JPS6341355A - Sheet loading device - Google Patents

Abstract

PURPOSE:To maintain the superior arrangement performance independently of the loading quantity by reducing the driving time of a lowering means for lowering a loading means whose position is detected by a detecting means. CONSTITUTION:An output paper sheet is transported in a transport passage formed between transport guides 10 and 11 by the transport rollers 7, 6 and 8, 9 and reaches the output roller groups 12-15 and is loaded onto a tray 19 or the loaded paper sheets on the tray 19. when the paper sheets are loaded continuously, the loaded paper sheet surface rises, and a paper discharging roller 14 is lifed np gradually, and when the roller 14 is lifted up to a prescribed position, a controller detects this state by the input supplied from a paper surface sensor 18, and a motor 23 is driven to lower the tray 19. When the motor driving time in the case when the tray 19 is at the uppermost position is set TH, the time in the case when the tray is at an intermediate position is TM, and the time in the case when the tray is at the lowest position is TL, the superior loading arrangement in the case ranging form the large quantity loading to the small quantity loading can be secured by setting TH>TM>TL.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a device for stacking sheets (hereinafter referred to as paper) discharged from a sheet processing device such as a printer or a copying machine.

[Prior art]

2. Description of the Related Art Conventionally, a device having a stacking tray that can be raised and lowered is known as a device for stacking paper discharged from a printer, a copying machine, or the like.

FIG. 7 schematically shows a conventional configuration of a stacking tray of a paper stacking device having a stacking tray that can be raised and lowered. 2 is a paper discharge roller, 2 is a paper discharge port, 3 is a stacking tray, and 4 is a stacked paper stacked on the stacking tray 3.

In Fig. 7, the hard copy output paper is sequentially delivered to the paper ejection roller 1
When the output paper is conveyed by the paper output port 2 and outputted from the paper discharge port 2, the output paper is sequentially stacked on the stacking tray 5, and this becomes the a1 paper 4. When the number of stacked papers 4 increases and the paper surface approaches the paper discharge port 2 by a predetermined amount, a tray lift motor (not shown) is driven for a certain period of time to lower the stacked tray. Further, the timing of this tray descent is given by a stacked paper surface sensor (not shown) that detects when the stacked paper surface has risen to a certain position.

If the output is continued further, the tray lifting motor is driven for a certain period of time so that the tray is lowered every time the paper surface rises to a specified position. That is, during continuous loading, the loading tray 5 is intermittently lowered. FIG. 8 shows a conventional control flowchart for lowering the stacking tray during the loading process.

By the way, MLil on the loading tray! To ensure the alignment of the sheets, the angle of incidence when the paper discharged from the paper discharge port 2 contacts the stacking tray 5 or the already stacked stacked papers 4 is always determined depending on the shape of the stacking tray 5, etc. It is desirable that it be within a certain range. In other words, it is desired that the distance between the paper discharge port 2 and the paper surface of the stacked paper 4 is always within a certain range.

In general, many paper stacking devices having elevating trays carry out large-volume stacking, and the weight of the stacked papers stacked on the stacking tray is thought to vary over a wide range. In other words, the load applied to the loading tray lifting motor also varies over a wide range. Therefore, in the control that detects only the paper surface and drives the motor for a certain period of time as described above, the motor speed or, in the case of a constant speed control motor, the rise time changes depending on the load, so the difference between the paper ejection port 2 and the paper surface of the stacked paper 4 changes. There was a problem in that the distance was no longer within a range that guaranteed alignment of the stacked sheets.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet stacking device that eliminates the problems of the conventional example described above and can always guarantee good alignment of stacked sheets regardless of the stacking amount.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 6 show embodiments of the present invention. FIG. 1 shows the main cross section of the stacking section of the paper stacking device according to the present invention.
, 7, 8.9 are conveyance rollers that convey the paper in the stacking device;
10.11 is a conveyance guide that defines a paper conveyance path; 12.
Reference numerals 13, 14, and 15 refer to a group of paper ejection rollers that eject the conveyed paper to a later-described stacking tray; 16, a paper ejection belt that is wrapped around the paper ejection rollers 14 and 15; This sensor (photointerrupter) detects the presence or absence of paper on the conveyance path leading to No. 15, and is hereinafter referred to as a paper discharge sensor.

Reference numeral 18 denotes a sensor (photointerrupter) that detects the paper surface of the stacked paper, which will be described later, based on the position of the paper discharge roller 14, and is hereinafter referred to as a paper surface sensor. 19 is a tray on which the paper discharged from the paper discharge roller is stacked; 20 is a stack of paper stacked on the tray 19;
A sensor 21 detects the presence or absence of paper in the tray 19, and is hereinafter referred to as a tray paper presence/absence sensor. Reference numeral 22 denotes a tray drive unit that controls lifting and lowering of the tray 19, 23 a DC motor that provides driving force for lifting and lowering the tray, and 24, 25.

26 is a group of gears that converts the rotational force of the DC motor 23 into a force for lifting and lowering the tray.

FIG. 2 shows the tray drive unit 22 in FIG.
It is a transparent view seen from above. 27゜29 is a micro switch for detecting the lowering position of the tray, 28.30
is a lever for turning on microswitches 27, 29 and 29 when the shapes of ribs 31 and 32 are changed, which will be described later. Figure 3 shows a microswitch 27.29 (7) ONloFF (7) state trifle 31 using ribs 31 and 32.
It is a figure showing the shape of °32. As shown in Figure 3, the microphone 0SW27.29(7) ON10FF state changes to 27.29 (7) as the tray descends. ON/29, 0N-27
, OFF/29, ON →27.

OFF/29. It changes to OFF.

FIG. 4 is an electrical block diagram of the configuration shown in FIGS. 1 to 3. 33 is a loading device according to the present invention, 34 is a hard copy output device such as a printer using 33, 3
5 is a control device for the output device 34, 36 is a control device for the loading device according to the present invention, 37 is a conveyance motor that supplies the paper conveyance force of the JJ loading device, 38 is a microcomputer in the loading device control device,
39 is a RAM that stores information from the microcomputer, and 40 is an RO that stores program information for operating the microcomputer.
M, 41 is an input/output circuit that performs input/output according to instructions from a microcomputer.

FIG. 5 is an example of a system using the paper stacking device according to the present invention. 42 is a paper stacking device according to the present invention, and 43 is a laser beam printer.

Next, paper stacking in the above configuration is performed as follows. First, the output paper output to the wood stacking device is transferred to the conveyance guide 11.
The exit roller groups 12, 13, 14, 15 . reached,
Further, the sheets are discharged and stacked onto the tray 19 or onto the stacked sheets already stacked on the tray 19. As the sheets are further stacked continuously, the surface of the stacked sheets rises, and accordingly, the paper discharge roller 14 is gradually lifted up. When the paper ejection roller 14 is lifted up to a predetermined position, the paper surface sensor 1 detects this.
The control device 36 detects the input from the tray 19
In order to unload the tray, the L motor 23 is driven.

(When the carrier 24 is rotated CCW, the tray is lowered.) However, this motor drive time is not constant but is selectively determined by the 0N10FF states of the microswitches 27 and 29. As can be seen from the explanation of FIG. 3 above, the tray 19 is
In the unimplemented example, the position can be known in three stages.

Here, for example, the motor driving time when the tray 19 is at the top (that is, the loading capacity is small) is TH (S).

When tray 19 is in the middle (medium loading capacity), TM (S),
TL (S) when tray 19 is at the bottom (large loading capacity)
shall be. As the loading amount increases, the motor load for lowering the tray becomes smaller, the rotational speed becomes higher, and the amount of tray lowering per unit time increases. Considering the rotation speed vs. torque characteristics of the motor used,
By setting M>TL, the positional relationship between the paper discharge port and the stacked paper surface can be kept within a range that can guarantee good stacking alignment from the time of bulk loading to the time of submerged loading.

FIG. 6 shows a flowchart of the above descent control according to the present invention.

In the above-described embodiment, a microswitch is used as the tray position detection means, but the present invention is not limited to the tray position detection means.

For example, the tray position may be detected using a slide volume that moves in conjunction with the raising and lowering of the tray.

Further, the above embodiment has been described as loading a single paper size, but when supporting multiple types of paper sizes, it is sufficient to set TH9"r,..., TL depending on the paper size. In this case, for example, TH when loading A3 paper (A3)
, A4 paper J? Letting T+-+ at ta be TH(A4), 4fTH(A3)<TH(A4).

[Effect] As explained above, by changing the driving time of the lowering means that lowers the sheet loading means according to the fit load of sheets, a sheet loading device with good alignment that is not affected by the fit load of sheets can be realized. can.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the loading section according to the present invention;
Fig. 2 is a perspective view of the tray drive unit in Fig. 1 seen from above the tray, Fig. 3 is an explanatory diagram of the operation of the tray head detection microswitch in Fig. 2, and Fig. 4 is an electrical block showing the embodiment. 5 is a diagram showing an example of the system configuration of the embodiment,
FIG. 6 is a flow chart showing the tray lowering control of the embodiment, FIG. 7 is a schematic diagram showing the conventional example, and FIG. 8 is a flow chart showing the tray lowering control of the conventional example. 18...Paper surface sensor, 19...Tray, 21...
Paper presence/absence sensor, 23...DC motor, 27.29...
·Microswitch.

Claims (3)

[Claims] (1) A loading means for stacking sheets conveyed from a sheet processing section, a lowering means for lowering the loading means, and a control means for lowering the loading means by intermittently driving the lowering means during sheet loading. . A sheet loading device, wherein the control means changes the driving time of the lowering means according to the amount of sheets loaded. (2) In claim 1, the control means includes a detection means for detecting the position of the loading means, and based on the position information of the loading means detected by the detection means, the control means detects the position of the lowering means. A sheet loading device characterized by changing driving time. (3) The sheet loading device according to claim 2, wherein the control means reduces the drive time of the lowering means as the position of the loading means lowers.