engaged with each other by the urging force.

Further, according to the present invention, a cabinet in which a paper feed tray is loaded, an openable / closable cover attached to a side wall of the cabinet, a sheet conveying path formed between the cabinet and the cover, and the sheet are provided. In an image forming apparatus including a sheet detection sensor in which a movable detection piece is extendedly arranged on a conveyance path, the sheet detection sensor is attached to a cover side.

In the image forming apparatus having the above structure, when the cover is opened when a paper jam occurs on the paper transport path, the paper detection sensor is separated (retracted) from the cabinet together with the cover. Therefore, it is possible to easily remove the jammed paper without hooking the jammed paper or the hand with the paper detection sensor.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1A and 1B are views for explaining an embodiment of an image forming apparatus according to the present invention, in which FIG. 1A is a plan view of an essential part thereof, and FIG. 1B is a side view of the essential part thereof. In FIG. 1, a cover 1 is attached to a side wall portion of a cabinet (not shown) so as to be openable and closable by a hinge 2. A cabinet (not shown) is configured so that a multi-stage paper feed tray can be freely drawn out, and the cover 1 is attached to the cabinet in correspondence with the paper feeding position of each paper feed tray.

On the cabinet side, a paper feed roller (first paper feed member) 3 is provided for each paper feed tray. The paper feed roller 3 is attached to the rotary support shaft 4 and is rotationally driven by a drive source such as a motor (not shown). In addition, on the cabinet side, a chute guide 5 that forms a paper transport path is provided. The chute guide 5 may be integrally formed with, for example, a frame member that supports the rotation support shaft 4, or may be separately attached to the frame member.

On the other hand, on the cover 1 side, a pair of left and right support frames 6 having an L-shaped cross section are fixed. The pair of support frames 6 supports the chute member 8 on the inner surface side of the cover 1, and the long piece portion extending from the inner surface of the cover 1 to the cabinet side is provided with two engaging holes with a predetermined gap. 7a and 7b are opened. On the other hand, four support legs 9 extend from the chute member 8 toward the cover 1, and each of the support legs 9 engages with the engagement pin 10.
Through the engaging holes 7a and 7b of the support frame 6. The chute member 8 is for forming a sheet conveying path between the cabinet and the cover 1. In this case, the chute guide 5 on the cabinet side is used as an opposite chute so that the sheet conveying path R is formed therebetween. Has become. Here, of the two engaging holes 7a and 7b formed in the support frame 6, the upper engaging hole 7a is formed in a long hole shape in a direction orthogonal to the sheet conveying path R, whereby the chute member 8 is formed. Can be moved back and forth to the cabinet side.

A pinch roller (second paper feed member) 11 is attached to the upper end of the chute member 8. The pinch roller 11 is rotatably supported by a rotation shaft (not shown) provided on the chute member 8. A rotary shaft (not shown) that supports the pinch roller 11 is supported integrally with the roller so as to be movable back and forth on the cabinet side, and is biased to the cabinet side by a biasing means such as a spring interposed between the roller and the chute member 8. Being energized. The pinch roller 11 is pressed against the paper feed roller 3 on the cabinet side by the urging force of the urging means.

Further, hook-shaped engaging portions 12 are provided at both ends of the chute member 8. This engaging portion 12
Are arranged together with the pinch roller 11 on the same axis line CL that is orthogonal to the paper transport path R. In addition, the compression spring 1 as an elastic body is provided between the chute member 8 and the cover 1.
3 is interposed. The compression spring 13 is arranged on the same axis line CL together with the pinch roller 11 and the engaging portion 12, and biases the chute member 8 to the cabinet side. On the other hand, on the cabinet side, chute positioning pins (chute positioning members) 14 are provided corresponding to the mounting positions of the chute members 8 on the cover 1 side. The chute positioning pin 14 regulates the position of the chute member 8 in the horizontal and vertical directions with respect to the cabinet, and the chute positioning pin 14 is accurately positioned with respect to the paper feed roller 3 and the chute guide 5 provided on the cabinet side. .

Here, the engagement portion 12 provided on the chute member 8 is engaged with the chute positioning pin 14 on the cabinet side by the biasing force of the compression spring 13. That is, in the present embodiment, the chute positioning pin 14 and the pinch roller 1 are arranged on the same axis line CL that is orthogonal to the sheet conveyance path R.
1, the engaging portion 12 and the compression spring 13 are arranged. In this state, the chute member 8 is supported in a so-called floating state in which the engaging portion 12 of the chute member 8 is completely abutted against the chute positioning pin 14 on the cabinet side by the biasing force of the compression spring 13, so that the chute member 8 is supported on the cabinet side. The position of the chute member 8 with respect to is restricted by the chute positioning pin 14.

On the other hand, with respect to the position of the chute positioning pin 14 on the cabinet side, the chute positioning is performed when the cover 1 is closed because the position of the chute positioning pin 14 with respect to the paper feed roller 3 and the chute guide 5 is set with high accuracy as described above. By engaging the engaging portion 12 with the pin 14, the chute member 8 is simultaneously positioned in the horizontal and vertical directions with respect to the cabinet. As a result, the gap of the sheet conveying path R formed between the chute guide 5 on the cabinet side and the chute member 8 on the cover 1 side is properly maintained, and the cover 1 side with respect to the paper feed roller 3 on the cabinet side. The relative position of the pinch roller 11 is also properly maintained.

In the present embodiment, the pin-shaped chute positioning member 14 is provided on the cabinet side, and the hook-shaped engaging portion 12 that engages with the pin-shaped chute positioning member 14 is provided on the chute member 8. Regarding the structure of the engaging portion, for example, the hook shape of the engaging portion 12 has a concave V-shaped cross section, and the V-shaped surface is abutted against the chute positioning member. Any structure may be adopted as long as the member 8 can be positioned with high accuracy. In addition, a hook-shaped chute positioning member may be provided on the cabinet side, and a pin-shaped engaging portion may be provided on the chute member 8 side so that both are engaged.

In the image forming apparatus having the above-described structure, a paper jam occurs on the paper conveyance path R, and when the cover 1 is opened to remove the jammed paper, the chute member 8 is mounted together with the cover 1 on the cabinet. Away from. As a result, the pressure contact state between the paper feed roller 3 and the pinch roller 11 is released, and the engagement state between the chute positioning pin 14 and the engagement portion 12 is released. As a result, the sheet conveyance path R is opened, so that the sheet jammed between the rollers and the chute can be easily removed.

Thereafter, when the cover 1 is closed after the jam removal work is completed, the engaging portion 12 of the chute member 8 tries to engage with the chute positioning pin 14 on the cabinet side in the middle of the process. At this time, since the chute positioning pin 14, the pinch roller 11, the engaging portion 12 and the compression spring 13 are arranged on the same axis line CL that is orthogonal to the sheet conveyance path R, the urging force of the compression spring 13 is the chute. It directly acts as an engaging force for engaging the positioning pin 14 and the engaging portion 12. As a result, the chute positioning pin 14 and the engagement portion 12 can be reliably engaged with each other by the biasing force of the compression spring 13 without providing a dimensional margin between the chute positioning pin 14 and the engagement portion 12 as in the conventional case.

Therefore, even if the cover 1 is repeatedly opened and closed, the chute positioning pin 14 and the engaging portion 12 can be surely engaged with each other each time. It is possible to maintain a uniform gap G between the chutes between the rollers, which requires high accuracy. Further, since the engaging member 12 can be engaged with the chute positioning pin 14 without gaps in the vertical direction, the position of the pinch roller 11 on the cover 1 side with respect to the paper feed roller 3 on the cabinet side is also maintained appropriately and with high accuracy. can do. As a result, the pinch roller 11 on the cover 1 side can always be pressed against the paper feed roller 3 of the cabinet with an appropriate pressure. Further, since the chute member 8 and the engaging portion 12 are engaged with each other, the chute member 8 can be positioned in the horizontal and vertical directions with respect to the cabinet at the same time. The positioning mechanism can be simplified as compared with the case where the means is provided.

Next, an embodiment of the image forming apparatus according to the present invention for the purpose of preventing damage to the sheet detection sensor when the cover is opened to remove the jammed sheet will be described with reference to FIG. In FIG. 2, a paper feed roller 21 is provided on the side of a cabinet (not shown) in which the multi-stage paper feed trays 20 are loaded. A feeding roller 22 is pressed against the uppermost position of the paper P stored in the paper feed tray 20 by an up / down mechanism (not shown). When the feeding roller 22 rotates in the direction of the arrow, the paper P is called in order from the top,
It is fed between the pair of delivery rollers 23. The feeding roller 23 sandwiches the paper P between them, and one roller (retard roller) prevents the paper from being fed in a double manner, and the other roller (feeding roller) feeds the paper P along the upper and lower guide plates 24.

On the other hand, a cover (not shown) is openably and closably attached to the side wall portion of the cabinet having the above-mentioned paper feeding unit, corresponding to the paper feeding position of the paper feeding tray 20. A chute member 26 that forms a sheet conveyance path R between the cover and the chute guide 25 on the cabinet side is attached to the cover. In addition, the chute member 26
A pinch roller 27 is rotatably attached to the paper feed roller 21, and the pinch roller 27 is pressed against the paper feed roller 21 on the cabinet side.

Here, in this embodiment, a paper detection sensor 28 for detecting the presence or absence of the paper P in the paper transport path R is attached to the cover side as a characteristic part thereof. More specifically, the paper detection sensor 28 is attached to the chute member 26 attached to the cover via, for example, a sensor fixing bracket (not shown). The movable detection piece 28a of the paper detection sensor 28 extends from the main body portion toward the paper conveyance path R, and the tip thereof is arranged on the paper conveyance path R. As the fixing means of the paper detection sensor 28 to the chute member 8, various forms such as screw fastening, adhesion method, and locking method with elastic claws can be adopted.

Here, the feeding roller 2 is fed from the paper feed tray 20.
When the paper P called by 2 is sent out on the paper transport path R by the sending-out roller 23, the leading end of the paper comes into contact with the movable detection piece 28a of the paper detection sensor 28 and pushes the movable detection piece 28a as it is. It advances between the paper roller 21 and the pinch roller 27. Further, the sheet fed from the lower sheet feeding unit also comes into contact with the movable detecting piece 28a while passing through the sheet conveying path R, and then advances between the sheet feeding roller 21 and the pinch roller 27.
At this time, since the movable detection piece 28a is displaced by a predetermined amount due to the contact with the paper P, the output signal of the paper detection sensor 28 is changed from on (Hi level) to off (Low level) or off. Switches from to on.
Therefore, by monitoring the output signal of the paper detection sensor 28, the position of the paper P during conveyance can be accurately determined.

On the other hand, when the cover is opened due to a paper jam on the paper transport path R, the paper detection sensor 28 together with the chute member 26 from the paper feeding unit on the cabinet side.
Are separated (evacuated). Therefore, there is no possibility of damaging the paper detection sensor 28 during the jam removal work. As a result, the troublesomeness of maintenance such as the need to carefully remove the jammed paper while paying attention not to catch the jammed paper or the hand on the paper detection sensor 28 is eliminated, and the jammed paper can be removed very easily. Becomes

[0028]

As described above, according to the image forming apparatus of the present invention, by engaging the engaging portion provided on the chute member with the chute positioning member provided on the cabinet side, Since the positioning is performed in the horizontal and vertical directions at the same time, and the chute positioning member, the second paper feeding member, the engaging portion and the elastic body are arranged on the same axis line orthogonal to the paper transport path,
The urging force of the elastic body that urges the chute member toward the cabinet side can be effectively applied as the engaging force that engages the engagement portion of the chute member with the chute positioning member on the cabinet side. Accordingly, when the cover is opened and closed, the engagement portion can be reliably engaged with the chute positioning member, so that the chute member on the cover side can be accurately positioned with respect to the cabinet.

Further, according to the image forming apparatus of the present invention, the paper jam sensor is mounted on the cover side by mounting the paper detection sensor in which the movable detection piece is arranged on the paper conveyance path formed between the cabinet and the cover. When the cover is opened when the above occurs, the paper detection sensor is separated from the cabinet together with the cover. Therefore, during the jam removal work, there is no need to worry about jammed paper or hands being caught on the movable detection piece of the paper detection sensor.
It is possible to reliably prevent damage to the paper detection sensor.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention.

FIG. 2 is a diagram illustrating another embodiment of the present invention.

FIG. 3 is a diagram illustrating a conventional technique.

FIG. 4 is a diagram illustrating a conventional problem.

FIG. 5 is a diagram illustrating another conventional problem.

[Explanation of reference numerals] 1 cover 3 sheet feeding roller (first sheet feeding member) 8 chute member 11 pinch roller (second sheet feeding member) 12 engaging portion 13 compression spring (elastic body) 14 chute positioning pin (chute Positioning member) 28 paper detection sensor 28a movable detection piece R paper transport path

Claims (2)

[Claims] 1. A cabinet in which a multi-stage paper feed tray is loaded, an openable and closable cover attached to a side wall portion of the cabinet corresponding to a paper feeding position of the paper feed tray, the cabinet and the cover. A chute member attached to the cover to form a paper conveyance path between the first and second paper feed trays; a first paper feed member provided in the cabinet for each paper feed tray; An image forming apparatus including a second sheet feeding member that is pressed against the first sheet feeding member on a road, the image forming apparatus being provided on the cabinet side corresponding to a mounting position of the chute member on the cover side, A chute positioning member that regulates the horizontal and vertical positions of the chute member with respect to the cabinet; and the chute member on the cabinet side. And an engaging portion that is provided on the chute member and that is engaged with the chute positioning member by the urging force of the elastic body. The chute is on the same axis orthogonal to the paper transport path. An image forming apparatus comprising a positioning member, the second paper feeding member, the engaging portion, and the elastic body. 2. A cabinet in which a paper feed tray is loaded, an openable / closable cover attached to a side wall of the cabinet, a paper conveyance path formed between the cabinet and the cover, and the paper conveyance. An image forming apparatus comprising: a sheet detection sensor having a movable detection piece extending on a road, wherein the sheet detection sensor is attached to the cover side.