JP3736712B2 - Paper discharge device and electrophotographic device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper discharge device that stacks and stores sheets one by one on a stacker table provided so as to be movable up and down.
[0002]
[Prior art]
A paper discharge device provided with a stacker table supported so as to be movable up and down, and stacking and storing sheets on the stacker table while lowering the stacker table with an increase in the stacking amount of paper discharged onto the stacker table Is conventionally known. This type of paper discharge device may be used by being connected to an electrophotographic device such as a laser printer. In recent electrophotographic apparatuses, a double-sided printing mode that records and forms toner images on both front and back sides of the paper, a paper discharge with the toner image side facing up (face-up paper discharge mode), and vice versa. The operator can freely select a paper discharge mode or the like for discharging paper with the image side facing down (face-down paper discharge mode). In addition, consideration has been given to the paper that can be used in the electrophotographic apparatus so as to be compatible with various paper sizes, paper thicknesses (paper continuous amount), and paper quality.
[0003]
[Problems to be solved by the invention]
As a system for fixing a toner image formed on a sheet using a known electrophotographic process to the sheet, an electrophotographic apparatus generally employs a heat fixing roller system. The paper discharged through this type of heat fixing roller system is subject to thermal contraction due to the heating action, and the leading edge and the trailing edge of the sheet tend to warp toward the surface having the toner image and are likely to be bent. Thus, for example, when a toner image is thermally fixed on one side of a sheet, and then the sheet is discharged in the face-up discharge mode, it curves upward (in a U shape when the sheet is viewed from the side). When the paper is discharged in the face-down paper discharge mode, it tends to bend downward.
[0004]
In the conventional paper discharge device, the bending direction of the paper due to the paper discharge mode of the electrophotographic apparatus is not considered, and the paper discharge operation is always performed under a constant paper discharge condition. When trying to take in the paper into the paper discharge device, the paper cannot be guided to the transport means in the paper discharge device, and over the guide means provided in front of the transport means, the paper stacking failure I was invited.
[0005]
The object of the present invention is to judge the curving direction of the ejected paper based on the paper ejection mode from the host device, control the interval (height) of the paper path according to the curving direction, and stack the paper satisfactorily. It is an object of the present invention to provide a paper discharge device capable of performing the above.
[0006]
[Means for Solving the Problems]
The above object has a stacker table supported so as to be movable up and down, and stacks and accommodates sheets on the stacker table while lowering the stacker table as the amount of sheets discharged onto the stacker table increases. And a guide unit that is provided above the stacker table and guides the paper discharged onto the stacker table to a predetermined position, and the paper discharged on the stacker table is discharged in a curved downward direction. In this case, the gap between the upper surface of the stacker table or the uppermost position of the stacked sheet stacked on the stacker table and the guide unit is restricted to a narrow interval, and the sheet is discharged on the stacker table. When the paper is discharged in an upward curved state, the top surface of the stacker table or the stacker And the lowermost position of the stacked paper sheets central portion stacked on mosquito table, and a control means for regulating a wide interval distance between said guide means is achieved by providing a.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic front view showing the overall configuration of the paper discharge device of the present invention, FIG. 2 is a schematic side view for explaining a stacker table lifting mechanism in the paper discharge device of the present invention, and FIG. 3 is a paper discharge of the present invention. It is a timing chart in an apparatus.
[0008]
The configuration of the paper discharge device according to the present invention will be described with reference to FIGS.
In the figure, reference numeral 2 is a table support member. As shown in FIG. 2, one end of the belt member 3 is fixed to one end of the table support member 2. The belt member 3 is folded back by a bar member 4a fixed at a predetermined position, and the other end of the belt member 3 is fixed to the shaft 4b. Here, the shaft 4 b is provided so as to be rotationally driven by the motor 5. Further, a stacker table 1 is provided on the table support member 2 so as to be detachable from the table support member 2. When a predetermined amount of paper is loaded on the stacker table 1, the stacker table 1 is moved from the table support member 2 to the stacker table 1. The entire table 1 can be taken out and transported.
With the above configuration, the table support member 2 rises when the shaft 4b is rotated in the direction of winding the belt member 3, and descends when the shaft 4b is rotated in the direction of rewinding the belt member 3.
[0009]
Reference numeral 11 is a stopper. The stopper 11 is fixed to a frame (not shown) or the like so as to be positioned near the side edge of the stacker table 1. Above the stacker table 1, a paper transport paddle 9 that transports the paper 12 discharged to the stacker table 1 toward the stopper 11 is provided. Further, a guide member 10 that guides the leading end of the paper 12 discharged to the stacker table 1 to the paper transport paddle 9 is provided in the vicinity of the paper transport paddle 9. Here, the paper transport paddle 9 is provided so as to be rotationally driven by a motor 13.
[0010]
Further, above the stacker table 1, a first detector 7 constituted by, for example, an actuator type photo interrupter, and a second detector provided at a position lower than the first detector 7 by an interval L. 8 are provided.
In FIG. 1, reference numeral 15 is a paper conveyance roller, and the paper conveyance roller 15 is provided so as to be rotationally driven by a motor 14.
Further, the table support member raising / lowering motor 5, the paper conveyance paddle motor 13, the paper conveyance roller motor 14, the first detector 7 and the second detector 8 are connected to the control device 6.
[0011]
Next, the operation of the paper discharge device of the present invention will be described with reference to FIG. In the following description, in the paper discharge mode in which the distance between the upper surface of the stacker table 1 or the central portion of the stacked sheets 12 stacked on the stacker table 1 and the guide member 10 should be restricted to a narrow interval (hereinafter referred to as “the sheet discharge mode”) , Referred to as “first paper discharge mode”) and a paper discharge mode in which the interval should be restricted to a wide interval (hereinafter referred to as “second paper discharge mode”).
[0012]
(First paper discharge mode) When the host apparatus is an electrophotographic apparatus such as a laser printer, as a paper discharge mode that should be restricted to a narrow interval, for example, the face This corresponds to a mode in which the paper is discharged in a down state, or a mode in which the paper after double-sided printing is discharged as it is without being reversed. That is, in these modes, the sheet tends to be discharged in a downward curved state. Therefore, the uppermost position of the stacker table 1 upper surface or the central portion of the stacked sheets 12 stacked on the stacker table 1 and the guide member The interval with 10 is defined as narrow as possible, and a paper discharge operation without waste can be performed.
[0013]
In the first paper discharge mode, the motor 5 is driven by the instruction from the control device 6 to raise the table support member 2. With this ascending operation, the uppermost position of the upper surface of the stacker table 1 or the central portion of the sheet discharged onto the stacker table 1 first activates the second detector 8 and the output of the second detector 8 is logical. “H (high)”. Further, when the table support member 2 is raised, the uppermost position of the upper surface of the stacker table 1 or the central portion of the sheet discharged onto the stacker table 1 activates the first detector 7 to activate the first detector 7. Is also at a logic “H” level.
[0014]
When the outputs of the first detector 7 and the second detector 8 become logic “H”, the ascending operation of the table support member 2 is stopped, and then the motor 5 is turned on for a time T1 according to an instruction from the controller 6. The table support member 2 is lowered and the table position is controlled.
[0015]
3A, the first detector 7 detects the uppermost position of the upper surface of the stacker table 1 or the center of the sheet discharged onto the stacker table 1 even after the time T1 has elapsed. If it is, the motor 5 is further driven for a time T2 in accordance with an instruction from the control device 6, and the first detector 7 detects the uppermost position of the upper surface of the stacker table 1 or the center of the sheet discharged onto the stacker table 1. Move it down to the position where it stops.
[0016]
Sheet loading starts from the position where the table position control is completed. In response to an instruction from the control device 6, the motor 14 is driven to transport the paper 12 by the paper transport roller 15 when transporting the paper 12 to be stacked. Or between the uppermost position of the central portion of the stacked sheets 12 stacked on the stacker table 1 and the guide member 10. At the same time, the control device 6 manages the number of stacked sheets. Further, the conveyed paper 12 is conveyed until it abuts against the stopper 11 by the contact of the paper conveyance paddle 9.
[0017]
After a predetermined number of sheets (set to three in this embodiment) are conveyed onto the stacker table 1 and before the next sheet reaches the stacker table 1, an instruction from the control device 6 is given. After the motor 5 is driven and the stacker table 1 is raised to a position where the first detector 7 detects the uppermost position of the central portion of the stacked paper 12, the motor 5 is moved for a time T1 according to an instruction from the control device 6. Driven to lower the stacker table 1 by a predetermined amount. If the first detector 7 detects the uppermost position of the central portion of the stacked paper 12 even though the time T1 has elapsed, the motor 5 is further driven for the time T2 according to an instruction from the control device 6. The first detector 7 is lowered to a position where the uppermost position of the central portion of the stacked sheets 12 is not detected.
[0018]
By starting the stacking of sheets from the position where the table position control is performed as described above, it becomes possible to make the interval between the uppermost position of the central portion of the stacked sheets 12 and the guide member 10 substantially constant, The conveyed paper can be smoothly conveyed to the stopper 11. In this embodiment, the number of sheets to be stacked is set to three. However, by adjusting the number of sheets to be stacked, the center of the stacked sheets 12 decreases each time the sheets are stacked. It is possible to change the interval between the uppermost position of the section and the guide member 10, and it is possible to stack the sheets satisfactorily.
[0019]
(Second paper discharge mode) When the host apparatus is an electrophotographic apparatus such as a laser printer, as a paper discharge mode that should be regulated at a wide interval, for example, the face This corresponds to a mode in which the paper is ejected up, or a mode in which the paper after duplex printing is reversed and ejected. That is, in these modes, since the sheet tends to be discharged in a state of being curved upward, the lowest position of the stacker table 1 upper surface or the central portion of the stacked sheets 12 stacked on the stacker table 1 and the guide member It is necessary to form a paper path so that the paper is accurately fed into the paper transport paddle 9 without the paper being over the guide member 10.
[0020]
In addition to the above case, the main paper discharge mode corresponds to a mode in which a large size paper such as A3 size paper is discharged regardless of single-sided printing / double-sided printing.
[0021]
In the second paper discharge mode, the motor 5 is driven by the instruction from the control device 6 to raise the table support member 2. With this ascending operation, the lowermost position of the upper surface of the stacker table 1 or the central portion of the sheet 12 discharged onto the stacker table 1 activates the second detector 8, and the output of the second detector 8 is logically “ H (high) ".
[0022]
In the first paper discharge mode, the table support member 2 is further raised to a position where the first detector 7 is operated. In the second paper discharge mode, the second detector 8 is operated. At that time, the ascending operation is stopped and the first detector 7 is not raised to the position where it is operated. That is, when the output of the second detector 8 is logic “H” and the output of the first detector 7 is logic “L (low)”, the raising operation of the table support member 2 is stopped.
[0023]
Thereafter, the motor 5 is driven for a time T1 in accordance with an instruction from the control device 6, and the table support member 2 is lowered to perform table position control.
[0024]
As shown by a broken line in FIG. 3B, the second detector 8 detects the lowest position of the upper surface of the stacker table 1 or the center of the sheet discharged onto the stacker table 1 even after the time T1 has elapsed. If it is, the motor 5 is further driven by the instruction from the control device 6 for a time T2, and the second detector 8 detects the lowest position of the upper surface of the stacker table 1 or the central portion of the sheet discharged onto the stacker table 1. Move it down to the position where it stops.
[0025]
Sheet loading starts from the position where the table position control is completed. In response to an instruction from the control device 6, the motor 14 is driven to transport the paper 12 by the paper transport roller 15 when transporting the paper 12 to be stacked. Or between the lowermost position of the central portion of the stacked sheets 12 stacked on the stacker table 1 and the guide member 10. At the same time, the control device 6 manages the number of stacked sheets. Further, the conveyed paper 12 is conveyed until it abuts against the stopper 11 by the contact of the paper conveyance paddle 9.
[0026]
After a predetermined number of sheets (set to three in this embodiment) are conveyed onto the stacker table 1 and before the next sheet reaches the stacker table 1, an instruction from the control device 6 is given. After the motor 5 is driven and the stacker table 1 is raised to a position where the second detector 8 detects the lowest position of the central portion of the stacked paper 12, the motor 5 is moved only for a time T1 by an instruction from the control device 6. Driven to lower the stacker table 1 by a predetermined amount. If the second detector 8 detects the lowest position of the central portion of the stacked paper 12 even though the time T1 has elapsed, the motor 5 is further driven for the time T2 according to an instruction from the control device 6. The second detector 8 is lowered to a position where the lowest position of the central portion of the stacked paper 12 is not detected.
[0027]
By starting the stacking of sheets from the position where the table position control is performed as described above, the interval between the position of the central portion of the stacked sheets 12 and the guide member 10 is widened by the interval L compared to the case of the first paper discharge mode. It becomes possible to regulate, and the conveyed paper can be smoothly conveyed to the stopper 11. In this embodiment, the number of sheets to be stacked is set to three. However, by adjusting the number of sheets to be stacked, the center of the stacked sheets 12 decreases each time the sheets are stacked. It is possible to change the interval between the position of the portion and the guide member 10, and it is possible to stack the sheets satisfactorily.
[0028]
Next, another embodiment of the paper discharge device of the present invention will be described with reference to FIG.
In addition, about the member of the same structure as FIG. 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted. A difference from the configuration of FIG. 1 is that a concave portion 1 a is provided on the upper surface portion of the stacker table 1 facing the second detector 8, thereby prohibiting the detection of the upper surface of the stacker table 1 by the second detector 8.
[0029]
In this case, the second detector 8 does not detect the upper surface of the stacker table 1, and when even one sheet is discharged on the upper surface of the stacker table 1, the second detector 8 operates by contacting with the sheet. Used as presence / absence detection means.
[0030]
When the second detector 8 is used as the sheet presence / absence detection means as described above, the control device 6 ′ allows the stacking that is stacked on the upper surface of the stacker table 1 or the stacker table 1 in the case of the first discharge mode. The uppermost position of the central portion of the paper 12 is raised to a position where the first detector 7 is activated. Further, in the case of the second discharge mode described above, and when no sheets are discharged on the stacker table 1, the top surface of the stacker table 1 is moved to the first position similarly to the first discharge mode. Is raised to a position where the detector 7 is operated. Further, in the case of the above-described second discharge mode and when the sheet is discharged onto the stacker table 1, the lowest position of the central portion of the sheet discharged onto the stacker table 1 is set to the second position . The detector 8 is raised to a position where the detector 8 is operated. Even in such a configuration, the same effect as that of the configuration of FIG. 1 can be obtained.
[0031]
In the present invention, the signal for switching between the first discharge mode / second discharge mode is a signal output depending on whether the operator has selected the single-sided printing mode or the double-sided printing mode, or , Based on a signal output depending on whether the operator has selected a mode for reversing and discharging the printed paper, or a mode for discharging without reversing, or a signal based on the paper size selected by the operator, etc. When these signals are input to the control device 6, an appropriate paper discharge mode is selected from the first paper discharge mode and the second paper discharge mode.
[0032]
【The invention's effect】
As described above, according to the present invention, the curving direction of the ejected paper is determined based on the paper ejection mode from the host apparatus, the interval of the paper path is controlled by the curving direction, and the paper is loaded satisfactorily. It is possible to provide a paper discharge device that can perform the above operation.
[Brief description of the drawings]
FIG. 1 is a schematic front view showing an overall configuration of a paper discharge device according to the present invention.
FIG. 2 is a schematic side view for explaining a stacker table lifting mechanism in the paper discharge device of the present invention.
FIG. 3 is a timing chart in the paper discharge device of the present invention.
FIG. 4 is a schematic front view showing another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Stacker table, 2 ... Table support member, 3 ... Belt member, 4b ... Shaft, 5, 13, 14 ... Motor, 6 ... Control apparatus, 7 ... 1st detector, 8 ... 2nd detector, 9 ... paper transport paddle, 10 ... guide member, 11 ... stopper, 12 ... paper, 15 ... paper transport roller.

Claims (5)

A paper discharge device having a stacker table supported so as to be movable up and down, and stacking and storing sheets on the stacker table while lowering the stacker table with an increase in the stacking amount of sheets discharged onto the stacker table In
A guide means provided above the stacker table, for guiding the paper discharged onto the stacker table to a predetermined position;
When the paper discharged on the stacker table is discharged in a downward curved state, the uppermost position of the upper surface of the stacker table or the central portion of the stacked paper stacked on the stacker table, and the guide means When the paper discharged on the stacker table is discharged in an upwardly curved state, the upper surface of the stacker table or the central portion of the stacked paper stacked on the stacker table is controlled . A paper discharge device comprising: a lowermost position; and a control means for restricting a distance between the guide means to a wide distance. A paper discharge device having a stacker table supported so as to be movable up and down, and stacking and storing sheets on the stacker table while lowering the stacker table with an increase in the stacking amount of sheets discharged onto the stacker table In
A guide means provided above the stacker table, for guiding the paper discharged onto the stacker table to a predetermined position;
First detection means provided above the stacker table so as to be able to detect the position of the upper surface of the stacker table or the central portion of the stacked sheets stacked on the stacker table;
Second detection means provided at a position lower by a predetermined interval than the first detection means;
Control means for controlling the table position of the stacker table by raising the stacker table once every time a predetermined number of sheets are stacked on the stacker table and then lowering the stacker table by a predetermined amount;
When the sheets discharged onto the stacker table are discharged in a downward curved state, the uppermost position of the upper surface of the stacker table or the central portion of the stacked sheets stacked on the stacker table is the first position . Raise the detection means to the position to operate,
When the paper discharged on the stacker table is discharged in an upward curved state, the lowest position of the stacker table upper surface or the central portion of the stacked paper stacked on the stacker table is the second position . A paper discharge device which raises the detection means to a position where it operates. 3. The exhaust according to claim 2, wherein a concave portion for avoiding contact between the second detection means and the upper surface of the stacker table is provided on the upper surface portion of the stacker table facing the second detection means. Paper device. In the case where the paper discharged on the stacker table is discharged in a state of being curved upward, and when no paper is discharged on the stacker table, the upper surface of the stacker table is 3. The paper discharge apparatus according to claim 2, wherein the first detection means is raised to a position where the first detection means is operated. An electrophotographic apparatus comprising the paper discharge device according to claim 1.

Images