JP3295971B2 - Paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, such as a copying machine or a printer, in which a sheet cut by suction of air is adsorbed on a conveying means such as a conveying belt and fed from a tray. More specifically, the present invention relates to a paper feeding device capable of feeding in an appropriate suction state regardless of the thickness and type of paper.

[0002]

2. Description of the Related Art Cut paper (hereinafter simply referred to as "paper") stacked on a supply tray is sucked by air (air), adsorbed on a conveyor belt or the like, and fed to a recording unit or the like. Paper devices have been used in the past. Such an air suction type sheet feeding apparatus has an advantage that a double feed is less than that of a feed roller method in which a feed roller is pressed onto a sheet to feed the sheet, and is particularly frequently used in a large-sized apparatus.

FIG. 11 shows a main part of such an air suction type sheet feeding device. A plurality of sheets 12 are stacked on a tray 11 which is vertically movable. The tray 11 is provided with one end of a wire 14 wound around a rotation shaft of an elevator motor 13, and its position is moved up and down in the direction of arrow 15 by forward or reverse rotation of the elevator motor 13. Tray 1
1 is stopped by a sensor 16 which detects the uppermost sheet 12T. That is, when the sensor 16 stops detecting the sheet 12, the elevator motor 13 starts winding the wire 14,
When the paper 12 is detected, the operation is stopped.

[0004] A suction-type transport mechanism 18 is disposed slightly above the sensor 16. Suction-type conveying mechanism 18, a conveyance belt 19 that has been drilled a number of holes for air suction, and has a structure for conveying by the drive roller 21 and the driven roller 22. The suction port 23 is provided inside the suction-type transport mechanism 18.
Are arranged, and the air 24 is sucked by a vacuum motor (not shown). With this suction force, the uppermost sheet 12T is attracted to the transport belt 19 and is transported in the direction of arrow 26. There is also an air jet outlet (not shown) that is provided in addition to jet air from below in order to lift the paper 12 and assist suction thereof.

In such an air suction type sheet feeding apparatus, if sheets of different sizes and thicknesses are sucked and transported under exactly the same conditions, the suction force on some of the sheets is too strong. In some cases, it was damaged, and on the contrary, it was too weak to feed. Therefore, conventionally, an operator appropriately adjusts an appropriate amount of air suction or ejection for each sheet by operating an air adjustment valve.
However, it takes time for the operator to operate the adjusting valve one by one, and the adjustment may not be performed properly. In this case, the above-described trouble at the time of feeding occurs.

Therefore, in the technique described in Japanese Patent Application Laid-Open No. 56-99144, a plurality of suction pressure setting devices are prepared so that one of them can be selected.
The effort of operating the regulating valve is saved.

[0007]

However, if a plurality of suction pressure setting devices are arranged as described above, electromagnetic valves and switches corresponding to the plurality of adjustment valves are newly required in addition to the plurality of adjustment valves. In order to cope with various types of paper, it is necessary to arrange a number of these electromagnetic valves and switches. Therefore, there has been a problem that the paper feeding device itself becomes large and the cost increases. In addition, there is also a problem of noise due to an increase in the amount of air suction and air ejection.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet feeder which can handle sheets of various thicknesses and sizes with a simple mechanism.

[0009]

According to the first aspect of the present invention, there is provided a supply tray for accommodating sheets of paper, and the supply tray accommodates the sheets.
Enter the size and type of paper loaded
Input means such as a keyboard or host computer
Lifting means for raising and lowering the supply tray;
The uppermost layer of paper that is
After sucking and adsorbing to the specified site,
Paper feeding means to send out and the size of the input paper
And the type stored in the supply tray based on the type of paper
Set an appropriate distance between the top layer of paper and
Calculating interval calculating means and calculating the calculated interval
Elevating means controlling means for controlling the elevating means, and
Be prepared.

That is, according to the first aspect of the present invention, the supply
The size and type of paper stored in the keyboard
And the like, and based on this, the top layer of the paper
The distance between the air and the predetermined area where air is absorbed
To control the raising and lowering of the supply tray.
You.

[0011]

【Example】 First, a reference example which is a reference for explanation of the present invention will be shown.
Then, an embodiment of the present invention will be described.

First Reference Example

FIG . 1 shows the side of the sheet feeding device in the first reference example.
It shows a schematic configuration when viewed from a plane. Figure 1
The same parts as those in FIG.
Description is omitted as appropriate. In this paper feeder, the transport belt 19
The contact sensor 33 projects slightly from the lower surface of the
Is arranged. This corresponds to the sensor 16 shown in FIG.
No sensors are located.

FIG . 2 shows the arrangement of the contact sensors from the front.
It was done. Of the air duct 34 of the conveyor belt 19
A contact sensor 33 composed of a microswitch or the like is provided on the lower surface.
Is placed. The contact sensor 33 detects that the paper 12
This is detected when it is adsorbed on the reference numeral 19.

FIG . 3 shows a main part of a circuit configuration of the paper feeder.
It is a representation. This paper feeder is
A CPU (central processing unit) 41 is mounted. CPU4
1 is a ROM 43, a RAM 44,
Memory (NVM) 45, vacuum motor drive circuit
46, elevator motor drive circuit 47 and input circuit 4
8 is connected.

Here, the ROM 43 stores the sheet
Reads that store programs for various controls such as control
-Only memory. RAM 44 is a working memory
And is composed of random access memory
I have. Non-volatile memory 45 is a table necessary for paper feed control
A memory storing the like, bar by a battery (not shown)
Has been backed up. Vacuum motor drive circuit 46
Controls the drive of the vacuum motor 51 and controls the suction port 2
The air is sucked from 3. elevator
The motor drive circuit 47 drives the elevator motor 13
Control is performed to move the supply tray 11 up and down. Input circuit 48
Includes a vertical position sensor 31, a contact sensor 33, and an operation panel.
The channel 53 and the clock circuit 54 are connected. Operation panel
An image forming apparatus using this paper feeding device
A key switch for performing the above operation is arranged. Time
The measuring circuit 54 is a circuit for measuring time, and
In the example, the uppermost sheet 12T is attracted to the transport belt 19.
It is mainly used to measure the time required to complete.

FIG . 4 shows a supply tray of the sheet feeding device of this reference example.
Initial control when replacing or refilling the paper
It is a representation. Replacement or replenishment of paper 12 is performed
(Step S101; Y), the CPU 41
The contact sensor 33 is controlled by controlling the
The elevator motor 13
The supply tray 11 is raised (step S102,
S103). In this way, the uppermost sheet 12T comes into contact
When the sensor 33 is turned on by contacting the sensor 33 (step S10
2; Y), the CPU 41 stores the data in the nonvolatile memory 45 in advance
Under the current position corresponding to the reference position Y _A being
The data indicating the descending amount is read and the elevator motor
By controlling the path 47, the supply tray 11 is
(Step S104). in this way
And the distance between the top sheet 12T and the contact sensor 33
Is set at a position Y _A, the sheet feeding is performed in a standard manner
State.

[0018] It is to be noted that the reference position Y _A serviceman customers
Listen to the usage of
May be set in advance, or the previous supply
The optimal value for ray 11 can be used as is,
The average value of the appropriate value and the standard value may be adopted.
No.

FIG . 5 shows a state after the initial control is performed.
This shows the state of raising and lowering control of the supply tray . this
Start not shown in the image forming apparatus using the paper feeder
When the recording of an image is started by pressing a button, etc.
(Step S201; Y), the CPU 41 carries the paper 12
When the driving of the vacuum motor 51 is started for feeding
The device is monitored (step S202). And vacuum
When the motor 51 is turned on, the clock circuit 54
The measurement is started (Step S203). Measurement is contact
The process is performed until the sensor 33 detects the uppermost sheet 12T.
(Step S204; Y, S205). CPU 41
As a result, after the vacuum motor 51 is turned on,
The required time t until the sensor 33 is turned on is calculated, and the position is calculated.
Determining the optimum position Y _B with use table (step S
206).

FIG . 6 shows positions stored in the nonvolatile memory.
It shows an example of the contents of a calculation table.
Now, assuming that the required time t is t _B ,
The optimal position Y _B crossing the characteristic curve 61 is obtained as
Can be The characteristic curve 61 is a curve obtained experimentally.
You. This using calculation formula for the optimum position Y _B is the device
May be calculated.

Once the optimum position Y _B has been found, the current position
Y _A + C (Numerical value C is a standard addition per sheet of paper 12)
Comparing the calculated amount) and the optimum position Y _B, towards the optimum position Y _B
Is larger, i.e., lower the supply tray 11
If it is better to let
A is lowered (step S207). Conversely,
The smaller the better of a suitable position Y _B, that is more supply tray
If it is better to raise (approach) b11, the amount
Only the supply tray 11 is raised. The number
Since the value C is the thickness of the standard paper 12, an error occurs.
However, this correction is performed every time recording starts.
Therefore, practical inconvenience does not occur.

In the first embodiment described above, the supply
Raise the tray 11 once and touch the top layer paper 12T
After contacting the sensor 33, adjust the interval for suction.
Was. Instead, the arrangement of the sensor 16 shown in FIG.
Or one-dimensional image sensor in the vertical direction
A plurality of sensors are arranged, use with these sensors output
The position of the uppermost layer of the paper 12 is directly determined to perform position control.
You may do so.

Second Reference Example

In the first reference example, the time required for sucking the paper
Measure and adjust the distance from the suction mechanism to the
Tried to determine the size and type of paper, and
Set the distance to the suction mechanism directly to an appropriate value based on the data
It is also possible to specify.

FIG . 7 shows a sheet feeding device according to the second embodiment .
It shows a schematic configuration. The same parts as in FIG.
The same reference numerals are given, and the description thereof will be omitted as appropriate.
In the paper feeding device of the second reference example, the suction-type transport mechanism 18
, A vacuum motor 51 is directly disposed.
In the vicinity of the uppermost layer of the paper 12, a one-dimensional image
The position sensor 71 in which the image sensor is arranged in the vertical direction is
And the position of the uppermost sheet 12T is determined.
It has become. Also, on the back side of the uppermost sheet 12T,
Is provided with a mark reading sensor 72,
The preprinted type identification mark (not shown)
It can be read. Further, the supply tray 11
Holes (not shown) are drilled at multiple locations of
The optical sensor 73 is arranged so as to look through the hole. This
These optical sensors 73 are used for the sheets stacked on the supply tray 11.
Used to determine the size of paper 12
ing.

FIG . 8 shows the rotation of the sheet feeding device of the second embodiment .
This shows an outline of the road configuration. This figure is the same as FIG.
Portions are assigned the same reference numerals, and these descriptions
Omitted here. In this figure, the ROM 43 connected to the bus 42
A is a program for various controls of the sheet feeding device of this reference example.
Ram is stored. In addition, the input circuit
Sensor 71, mark reading sensor 72, plural optical sensors 7
3 and the operation panel 53 are connected.

FIG . 9 shows an image forming operation using this paper feeder.
Controls the position of the supply tray when the recording of the device is started .
It is a representation of the situation. Start to start recording
When the button is pressed (step S301; Y), the CPU
41 checks the output of the optical sensor 73 and turns them on and off.
The size of the paper 12 is determined based on the information (step
S302). For example, paper is detected at the leading edge of A4 size paper.
The paper is detected at the leading edge of the B5 size paper
The paper 12 contained is B5 size
Is determined.

Next, the CPU 41 operates the mark reading sensor 72.
Check the detection result and if the mark is read
(Step S303; Y), this is decrypted and
Such as thin paper or thin paper
The type of the paper 12 is determined (step S304). Paper 1
2 as if those marks were not printed in advance
If the mark could not be detected (step S3
03; N), set a reference value as a standard value instead
(Step S305). In this case, the operating
Is displayed on the control panel 53, and the type of paper 12
May be input. Also read the mark
Use various sensors such as transmissive optical sensors instead of
And the type of the paper 12 may be directly determined.
No.

Thus, the size and type of the paper 12
(Or equivalent reference value), CP
U41 uses this table to prepare a
To read the optimum position Y _B for (step S3
06). Then, as described with reference to FIG.
Setting the feed tray 11 to the optimum position Y _B (step
S307). Thereafter, the feeding of the paper 12 is started.
And

In the second embodiment, the position sensor 7
1 to adjust the position of the supply tray 11.
However, the contact sensor 33 was used as in the first reference example.
Or a predetermined position with the normal sensor 16 shown in FIG.
After the position is detected, make the final position adjustment of the supply tray.
It is also possible to do so.

Example

In the second reference example, paper is formed using various sensors.
The type and size of the
If you ask them to specify their type and size,
Also set the optimum position Y _B of the feed tray 11 in the
it can. Also, using the operation panel 53 shown in FIG.
Have operators enter these data
Is also possible. Subsequent operations are as described above.
is there.

By the way, in the second reference example, FIG.
To detect the type and size of paper 12 each time recording starts
did. This means that each time paper 12 is fed,
Since the height of 12T is low, a new
And Do records to set the optimum position Y _B each time you start
This is because However, a lot of paper 1 continuously
In the case where the recording operation is performed on the sheet 2, the uppermost sheet 12
In some cases, the height of T falls below the appropriate range.
I will.

FIG . 10 shows the case of such continuous recording.
In this embodiment, the height of the supply tray can be adjusted.
This shows the main part of the control contents of the paper device. This equipment
Paper 12 is fed continuously from the supply tray 11
When issued (step S401), the non-volatile memory 45
To the number of drive pulses for correction corresponding to the thickness of the paper 12
M is read (step S402). And Elevé
The elevator motor 13 is controlled by controlling the
Are supplied with M drive pulses, and the wire 14 is
The supply tray 11 is lifted by winding it by a very small amount.
(Step S403). Thereby, the uppermost sheet 12
T will always be kept at the proper height.

The number of drive pulses M is read in the second reference example.
The mark may be obtained by decrypting the mark.
When the paper tray 12 is set by the
The input may be made from the operation panel 53.

In FIG. 10, a predetermined number of sheets are fed.
The drive pulses for the elevator motor 13 each time the
Although supply is performed, the number of drive pulses given at one time
And supply tray 11 according to the type of paper 12.
Change the number of sheets fed until control is performed
You may do so. Of course, the control of the supply tray 11
The number of sheets fed and the number of drive pulses before
Both can be variably controlled. Also this deformation
The height control of the supply tray 11 according to the example also applies to the present invention.
Of course, it can be done.

[0037]

【The invention's effect】 As described above, the invention of claim 1
According to the paper size and type from the keyboard
Input, so if you want the device to
It is possible to correspond to a new type of paper etc.
And other values such as moisture absorption
It is possible to take detailed measures.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a side surface of a sheet feeding device according to a first reference example of the present invention.

FIG. 2 is a front view showing a main part of a suction-type transport mechanism 18 in the first reference example .

FIG. 3 is a block diagram illustrating a main part of a circuit configuration of a sheet feeding device according to a first reference example ;

FIG. 4 is a flowchart showing the state of initial control when the paper in the supply tray is replaced or replenished in the first reference example .

FIG. 5 is a flowchart showing a state of control of raising and lowering a supply tray after initial control is performed in the first reference example .

FIG. 6 is an explanatory diagram showing an example of the contents of a position calculation table stored in a nonvolatile memory in the first reference example .

FIG. 7 is a schematic configuration diagram illustrating a schematic configuration of a sheet feeding device according to a second reference example .

FIG. 8 is a block diagram illustrating an outline of a circuit configuration of a sheet feeding device according to a second reference example .

FIG. 9 is a flowchart illustrating a state of position control of a supply tray when recording of an image forming apparatus using a sheet feeding device according to a second reference example is started.

FIG. 10 is a flowchart showing the control contents of a sheet feeding device capable of adjusting the height of a supply tray even in continuous printing as an embodiment of the present invention.

FIG. 11 is a schematic configuration diagram illustrating a main part of a conventional sheet feeding device of an air suction type.

[Explanation of symbols]

11 ... supply tray, 12 ... paper, 12T ... top layer paper, 13 ... elevator motor, 14 ... wire,
19: conveyor belt, 33: contact sensor, 41: C
PU, 43, 43A ROM, 44 RAM, 45
…… Non-volatile memory, 51 …… Vacuum motor, 53
... Operation panel 54 Clock circuit 71 Position sensor 72 Mark reading sensor 73 Optical sensor

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B65H 1/14 B65H 3/12 B65H 7/16

Claims (1)

(57) [Claims] 1. A supply tray for storing cut sheets, input means for inputting the size and type of cut sheets stored in the supply tray, elevating means for raising and lowering the supply tray, and the supply tray Paper feed means which is arranged above the paper tray and sucks the uppermost layer of cut paper accommodated therein and adsorbs it to a predetermined portion, and then sends it out of the supply tray; and Interval calculating means for calculating an appropriate distance between the uppermost layer of sheets stored in the supply tray and the predetermined portion based on the type; and elevating means controlling the elevating means to be at the calculated interval. Means.