JP3069395B2 - Elevating tray 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 lifting tray device for vertically driving a tray for stacking and storing sheets on which images are to be formed.

[0002]

2. Description of the Related Art As a paper feeding port of a copying machine, there are two to four stages.
Although the capacity of the paper cassette is generally 250 to 500 sheets, some users often make a copy of a specific paper size (for example, A4). A large number of trays are made as options. A large number of trays (hereinafter referred to as LCT)
Sheets, 2000 sheets, 3000 sheets, and the like. Further, the high-speed machine is provided with a paper feed tray instead of a paper feed cassette as standard equipment, and a capacity of about 1000 to 2500 sheets can be stacked.

[0003]

However, the current LC
As a method of replenishing paper to T, once the lowering switch is turned on, the tray is lowered and stopped until it is detected by the lower limit detecting unit. Therefore, LCT with a large number of loaded
Therefore, the lower the number of stacked sheets, the longer it takes to descend. For example, when dozens of special papers (color paper, OHP, second base paper) are added to the LCT for copying, the LCT only needs to be lowered and stopped by the added number of sheets, but the lower limit detection position is reached. Since the lowering occurs, there is a problem that the user has to wait for the total time of the descending time and the time when the tray is moved up to the sheet feeding position after the paper is added.

An object of the present invention is to provide a lifting tray device which can reduce the waiting time when replenishing sheets (sheets) and improve the workability.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a lifting tray device comprising a tray for loading sheets, switch means for lowering the tray, and driving means for raising / lowering the tray. In the driving means
As a result, the falling signal by the switch means is longer than a predetermined time.
If it is shorter, lower the tray to the lower
When the descent signal from the switch means is longer than the specified time
Lowers the tray, and the lowering signal is
First hand to stop descent when it has run out
Achieved by steps . A tray for further stacking sheets, and switch means for lowering the tray, before
In lifting tray device and drive means for raising / lowering the serial tray, from the drive means, said Sui
When the descending signal by the switch is shorter than a predetermined time,
Lowering the tray to the lower limit,
Signal is generated again by the switch means during the falling of
When the descent signal disappears, the descent
This is achieved by a second means adapted to stop .

[0006]

In the first means, the lower means by the switch means is provided.
If the down signal is shorter than the specified time, lower the tray to the lower limit.
The switch is lowered, and the lowering signal from the switch
If it is long, lower the tray and
Stop descent when the descent signal is gone
Stop the tray when the paper supply conditions are met
Workability is improved, and
Wasted time is gone. In the second means, a switch
If the descending signal by the means is shorter than the predetermined time,
A while lowering the tray to the lower limit.
Again when a lowering signal is generated by the switch means.
Stops descent when the descent signal disappears
Therefore, during the lowering of the tray to the lower limit,
In addition , the tray can be stopped when the sheet replenishment condition is met, workability is improved, and wasted time due to tray vertical movement is eliminated.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a schematic diagram of a copier using one embodiment of the present invention, in which 1 is an image forming unit formed by a known electrophotographic process, 2 is an automatic document feeder (ADF), and 3 is a document scanning device. The optical systems 4 and 5 are paper feed cassettes provided on the right side of the image forming unit 1, 6 and 7 are paper feed cassettes provided on the cassette housing 8, and 9 is provided on the left side of the image forming unit 1. The LCT is mounted in place of the paper cassette 5.

FIG. 3 is a block diagram showing the details of the paper feed cassettes 4 and 5 shown in FIG. 2. In the upper and lower two-stage paper feed cassette mounting parts 4a and 5a, a lower paper feed cassette mounting part 5a is provided. LCT is attached to each stage, 10 of each stage is a call roller, 1
1 is a paper feed roller, 12 is a reverse rotation roller, 13 is a relay roller, 14 is a registration detection sensor, 15 is a registration roller, 16 is a PTL, 17 is a paper detection sensor, and 18 is a photosensitive drum of the image forming unit 1. , 19 are tray raising arms.

FIG. 4 is a perspective view showing a tray upper limit detecting section.
And a paper feed clutch 21 for controlling the rotation of these rollers 10, 11; 22, a working rod provided on the frame 20; An upper / lower tray detection unit 24 is a call solenoid.

FIG. 5 is a perspective view showing a schematic configuration of the LCT, 26 is a tray, 27 is a side guide for guiding the tray up and down, 28 is a tray lower limit detecting unit provided below the tray 26, 29 is a paper size adjustment dial, 3
0 is a lowering switch for lowering the tray 26, 31 is LC
This is a door open display unit that indicates that a door (described later) covering T is open.

FIG. 6 is a perspective view showing an LCT drive unit.
32 is a pair of tray support shafts for supporting the tray 26,
Reference numeral 33 denotes a tray motor; 34, two tray drive wires that move by receiving a driving force from a driving force transmitting unit described later to move the tray support shaft 32 up and down; and 35, a plurality of pulleys that support the tray driving wire 34 It is.

FIG. 7 is a perspective view showing a sheet remaining amount detecting portion. Reference numeral 37 denotes a worm gear provided on an output shaft 33a of the tray motor 33.
And a drive gear 38 having a winding portion 38a around which the driving force is transmitted. Reference numeral 39 denotes a shield plate that moves up and down via a remaining amount detection wire 41 in response to rotation of the rotating shaft 40 of the drive gear 38, and 42 denotes a tray paper remaining amount that includes five photo sensors and detects the position of the shield plate 39. It is a detection unit.

FIG. 8 is a perspective view showing a door switch portion, wherein 43 is an upper actuator which is rotated by an upper door 44, 45 is a lower actuator which is rotated by a lower door 46, and 47 is an upper actuator. This is a door switch which receives the movement of the lower actuators 43 and 45 via the switch actuator 48 and turns on / off.

FIG. 9 is a perspective view showing a size detecting section. Reference numeral 50 denotes an eccentric part of which is inserted into the drive lever pin 51 of the side guide 27 and the other part is formed on the paper size adjusting dial 29. A drive lever inserted into the groove 52, 53 is a size detection plate provided for each size position of the paper size adjustment dial 29, and 54 is composed of five photo sensors, and the size is detected by reading the size detection plate 53. A size detection unit, 55 is a fixed position actuator,
Reference numeral 56 denotes a fixed position detection switch that is turned on / off by the fixed position actuator 55.

Next, the operation of the above embodiment will be described.
FIG. 10 is a flowchart showing an outline of the entire copying operation. When power is turned on, CPU (Central Processing Unit)
Is based on the program written in the ROM,
Initialize the PU (set input / output ports, set initial values for each parameter, set various timers, set interrupt mode, etc.), clear the contents of the RAM, and execute the copy operation of the contents of the nonvolatile memory. Relevant ones, for example, a set value of a lamp voltage, a set value of a bias voltage, and the like are loaded into the RAM. Further, mechanical initialization such as a scanner of the optical system 3 is performed, and when the fixing temperature reaches a predetermined density (reload), a standby state is set. Then, the copying operation is started by the copy start signal, and when a predetermined number of copies are completed, the copying machine enters the standby state again.

When the main switch is turned on, the tray motor 33 rotates and moves the tray drive wire 34 to lift the sheet on the tray 26 via the tray support shaft 32 to a certain height. When the tray 26 rises and the paper lifts the call roller 10, the tray upper limit detection unit 23
Is turned on by the operating rod 22 which rises together with the calling roller 10, and the trigger of the tray motor 33 is turned off. Then, when the copy start switch is turned on, the paper feed clutch 21 is turned on, and the paper is sent out to the paper feed roller 11 by the calling roller 10. Next, the call solenoid 24 is turned on, and the call roller 10 separates from the sheet to release the pressurization. The paper is conveyed to the registration rollers 15 with the double feed prevented by the known operation by the paper feed rollers 11 and the reverse rotation rollers 12.

When the tray 26 rises, the rotating shaft 40 rotates to move the remaining amount detection wire 41, and the movement of the remaining amount detection wire 41 causes the shielding plate 39 to operate the photo sensor of the tray paper remaining amount detection unit 42. Detected by blocking light. When the upper door 44 and the lower door 46 are opened, the tray motor 33 is stopped, and the detection is performed by the door switch 47. That is, when the upper actuator 43 is pressed by the upper door 44 and the lower actuator 45 is pressed by the lower door 46, the switch actuator 48 is turned on by the door switch 4.
Press 7 The display on the door open display section 31 is made by this detection signal.

The paper size is adjusted by rotating the paper size adjustment dial 29. When the paper size adjustment dial 29 is turned, the drive lever 50 moves along the eccentric groove 52, and the side guide 27 moves to each size position.
Then, the size detection plate 53 provided for each size position of the size adjustment dial 29 is read by five photo sensors of the size detection unit 54 to detect the size. The fixed position detection switch 56 is designed so that when the paper size adjustment dial 29 comes to each size position, the fixed position actuator 55 falls into the groove and turns off. Only when the fixed position detection switch 56 is off, , Size detection (paper size adjustment dial 2
9 is erroneously detected when performing size detection at an intermediate position).

FIG. 1 is a flow chart of a tray motor control operation. FIG. 1 (a) relates to motor control by a descending switch, and FIG. 1 (b) relates to motor control by door opening / closing. The FDSW is a flag for controlling the lowering and stopping of the tray motor 33 by the lowering switch 30.

In FIG. 1A, when a sheet is present on the tray 26 and the tray upper limit detecting unit 23 is turned on,
When the descending switch 30 is turned on, the FDSW is raised only while the descending switch 30 is on, and the tray motor 33 is turned on.
Is rotated in a direction to lower the tray 26. When the descending switch 30 is turned off, the rotation of the tray motor 33 is stopped, and the movement of the tray 26 is stopped.

In FIG. 1B, when the doors 44 and 46 are open, the tray motor 33 stops, and when the doors 44 and 46 are closed after replenishing the sheets, the FDSW is lowered and the tray motor 33 is moved to the tray 26. It is rotated in the ascending direction and stopped at a predetermined paper feed position. When the paper runs out from the tray 26, the tray 26 is automatically lowered to a predetermined position by detecting the absence of the paper. In yet closing of the door 44, 46 of the tray 26 in descending, is lowered to a predetermined position, may be raised tray 2 6 door at that time, be raised tray 26 at the door opening and closing during descent good. In this way, the position of the tray 26 can be arbitrarily stopped by the operator when replenishing the paper, so that the operability is good and the wasteful time of raising / lowering the tray is eliminated.

FIGS. 11A to 11C are flow charts for explaining another control operation of the tray motor.
First, the symbols in the figure will be described. Tm: descending switch 3
Set value of ON time discrimination of 0 (for example, 5), FDWN: flag. This is for lowering the tray motor 33 even when the lowering switch 30 is off, and is set when the on-time of the lowering switch 30 is short from Tm.
STP: flag. A counter for stopping the tray motor 33 when the descending switch 30 is turned off and set when the on-time of the descending switch 30 is long from Tm, CNTDW: counter. Which count A tool for up (+1) to 100msec every on-time of the lowering switch 30, FCVE: flag. This is set when the doors 44 and 46 of the LCT open and close.

In FIG. 3, the descending switch 30 is depressed, and its ON time is within the time Tm (for example, 500 msec).
For c), the tray 26 is stopped lowered to the lower limit detection unit 28 (mode 1). If the on-time is equal to or longer than the Tm time, the descent continues while the switch is turned on from the Tm time, and stops when the switch is turned off (mode 2). Further, during the lowering of the tray in mode 1, the lowering switch 30 is again turned to the T position.
If the switch is turned on for m hours or more, the mode is set to mode 2 and stopped when the descending switch 30 is turned off. After the above operation, paper is supplied by opening the doors 44 and 46, and then the door 4 is opened.
The tray 27 is raised by closing the trays 4 and 46, and stops at a predetermined sheet feeding position (a position where the upper limit detection unit 23 is turned on).

[0024]

Effects of the Invention] According to the invention of 請 Motomeko 1, switch means
When the lowering signal is shorter than the specified time,
Lower to the lower limit, and the lowering signal by the switch means is specified.
If it is longer than the time, lower the tray and
Stop descent when the descent signal disappears
The switch means for efficient operation of the switch means.
When lowering the tray to the lower limit, short the switch
Operation can be performed in
When the switch is released, the tray stops.
To improve workability and raise and lower the tray.
Lifting tray device that can reduce wasted time
You. According to the invention of claim 2, the lowering by the switch means
If the signal is shorter than the specified time, lower the tray to the lower limit.
Switch while the tray is descending.
When a descending signal is generated by the means,
As we stopped the descent when there was no more,
Even while the tray is being lowered to the lower limit , the tray can be stopped when the paper supply conditions are met,
It is possible to provide a lifting tray device capable of improving workability and reducing wasteful time due to the vertical movement of the tray.

[Brief description of the drawings]

FIG. 1 is a flowchart of a control operation of a tray motor of a lifting tray device of the present invention.

FIG. 2 is a schematic configuration diagram of a copying machine.

FIG. 3 is a configuration diagram showing details of a paper feeding cassette unit of FIG. 2;

FIG. 4 is a perspective view showing a tray upper limit detection unit.

FIG. 5 is a perspective view showing a schematic configuration of an LCT.

FIG. 6 is a perspective view showing an LCT driving unit.

FIG. 7 is a perspective view illustrating a remaining paper amount detection unit.

FIG. 8 is a perspective view showing a door switch unit.

FIG. 9 is a perspective view showing a size detection unit.

FIG. 10 is a schematic flowchart of the entire copying operation.

FIG. 11 is a flowchart of another control operation of the tray motor.

[Explanation of symbols]

 26 tray 30 descending switch (switch means) 33 tray motor (drive means)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-38336 (JP, A) JP-A-58-125548 (JP, A) JP-A-63-74827 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B65H 1/00-3/68

Claims (2)

(57) [Claims] A tray for stacking 1. A sheet, and switch means for lowering the tray, the lifting tray device and drive means for raising / lowering the tray, from the drive means, said switch The descent signal by means
If the time is shorter than the predetermined time, lower the tray to the lower limit.
And a descent signal from the switch means is output from a predetermined time.
If it is long, lower the tray and
Stop descent when the descent signal disappears.
A lifting tray device. A tray for stacking 2. A sheet, and switch means for lowering the tray, the lifting tray device and drive means for raising / lowering the tray, from the drive means, said switch The descent signal by means
If the time is shorter than the predetermined time, lower the tray to the lower limit.
While the tray is descending.
When a descending signal is generated by the
An elevating tray device , wherein the descent is stopped when the number has disappeared .