JPH1053348A - Sheet feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent careless touching to the parts not related with but touch only to the necessary parts during treating of jams or maintenance in the sheet feeder for the image forming device. SOLUTION: In a sheet feeder A comprising a feeder roller 3, a pick up roller 2 for moving up and down to touch and untouch with sheets which is supported by a pick up roller 5, and a box body 1 covering these from upper part, a cover 6 covering both sides of the feed roller 3 and the pick up roller 2 from the lower side is provided, and when the pick up roller 2 ascends and separated from the sheets, the cover 6 ascends and formes an empty space surrounded by the cover body 1 and the cover 6 so that the paper end filler or other parts can be protected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder,
In particular, the present invention relates to a sheet feeding device of an image forming apparatus that can easily perform maintenance work and prevent damage to components.

[0002]

2. Description of the Related Art As a sheet feeding device of an image forming apparatus, for example, a sheet feeding device described in Japanese Patent Application Laid-Open No. 6-171786 is known. This paper feeder includes a pickup roller,
It has a feed roller, a separate roller, etc., and is provided with a shaft and a gear for driving these, a guide plate for raising and lowering the pickup roller, and the like. Further, a paper end filler for detecting that paper to be fed has run out, a photo interrupter for detecting its height, and the like are also provided.

However, in the above conventional example, not only the rollers such as the pick-up roller, the feed roller, and the separate roller, but also the shafts, gears, and guide plates disposed close to the shafts for driving these rollers. , Paper end filler,
Since various components such as a photo interrupter are also arranged in an exposed state, there are the following problems. When exchanging rollers, it is sometimes difficult for an operator to identify the roller to be exchanged, or parts may be damaged, deformed, or soiled by carelessly touching other parts.

The above-mentioned paper feeder has a unit structure and can be freely attached to and detached from the image forming apparatus main body. In some cases, the parts are deformed or damaged.

[0005] In particular, the paper end filler is provided in a bare state near the pickup roller, and is made light so as not to increase the transport load on the paper to be contacted. Therefore, it is easy to touch and the strength is weak at the time of roller replacement work, so that careless touching often causes deformation and breakage. further,
Since the paper end filler has a structure protruding from the above-described unit structure, there have been cases where the paper end filler is damaged when the unit is attached or detached or when the unit is stored or transported alone.

On the other hand, although the upper part of the detecting means is also covered with the housing, the lower part is exposed, so that dust such as toner generated in the image forming apparatus easily rises and adheres, causing erroneous detection. . In particular, in an image forming apparatus that has been operated to some extent, toner is accumulated everywhere in the apparatus, and when the unit is attached or detached or when the image forming apparatus is moved, the toner falls and enters the inside of the detecting means. This could lead to false detection.

An object of the present invention is to solve the above problems. Specifically, in a paper feeding apparatus, only necessary parts are touched at the time of jam clearance or maintenance, and careless parts are carelessly provided. It is an object of the present invention to provide a sheet feeding device capable of preventing touch.

Another object of the present invention is to provide a paper feeder in which the paper end filler is hardly damaged, in addition to the above objects. Still another object of the present invention is to provide a sheet feeding device capable of preventing erroneous detection of a detecting unit such as a photo interrupter.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a feed roller, a pickup roller supported by a pickup arm and moved up and down so as to come in contact with and separate from a sheet, and a casing for covering these from above. In the paper feeder provided with the above, the pickup arm is provided with a cover that covers the side portions of the feed roller and the pickup roller from below, and when the pickup roller is lifted and separated from the paper, the cover is raised. It is characterized in that a substantially closed space is formed by the housing and the cover.

Further, the paper feeder has a paper end filler, the paper end filler is supported between the housing and the cover, and the cover is raised to form a space in which the housing and the cover are substantially closed. Then, the paper end filler may be configured to be accommodated in the space other than the front end portion.

[0011] The paper end filler may have a detecting means for detecting the height of the paper end filler at a supporting end thereof.

Further, the paper feeding device is provided in the image forming apparatus, and the image forming apparatus is provided with a cover operating means for raising and lowering the cover. The image forming apparatus has a detachable paper tray. By being attached and detached,
The cover operating means may be configured to raise and lower the cover, or the cover may be configured to be a guide plate for guiding the conveyance of the sheet.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of the sheet feeding device of the present invention, and FIG. 2 is a sectional view taken along line BB of FIG. The paper feeder A shown in these figures is detachably attached to an image forming apparatus (not shown) as a paper feed unit, and includes a pickup roller 2, a feed roller 3, and a separate roller 4 in a box-shaped housing 1. I have.

The pick-up arm 5 is supported on a shaft 3a of the feed roller 3, and the pick-up arm 5 is rotatable about the shaft 3a. When the pick-up arm 5 turns, the pick-up roller 2 is shown by a solid line in FIG. The user can move to the position and the position indicated by the virtual line. The pickup roller 2 is driven by the gear 7 from the feed roller 3.

The operation of these rollers in the sheet feeding device A will be briefly described as follows. When feeding the paper, the pickup roller 2 is at the position shown in FIG. 2 (the imaginary line in FIG. 1), contacts the uppermost paper of the paper 9 stacked in the paper feed tray 8, and rotates counterclockwise. To feed the paper toward the feed roller 3.

The sheet that has reached the feed roller 3 is sandwiched between the feed roller 3 and the separate roller 4 and advances rightward in the figure by the feed roller 3 rotating counterclockwise. At this time, the separate roller 4 also rotates counterclockwise,
When two or more sheets are stacked, the lower sheet is pushed back to the left in the drawing so that only the top sheet is fed.

The present invention is characterized in that the cover 6 is formed integrally with the pickup arm 5. The cover 6 covers the lower side of the shaft 3a of the feed roller 3 at the side of the pickup roller and the feed roller, that is, on the left side of the pickup roller and the feed roller 3 in FIG. 1, and prevents dust rising from below. Things. The cover 6 also serves as a guide plate for guiding the sheet from the pickup roller to the feed roller.

In the space surrounded by the cover 6 and the housing 1, in addition to the shaft 3a, a paper end filler 10 for detecting that the stacked paper has been used up and gone, and a paper end filler 10 for the paper end filler 10. Detecting means 1 for detecting height
1 mag is stored.

The paper end filler 10 is a lever in the shape of a square with an enlarged portion 10a at its tip, and is rotatable about a shaft 10b. The shaft 10b is supported by a bracket 10c fixed to the housing 1, and the bracket 10c
Is also fixed with a detecting means 11 for detecting the height of the paper end filler 10.

The detecting means 11 uses a photo interrupter, in which a light emitter and a light receiver are set. When the paper runs out and the enlarged portion 10a at the end of the paper end filler 10 is lowered, the paper is interrupted. The rear end 10d of the end filler 10 enters between the light emitting device and the light receiving device and shuts off light, so that it is possible to detect that the paper has run out.

As shown in FIG. 5, in the embodiment of the present invention,
The cover 6 and the pickup arm 5 operate in conjunction with the attachment / detachment of the paper feed tray 8. As shown in FIG. 1, a cover operating means 12 is provided at the lower left of the sheet feeding device. As shown in FIG. 5A, the cover operating means 12 is an L-shaped lever as a whole, and has a rotation shaft 12a at a corner thereof. Tip 12 of short side of cover operating means 12
b has a tension spring 13 and the cover operating means 12
Is urged counterclockwise. On the long side of the cover operating means 12, a projection 12d is provided upright at the middle, and a tapered surface 12e is formed at the tip of the projection 12d. In addition, a protrusion 12f is formed at the tip of the long side of the cover operation means 12.

When the paper feed tray 8 is not set, the cover operating means 12 is rotated counterclockwise by a tension spring 12 as shown in FIG.
The tapered surface 12e at the tip of d comes into pressure contact with the tapered surface 6a formed at the end of the cover 6 to push the cover 6 upward.

When the paper feed tray 8 is set, FIG.
As shown in FIG. 5C, the paper feed tray 8 pushes the convex portion 12f at the tip of the cover operation means 12, and the cover operation means 12
It moves to the position shown by the virtual line in (a). Then, since the tapered surface 12e is separated from the tapered surface 6a of the lever 6, the lever 6 and the pickup arm 5 descend, and the pickup roller 2 rides on the sheet.

When the paper feeding device is to be removed from the image forming apparatus for jam clearance or maintenance work, the paper feeding tray 8 is removed before the paper feeding device is removed. Then, the pickup arm 5 is raised to the position shown in FIG. 5B, that is, the position shown in FIG. 4, and forms a substantially closed space by the housing 1 and the cover 6, and the total space of the detecting means 11 is included in the space. Thus, most of the paper end filler 10 other than the front end is accommodated, and these can be covered from the outside. Therefore, it is possible to prevent a worker from touching an unnecessary part at the time of jam clearance or roller replacement. Further, at this time, the paper end filler 10 is held by the housing 1 and the cover 6 in a state where only the front end protrudes from the space as shown in FIG.

Further, since the detecting means 11 is completely accommodated in the above-mentioned space, and the space is almost a closed space, it is possible to prevent dust and dirt from entering and being contaminated during maintenance work or the like.

The vertical movement of the pickup arm 5 and the cover 6 is not limited to the configuration of the cover operating means 12 in the embodiment of the present invention, but may be another configuration such as a configuration using a solenoid. is there. It is desirable that the pickup arm 5 be configured to cover the gear portion of the pickup roller 2, the gear 7, and the gear portion of the feed roller 3.

[0027]

According to the present invention as described above,
In a paper feeder comprising a feed roller, a pickup roller supported by the pickup arm and moving up and down to contact and separate the sheet, and a housing for covering these from above, the pickup arm includes the feed roller and the pickup roller. A cover is provided to cover the side from below, and when the pickup roller rises and separates from the paper, the cover is raised to form a substantially closed space between the housing and the cover. During maintenance work, you will not accidentally touch extraneous parts,
It is possible to prevent the parts from being stained or damaged.

When the cover is raised to form a space in which the housing and the cover are substantially closed, if the space other than the tip of the paper end filler is accommodated in the space,
Most of the light and weakly formed paper end filler is protected between the housing and the cover, and is less likely to be damaged.

If the detecting means is provided at the supporting end of the paper end filler, this detecting means is also accommodated in the space formed by the housing and the cover, and is erroneously detected by dirt or dust from the outside. Can be prevented.

The paper feeder is provided in the image forming apparatus, and the operating means for raising and lowering the cover is provided. The image forming apparatus has a detachable paper tray, and the paper tray is detached from the image forming apparatus. In this state, if the operation means raises the cover to form a substantially closed space between the housing and the cover, the inside of the space can be reliably protected at the time of jam clearance or maintenance. If the cover also serves as a guide plate, it is not necessary to have a separate component for guiding the paper, and the apparatus can be made compact and low in cost.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an appearance of a sheet feeding device according to the present invention.

FIG. 2 is a sectional view taken along line BB of FIG.

FIG. 3 is a sectional view taken along line CC of FIG. 1;

FIG. 4 is a view showing a state in which a cover is raised in FIG. 3;

FIG. 5 is a diagram showing a cover operation means and its operation, and FIG.
Is a top view of the cover operating means, (b) is a diagram showing the relationship between the cover operating means and the cover in a state where the paper feed tray is removed, and (c) is a view showing the cover operating means and the cover in a state where the paper feed tray is mounted. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Pickup roller 3 Feed roller 4 Separate roller 5 Pickup arm 6 Cover 8 Paper feed tray 9 Paper 10 Paper end filler 11 Detecting means 12 Cover operating means

Claims (5)

[Claims] 1. A sheet feeder comprising: a feed roller; a pickup roller supported by a pickup arm, which moves up and down so as to come into contact with and separate from a sheet; and a housing that covers the pickup roller from above. A cover is provided to cover the side of the roller and the pickup roller from below, and when the pickup roller rises and separates from the paper, the cover rises to form a substantially closed space between the housing and the cover. Paper feeder. 2. The paper feeder has a paper end filler, the paper end filler is supported between the housing and the cover, and the cover rises to form a space in which the housing and the cover are substantially closed. 2. The paper feeding device according to claim 1, wherein the paper end filler is configured to be accommodated in the space except for the leading end of the paper end filler. 3. The paper feeding device according to claim 2, wherein said paper end filler has a detecting means for detecting the height of the paper end filler at a supporting end thereof. 4. The image forming apparatus, wherein the paper feeder is provided in the image forming apparatus, the cover includes a cover operating means for elevating and lowering the cover, and the image forming apparatus has a detachable paper tray. 4. The sheet feeding device according to claim 1, wherein the cover operation unit moves up and down the cover by being attached and detached. 5. The sheet feeding device according to claim 1, wherein the cover is a guide plate for guiding the conveyance of the sheet.