JPH0656305A - Paper feed tray - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a paper feed tray device capable of preventing erroneous detection of paper end. [Structure] Paper detection means 11 for detecting the presence / absence of paper on a paper feed tray 9 and a calling roller 3 for abutting the topmost paper
Upper limit detecting means 3-2 for detecting the upper limit position of the paper feed tray 9 by the movement of the lower limit, lower limit detecting means 9-2 for detecting the lower limit position of the paper feed tray 9 for replenishing the paper, and upper limit position and lower limit position. Elevating means 6-1 for elevating the paper feed tray 9 between
In the paper feed tray device having the above, the paper detection means 11 is provided between the pressing members 14a, 15, 16 for pressing the uppermost paper and the calling roller 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed tray device applied to an image forming apparatus, and more particularly to a paper feed tray device having tray elevating means.

[0002]

2. Description of the Related Art FIG. 13 is a schematic front view of a general paper feed tray device, FIG. 14 is a perspective view showing the mechanism of an upper limit detector, and FIG.
5 is a perspective view showing the mechanism of the lower limit detector, and FIG. 16 is a perspective view showing the bottom plate raising mechanism.

In this paper feeding device, the tray bottom plate (paper feeding tray) 9 on which the paper P is stacked is at the lower limit position for supplying the paper P (the lower limit detection plate 9-1 attached to the tray bottom plate 9 is shown in FIG. 15). When the lower limit detection sensor 9-2 is cut off, the motor is turned off and stops) and the position where the uppermost sheet P contacts the calling roller 3 is moved up and down. The tray bottom plate 9 has a paper detection filter 10, and when the paper P is present, it is pushed as shown in FIG. 13 and the paper detection sensor 11 is not shut off. When there is no paper P, the paper detection filter 10 projects above the tray bottom plate 9. At this time, the sheet detection filter 10 shuts off the sheet detection sensor 11 and does not raise the tray bottom plate 9. Alternatively, when the paper P is exhausted, the tray bottom plate 9 is lowered.

The tray elevating means includes six pulleys 5, a drive pulley 6 and a drive pulley 6, which are rotatably mounted on a side plate 4 (only the back side is shown in the drawing, but the side plates are on the front and rear sides). It is composed of a tray motor 6-1 to be driven and a drive wire 7 stretched around each pulley 5 thereof. When the tray motor 6-1 on the back side of the tray is rotated, the drive wire 7 is driven in the direction of the arrow when the tray motor 6-1 is raised, and the front and rear bottom plate supporting brackets 9-3 are raised (the bracket 9-3 is attached to the tray bottom plate 9). Installed). A disk 6-2 and a remaining amount detection sensor 6-3 are provided in the vicinity of the tray motor 6-1, and the number of pulses from the start of raising the tray to the stop when the rise is detected is counted and the remaining amount of paper is displayed. You can The elevating guide 13 guides the shaft crimped to the bracket 9-3 (see FIG. 16, and FIG. 13 is a view seen from the direction A in FIG. 16). Reference numeral 8 is an end fence, and 13 is a lifting guide.

Next, the upper limit detection mechanism will be described with reference to FIG.

When the tray bottom plate 9 rises and the calling roller 3 is lifted by the upper surface of the sheet P, the shielding plate 14 shuts off the upper limit detection sensor 3-2 and the tray motor 6-1 is turned off. In addition, when the upper limit detection sensor 3-2 is opened by making a copy and lowering the upper surface of the paper P, the tray motor 6 again
-1 is turned on and the paper P is raised.

When the paper P is fed, a paper feed clutch (not shown) is turned on by a paper feed signal, the paper feed roller shaft 1-1 is rotated, the paper feed roller 1 is rotated, and the gear is rotated. The calling roller 3 is rotated by the system, and the paper P is sent to the transport unit. When the front end of the paper P is fed by a certain amount, the pick-up solenoid 3-1 is turned on, and the calling roller 3 is lifted to reduce the load on the paper P (when the pick-up solenoid 3-1 is turned on, the pick-up solenoid 3-1 is lifted in the direction of the arrow). ). Calling roller 3
The pressure is determined by the spring 3-3.

[0008]

In such a paper feed tray device, when the number of papers stacked on the paper feed tray becomes small, the paper detection fil- ter pushes up the paper and displays the paper end even if there is paper. May appear. In particular,
The tendency is strong for paper that is curled, thin, or small in size.

Further, the abnormal rise of the paper feed tray is apt to occur due to mishandling by the user who uses the paper tray. When replenishing the paper, if the paper does not move to the set position when set, keep the set paper away from the paper. (If you set the tray in this state, the paper may shift due to inertia. ). If the tray rises with the paper misaligned (normally, the upper limit detector detects the paper and stops it), the upper limit detection sensor cannot detect it, and the tray rises further, and eventually drive parts etc. are destroyed. Sometimes.

In order to prevent damage, load detection of the motor,
The serviceman call is displayed depending on the time, etc., but if the drive parts are destroyed, it is necessary to replace the entire tray.

The present invention has been made based on such a background, and an object thereof is to provide a paper feed tray device capable of preventing erroneous detection of a paper end.

[0012]

The above object is to detect the presence or absence of paper on the paper feed tray, and to detect the upper limit position of the paper feed tray by the movement of the calling roller that abuts the uppermost paper. In a paper feed tray device including an upper limit detection means, a lower limit detection means for detecting a lower limit position of a paper feed tray for replenishing paper, and an elevating means for elevating the paper feed tray between an upper limit position and a lower limit position, This is achieved by the first means in which a pressing member for pressing the uppermost paper is provided and the paper detecting means is arranged between the pressing member and the calling roller.

The above object is also achieved in the first means by the second means in which the pressing member is above the calling roller.

Further, the above-mentioned object is, in the first means, that the pressing member is formed by extending a part of the shielding plate to which the calling roller is attached, or by the pressing roller attached to the shielding plate. This is achieved by the third means configured.

Further, the above object is achieved by the fourth means in the first means, wherein the pressing member extends upstream from the calling roller.

The above object is also achieved by a fifth means in which the pressing member is provided with an erroneous set detection means in the first means.

The above object can be achieved by the sixth means in the fifth means, which stops the rising of the paper feed tray and gives a warning when only the erroneous set detection means detects.

[0018]

In the first means, since the paper detecting means is provided between the calling roller and the pressing member, erroneous detection (end display even though there is paper) is prevented even when the number of paper is small.

In the second means, the pressing member is located above the calling roller so that the pressing member does not apply pressure to the paper even when the diameter of the calling roller is reduced due to wear of the calling roller. (When the pressing member applies pressure to the paper, pressure is applied to the calling roller and the pressing member, causing skew and non-feeding. To prevent this, the pressing member needs to be above the calling roller).

In the third means, a part of the shielding plate is extended as a pressing member or a pressing roller is added, so that the structure is simple and the performance is surely improved.

According to the fourth means, even if the paper is misaligned, the driving parts can be surely stopped without being destroyed. Further, extending the pressing member to the upstream side of the calling roller can be easily solved by forming the pressing member by making a part of the shielding plate long.

In the fifth means, the paper feed tray can be surely stopped even when the paper is misaligned due to erroneous set detection, and the drive parts can be prevented from being destroyed.

According to the sixth means, it is possible to reset the paper by issuing a warning and calling attention by false detection of the set, and it is possible to prevent a paper feed jam.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. It should be noted that parts that are the same as or can be regarded as the same as those in the conventional example are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a perspective view of an upper limit detector of the paper feed tray apparatus according to the first embodiment, FIG. 2 is the same as the top view, and FIG. 3 is the same.
It is a front view.

Shielding plate 14 to which the calling roller 3 is attached
A pressing roller 15 is added as a pressing member. As shown in FIG. 3, the pressing roller 15 is slightly above the calling roller 3 (the pressing roller 15 is larger than the calling roller 3 in distance from the tray bottom plate 9).
This is because even if the diameter of the calling roller 3 is reduced due to wear or the like, the pressing roller 15 presses the sheet P to prevent the occurrence of crevices. The calling roller 3 may rotate freely.

A sheet detecting filter 10 is provided between the pressing roller 15 and the calling roller 3, and the calling roller 3 is provided.
Since the paper detection filer 10 is provided between the pressing roller 15 and the pressing roller 15, it is possible to prevent erroneous detection (end display even though there are papers) even when the number of papers is small.

FIG. 4 is a perspective view of the upper limit detector of the paper feed tray apparatus according to the second embodiment, and FIG. 5 is a front view of the same.

Shielding plate 14 to which the calling roller 3 is attached
A part of the above is extended and a pressing portion 14a is formed below. In the figure, the sheet P is pressed by the edge of the sheet metal. A separate member (resin) or the like may be attached instead of the sheet metal. Similar to the first embodiment, there is a pressing portion 14a slightly above the calling roller 3 (see FIG. 5).

In the first and second embodiments, the pressing member is located at substantially the same position as the calling roller 3 (see FIG. 2).

FIG. 6 is a front view of a general upper limit detector shown in comparison with the first and second embodiments of FIGS. 3 and 5, but the sheet detecting filter 10 pushes up the sheet P. , The paper end is in the false detection state.

FIG. 7 is a perspective view of the upper limit detector of the paper feed tray apparatus according to the third embodiment, and FIG. 8 is a top view of the same. FIG. 9 is a perspective view of the upper limit detector of the paper feed tray device according to the modification of the third embodiment.

In these embodiments, the shielding plate 14 extends on the upstream side of the calling roller 3 (on the side opposite to the direction in which the sheet is conveyed) to form the pressing portion 14a. In addition, FIG.
In the third embodiment of FIG. 8, a pressing roller 15 is provided in addition to the pressing portion 14a.

When the sheet P is not properly set as shown in FIG. 10 or when the sheet P is moved due to a large impact when the tray bottom plate 9 is set, the tray bottom plate 9 can be contacted by the calling roller 3. Stops when the upper limit is detected, but if not contacted, the tray bottom plate 9 further rises and may be destroyed in the worst case. In order to avoid this, if the shielding plate 14 is extended to the upstream side of the calling roller 3, even when the paper P is not normal, it can be stopped without being destroyed.

In the modification of the third embodiment shown in FIG. 9, the pressing roller 15 is not provided.

FIG. 11 is a perspective view of the upper limit detection mechanism of the paper feed tray device according to the fourth embodiment, and FIG. 12 is a front view of the same.

In this embodiment, the tip end of the pressing arm 16 which is independent of the shielding plate 14 is provided so as to extend to the upstream side of the calling roller 3. The pressing arm 16 is rotatable, and pressure is applied to the sheet P by the torsion spring 16-2.

As a stopper of the pressing arm 16, there is a bent portion 14b at the lower end of the shielding plate 14, and the pressing arm 16 is brought into contact with the bent portion 14b to determine the position of the pressing arm 16 (the center of rotation of the pressing arm 16). And the rotation center of the shielding plate 14 is the same).

When the paper set is bad as shown in FIG. 10, it cannot be detected by the calling roller 3, but the pressing arm 16
Can be detected by raising the tray bottom plate 9. Here, the pressing arm 16 is pushed up, but the spring 3-3 is set so that the shield plate 14 is not pushed up. When the paper set is bad, the pressing arm 16 is pushed up to shut off only the erroneous set detection sensor 16-1. At this time, a warning and a warning may be displayed. Then, since the tray motor 6-1 stops, the tray bottom plate 9 stops rising.

When only the erroneous set detecting means detects the sheet, it is more preferable to lower the tray bottom plate 9 to display a warning and a warning display because the paper P in the tray bottom plate 9 can be immediately reset.

If the paper set is normal, both the shield plate 14 and the pressing arm 16 shield the sensors 3-2 and 16-1. At this time, it is determined to be normal. In this case, the paper can be fed.

[0042]

According to the first aspect of the present invention, since the sheet detecting means is provided between the calling roller and the pressing member, even if the number of sheets is small, an erroneous detection is made (there is an end indication even though there are sheets). Can be prevented.

According to the second aspect of the present invention, since the pressing member is above the calling roller, the pressing member does not apply pressure to the sheet even when the diameter of the calling roller is reduced due to wear of the calling roller.

According to the third aspect of the present invention, by extending a part of the shielding plate as a pressing member or adding a pressing roller, the structure is simple and the performance can be surely improved.

According to the fourth aspect of the present invention, even when the paper is misaligned, the driving parts can be surely stopped without being destroyed. Further, extending the pressing member to the upstream side of the calling roller can be easily solved by forming the pressing member by making a part of the shielding plate long.

According to the fifth aspect of the present invention, even if the sheets are misaligned due to erroneous set detection, the paper feed tray can be stopped without fail, and the drive parts can be prevented from being destroyed.

According to the sixth aspect of the present invention, it is possible to reset the paper by issuing a warning and calling attention by false detection of the set, and it is possible to prevent a paper feed jam.

[Brief description of drawings]

FIG. 1 is a perspective view of an upper limit detection unit of a paper feed tray device according to a first embodiment of the present invention.

FIG. 2 is a top view of an upper limit detector of the paper feed tray device according to the first embodiment of the present invention.

FIG. 3 is a front view of an upper limit detection unit of the paper feed tray device according to the first exemplary embodiment of the present invention.

FIG. 4 is a perspective view of an upper limit detection unit of a paper feed tray device according to a second embodiment of the present invention.

FIG. 5 is a front view of an upper limit detector of a paper feed tray device according to a second embodiment of the present invention.

FIG. 6 is a front view of a general upper limit detector.

FIG. 7 is a perspective view of an upper limit detection unit of a paper feed tray device according to a third embodiment of the present invention.

FIG. 8 is a top view of an upper limit detection unit of the paper feed tray device according to the third embodiment of the present invention.

FIG. 9 is a perspective view of an upper limit detection unit of a paper feed tray device according to a modification of the third embodiment.

FIG. 10 is a configuration diagram showing a state in which the set state of paper is bad.

FIG. 11 is a perspective view of an upper limit detection unit of the paper feed tray device according to the third embodiment of the present invention.

FIG. 12 is a front view of an upper limit detection unit of a paper feed tray device according to a third embodiment of the present invention.

FIG. 13 is a schematic front view of a general paper feed tray device.

FIG. 14 is a perspective view showing a mechanism of an upper limit detector.

FIG. 15 is a perspective view showing a mechanism of a lower limit detection unit.

FIG. 16 is a perspective view showing a bottom plate lifting mechanism.

[Explanation of symbols]

 1 Feeding Roller 2 Reverse Rotating Roller 3 Calling Roller 3-2 Upper Limit Detection Sensor (Upper Limit Detection Means) 6-1 Tray Motor (Up / Down Means) 9 Tray Bottom Plate (Feeding Tray) 9-2 Lower Limit Detection Sensor (Lower Limit Detection Means) 11 Paper detection sensor (paper detection means) 14a Pressing part (pressing member) 15 Pressing roller (pressing member) 16 Pressing arm (pressing member)

Claims (6)

[Claims] 1. A paper detection means for detecting the presence or absence of paper on the paper feed tray, an upper limit detection means for detecting the upper limit position of the paper feed tray by the movement of a calling roller contacting the uppermost paper, and replenishing paper. In order to ensure the lower limit position of the paper feed tray, in the paper feed tray device equipped with the lower limit detection means and the elevating means for elevating the paper feed tray between the upper limit position and the lower limit position, a pressing member for pressing the topmost paper is provided. A sheet feeding tray device, wherein the sheet detecting means is provided between the pressing member and the calling roller. 2. The sheet feeding tray device according to claim 1, wherein the pressing member is located above the calling roller. 3. The pressing member according to claim 1, wherein the pressing member is formed by extending a part of a shielding plate to which the calling roller is attached, or is constituted by a pressing roller attached to the shielding plate. Paper feed tray device characterized by. 4. The sheet feeding tray device according to claim 1, wherein the pressing member extends upstream from the calling roller. 5. The sheet feeding tray device according to claim 1, wherein the pressing member is provided with erroneous set detection means. 6. The paper feed tray device according to claim 5, wherein when only the erroneous set detection means detects, the rising of the paper feed tray is stopped and a warning is issued.