JP2903921B2 - Paper sheet stacking 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 paper sheet stacking apparatus,
In particular, the present invention relates to a sheet stacking device for an electrophotographic recording device.

[0002]

2. Description of the Related Art Conventionally, when printing with an electrophotographic recording apparatus, this type of paper sheet stacking apparatus causes curling of a printing medium after printing due to the type of printing medium and environmental conditions. Print media does not stack well in the stack. For this reason, there has been developed a stack having a function of suppressing stacking disorder due to the effect of curling in the stack portion and improving stackability.

FIG. 2 is a view showing a first example of a conventional sheet stacking apparatus. Referring to FIG. 2, the stack unit 1 has a restraining unit 17 that can be moved and adjusted according to the length of the print medium, and the stacking unit 1 aligns the leading ends of the print medium to be discharged to the stack unit 1 in the discharge direction. The stacking disorder in A is suppressed to improve the stacking property.

FIG. 3 is a view showing a second example of a conventional sheet stacking apparatus. Referring to FIG. 3, by stacking the suppressing means 18 provided in the stack unit 1 in accordance with the length of the print medium, the leading ends thereof are aligned for print media having different lengths, and the stacking in the discharge direction A is performed. The turbulence is suppressed to improve the stackability.

[0005]

The conventional paper sheet stacking apparatus has the following problems, and the printing medium has poor stackability.

First, as shown in FIG. 4, when the print medium 9 has a large amount of curl, the print medium 9 is curled to the stack portion because there is no means for suppressing the curl of the print medium discharged to the stack portion. Emitted and not stacked.

Even when the curl of the print medium 9 is small, the position of the print medium reaching the leading end of the print medium on the stack portion is different between the case where the curl does not occur (FIG. 5) and the case where the curl occurs (FIG. 6). Fluctuates toward the print medium discharge port side a. For this reason, the leading end of the printing medium does not reach the position b of the suppressing means set in accordance with the length of the printing medium on the assumption that no curl occurs, so that the leading end of the printing medium cannot be aligned and stackability cannot be improved. .

[0008] Further, in the case where the stacking portion continues to be discharged exceeding the allowable number of stacking portions, it is impossible to prevent the collapse of the printing medium and the drop of the printing medium from the stacking portion.

Further, when it is necessary to open the upper cover of the printing section due to paper jam inside the printing section when the printing medium is stacked on the stack section, the printing medium stacked on the stack section is removed. If the opening is not made, the stack portion cannot hold the print medium and the print medium drops as shown in FIG. Therefore, at the time of opening the upper cover, it is necessary to remove the print media stacked on the stack unit.

An object of the present invention is to provide a sheet stacking apparatus for an electrophotographic recording apparatus having a good stacking property by providing a means for suppressing curling caused by the type of printing medium and environmental conditions. It is in.

[0011]

According to the present invention, there is provided a paper sheet stacking apparatus for stacking a printing medium discharged from a medium discharge port of a printing means, and a stacking means for stacking the printing medium from a direction perpendicular to the stacking surface of the stacking means. Pressing means for pressing the print medium; holding means for holding the pressing means, having a plane perpendicular to the stacking surface and parallel to the medium discharge port, and capable of holding the pressing means, and printing one end of the printing medium. The other end is fixed to the holding means.
When opening the upper cover of the printing means
Acting on the upper cover of the printing means.
Press the printing medium deposited on the stacking means to the stacking means.
And a spring member for pressing .

[0012]

[0013]

[0014]

[0015]

[0016]

Next, the present invention will be described with reference to the drawings. Referring to FIG. 1 showing a configuration of an embodiment of the present invention,
In the sheet stacking apparatus of this embodiment, the stack unit 1
The printing medium 9 is provided above the printing unit 16 and is connected to the discharge port 2 from which the printing medium 9 printed by the printing unit 16 is discharged.
It is located downstream in the transport direction. The outlet 2 side of the stack surface 3 is at a position lower than the outlet 2. Stopper support 7
Has a plane perpendicular to the stack surface 3 and parallel to the discharge port 2, is movable in the discharge direction of the print medium 9, and holds the stopper tip 6. The stopper tip 6 includes a roller 11 for reducing friction with the print medium 9, a stopper 4, and a spring 8 provided at a connection portion with the stopper support 7. The curl portion 10 of the print medium 9 which is movably mounted and discharged is pressed against the stack surface 3. The sensor 12 is attached to the stopper 4 and detects the amount of displacement of the tip 6 of the stopper. The control unit 13 controls one character stop / restart of the printing unit 16 based on a signal from the sensor 12. The control unit 13
When the sensor 12 detects that the height of the printing media 9 stacked on the stack unit 1 has reached the limit amount, the printing of the printing unit 16 stops one character and the buzzer 5 sounds. Further, when the print medium 9 of the stack unit 1 is removed, the control unit 13 resumes printing. The stopper support 7 is connected to the upper cover 15 of the printing unit 16 by a spring 14, and the upper cover 1
At the time of opening 5, the print medium 9 on the stack unit 1 is strongly pressed against the stack surface 3.

Next, the operation of this embodiment will be described. First, the position of the stopper support 7 is adjusted so that the length from the outlet 2 to the stopper support 7 is equal to the length of the print medium 9 in the transport direction. When printing is started, the printed print medium 9 is discharged from the discharge port 2 to the stack unit 1 with the print surface facing downward. At this time, the stopper tip 6 presses the curled portion 10 generated on the print medium 9 against the stack surface 3 by the pressure of the spring 8. As a result, the print medium 9 is normally discharged to the stack unit 1 while the curl is extended, and the leading end of the print medium 9 abuts against the stopper support unit 3 and is stacked. The printing medium 9 printed during continuous printing is the stack surface 3
Is stopped, the stopper supporting portion 7 prevents the printed print medium 9 from being pushed out of the stack surface 3 due to friction between the printed print medium 9 already stacked on the stack surface 3. Further, the strength of the spring 8 is a strength that does not hinder the ejection of the print medium 9, and
The print medium 9 is discharged to the stack unit 1 without receiving pressure or frictional resistance that hinders discharge by the rollers 11 provided in the stack unit 1. When a large amount of continuous printing is performed, the stacking amount of the printing media 9 in the stack unit 1 gradually increases, and the stopper tip 6 is lifted upward accordingly. When the stacking amount of the print media 9 reaches the limit, the sensor 12 detects the limit. The control unit 13 that has received the detection of the sensor 12 temporarily stops printing and sounds the buzzer 5. When the print medium 9 is removed from the stack unit 1, the stopper tip 6 returns to the fixed position from the stack limit position, and the sensor 12 does not detect the limit of the stack amount.
3 resumes the paused printing and stops the buzzer sound.

When the upper cover 15 is opened for paper jam treatment inside the printing section 16, the spring 1 connected to the stopper support section 7 and the upper cover 15 of the printing section 16.
By strongly pressing the print medium 9 on the stack unit 1 against the stack surface 3 at 4, the print medium 9 is prevented from falling from the stack unit 1.

[0019]

As described above, according to the present invention,
Stacking means for stacking the print medium discharged from the medium outlet of the printing means, pressing means for pressing the print medium from a direction perpendicular to the stacking surface of the stacking means, and parallel to the medium outlet and perpendicular to the stacking surface With a holding means having a flat surface and movable in the printing medium discharge direction and holding the pressing means, curling caused by the type of printing medium and environmental conditions can be suppressed, and good stacking properties can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a first conventional example.

FIG. 3 is a diagram showing a second conventional example.

FIG. 4 is a diagram illustrating a state in which a conventional print medium has a large amount of curl.

FIG. 5 is a diagram illustrating a print medium leading end position on a stack unit when curling does not occur.

FIG. 6 is a diagram illustrating a print medium leading end position on a stack unit when curling occurs.

FIG. 7 is a diagram showing a state in which the stack unit of the conventional example drops when the upper cover is opened because the stack unit cannot hold the print medium and cannot fall.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stack part 2 Discharge port 3 Stack surface 4 Stopper 5 Buzzer 6 Stopper tip part 7 Stopper support part 8 Spring 9 Print medium 10 Curl part 11 Roller 12 Sensor 13 Control part 14 Spring 15 Upper cover 16 Print part

Claims (1)

(57) [Claims] An accumulating means for accumulating a print medium discharged from a medium discharge port of a printing means; a pressing means for pressing the print medium from a direction perpendicular to the accumulating surface of the accumulating means; Holding means for holding the pressing means, the holding means being perpendicular to the medium discharge port and movable in the print medium discharge direction, and having one end held by the printing means and the other end held by the printing means;
Holding the upper cover of the printing means fixed to the holding means.
Only on the top cover of the printing means.
The printing medium deposited on the depositing means
And a spring member for pressing the stacking means .