JP4034277B2 - Automatic sheet feeder - Google Patents

Description

  The present invention relates to an automatic sheet feeding apparatus used for image reading and paper conveyance of a copying machine, a scanner, a facsimile, and a multifunction machine having these functions. In this specification, the “sheet” is a concept including both a document on which a read image is recorded, an original such as a film or a film, and a paper on which the read image is formed.

  In an automatic document feeder (a kind of automatic sheet feeder) equipped with a tray (original placement plate (sheet placement plate)) on which a large amount of originals (sheets) can be set, the document is fed. In order to stabilize the performance, the contact pressure of the paper feed roller with respect to the uppermost document may be appropriately controlled by controlling the position of the document placing plate. In a document feeder that employs such a system, the document placement plate is lowered to the lowest position before the document is set. Then, when a document is set on the document placing plate and the start key of the image forming apparatus is pressed, the document placing plate is moved to a predetermined feeding position and then the document feeding operation is started. Has been made.

In the case of such control, there is a problem that it takes a waiting time until the document is fed because the document placing plate moves from the lowest position to a predetermined feeding position after the start key is pressed. In order to solve such problems, currently, when no document is set, when the document is set on the document placing plate at the lowest position, the presence or absence of this document is detected and the start is started. In general, control is performed to automatically move the document placement plate to a predetermined paper feed position before the key is pressed.
Japanese Patent Laid-Open No. 11-157777

  However, in the case of such control, if the original is reset, or if a large number of originals such as 100 sheets or more are to be set in two steps, the original is set when the original is first set. Since the mounting plate starts to move to a predetermined paper feeding position, there is a problem in operability. In addition, in order to solve this problem, when the user wants to lower the document placing plate to the lowest position, a switch or the like is instructed, and there is a problem in terms of cost and operability. It was. The technique described in Patent Document 1 relates to a paper feeding device that feeds paper. When paper setting is completed, the pickup roller is driven to press the paper against the pickup roller. In this case, the same problem occurs when adding paper.

  The present invention has been made in view of the above points, and in an automatic sheet feeding apparatus capable of placing a large number of sheets, not only can the time for starting the feeding operation after pressing the start key be reduced, It is an object of the present invention to provide an automatic sheet feeder capable of easily performing additional sheet setting.

In order to solve the above-described problems, the present invention provides, as a first solving means related to an automatic sheet feeding apparatus, a sheet placing plate for placing a sheet, and a large amount of moving by placing the placing plate. In the automatic sheet feeding apparatus capable of setting sheets, the control means for controlling the automatic sheet feeding apparatus sets the sheet placing plate according to the amount of sheets set on the sheet placing plate. The uppermost surface is moved to a predetermined standby position for providing a predetermined gap between the sheet feeding roller for feeding the sheet and the uppermost surface of the sheet, and this is detected when a sheet is added. Then, the sheet is further moved so that the uppermost surface of the sheet after the sheet is added becomes the standby position, or further moved so that the sheet placing plate is moved to the lowest position.

Further, as a second solving means related to the automatic sheet feeding device, a sheet placing plate for placing a sheet, a sheet detecting means for detecting presence / absence of a sheet on the sheet placing plate, and the sheet placing A basic position detecting means for detecting that the placing plate is at a basic position for setting a sheet, and a sheet placed on the sheet placing plate comes into contact with the sheet feeding roller and pushes up the sheet feeding roller. , A sheet feeding position detecting means for detecting that the uppermost surface of the sheet placed on the sheet placing plate is at a predetermined sheet feeding position, and moving the sheet placing plate between the sheet feeding position and the basic position. In an automatic sheet feeding device of an image forming apparatus having a driving unit, the control unit of the image forming apparatus controls the driving unit so that when a sheet is not set on the sheet placing plate, Mounted on the sheet When the upper surface of the plate is moved to the basic position and the sheet detecting means detects that the sheet is set on the sheet mounting plate, the uppermost surface of the sheet mounted on the sheet mounting plate Is moved to a predetermined sheet feeding position, and a predetermined gap is provided between the sheet feeding roller and the uppermost surface of the sheet in the basic position direction by a certain distance from the position at which the sheet feeding position is detected. When the sheet is moved to the standby position, which is a stop position, and the start key is pressed in this state, the uppermost surface of the sheet placed on the sheet placement plate is positioned at the sheet feeding position. And the sheet feeding operation is started.

Further, as a third solving means relating to the automatic sheet feeding apparatus, in the second solving means, the control means is configured such that the uppermost surface of the sheet placed on the sheet placing plate is at the standby position. When the detection signal is output by the paper feed position detecting means, the upper surface of the sheet placing plate is moved to the basic position and held in this state until the start key is pressed. Is moved to the paper feeding position to start the paper feeding operation.

Further, as a fourth solving means relating to the automatic sheet feeding apparatus, in the second solving means, the control means is configured such that the uppermost surface of the sheet placed on the sheet placing plate is at the standby position. When the detection signal is output by the sheet feeding position detecting means, the top surface of the sheet including the additional sheet placed on the sheet placing plate is moved to the standby position, and in this state, the start key Is held until the sheet is pressed, and the sheet placement plate is moved to the sheet feeding position by a start key ON to start the sheet feeding operation.

Further, as a fifth solving means related to the automatic sheet feeding device, a sheet placing plate for placing a sheet, a sheet detecting means for detecting presence or absence of a sheet on the sheet placing plate, and the sheet placing A basic position detecting means for detecting that the placing plate is at a basic position for setting a sheet, and a sheet placed on the sheet placing plate comes into contact with the sheet feeding roller and pushes up the sheet feeding roller. , A sheet feeding position detecting means for detecting that the uppermost surface of the sheet placed on the sheet placing plate is at a predetermined sheet feeding position, and moving the sheet placing plate between the sheet feeding position and the basic position. In the automatic sheet feeding device of the image forming apparatus having a driving unit, the image forming apparatus further includes sheet position detecting means for detecting that the uppermost surface of the sheet placed on the sheet placing plate is at a predetermined position, The control means of When the sheet is not set on the sheet placing plate by controlling the driving means, the sheet placing plate is moved so that the upper surface of the sheet placing plate is at the basic position, and the sheet is detected by the sheet detecting means. When it is detected that the sheet is placed on the sheet placement plate, the sheet placement is performed so that the uppermost surface of the sheet placed on the sheet placement plate comes to a predetermined position detected by the sheet position detection means. The rest is moved to the basic position in the direction of the basic position by a certain distance from the position detected by the sheet position detecting unit, and then a standby position that is a stop position for providing a predetermined gap between the sheet feeding roller and the uppermost surface of the sheet. When the start key is pressed in this state, the sheet placing plate is moved until the uppermost surface of the sheet placed on the sheet placing plate is located at the sheet feeding position. So, it is characterized in that to start the paper feed operation.

Further, as a sixth solving means relating to the automatic sheet feeding apparatus, in the fifth solving means,
When the sheet position detection unit is turned on, the control unit moves the sheet placed on the sheet placing plate to the standby position so that the uppermost surface of the sheet comes and keeps this state, and a certain time has elapsed. If the sheet position detecting means is not turned on later, the sheet placement plate is once moved to the position detected by the sheet position detecting means, and then the state is maintained after moving to the standby position. It is characterized by that.

Further, as a seventh solving means relating to the automatic sheet feeding device, the fifth or sixth solving means described above.
In the stage, the predetermined position detected by the sheet position detecting means is in the basic position direction from the position of the lowermost surface of the paper feed roller and in the paper feed position direction from the standby position.

  According to the present invention, a sheet placing plate for placing sheets is provided, and feeding is started in an automatic sheet feeding device that can set a large number of sheets by moving the sheet placing plate. After the operation is performed (after the start key is pressed), it is possible to shorten the time until the sheet feeding operation is started, and it is possible to easily perform additional sheet setting.

Next, embodiments of the present invention will be described with reference to the drawings.
In the drawings, common parts are denoted by common reference numerals.
[Outline of the present invention]
In an automatic sheet feeding apparatus equipped with a tray (sheet placing plate) capable of setting a large amount of sheets, the sheet placing plate is positioned according to the amount of sheets set, As a result, when a sheet is added by being moved to a predetermined standby position L3 for providing a predetermined gap between the sheet feeding roller for feeding the sheet and the top surface of the sheet, the sheet is added. Detect the amount of sheet (thickness, uppermost position of the sheet) and move the sheet placement plate after adding the sheet to the basic position L1 or move the position of the uppermost surface of the sheet to the standby position L3. Thus, it is possible to easily set the sheet to be added while keeping the time from the start instruction by the user to the start of the sheet feeding operation short.

Here, the basic position L1, the paper feed position L2, and the standby position L3 will be described with reference to FIG.
In the figure, 2 is a document placing plate (sheet placing plate), 3 is a document, 4 is an additional document, and 5 is a paper feed roller.
The basic position L1 is the position of the upper surface of the document placing plate 2 at the lowest position when the document (sheet) 3 is not set. The sheet feeding position L2 is a position where the uppermost surface of the document 3 is fed (sent out) by receiving an appropriate contact pressure from the sheet feeding roller 5 at this position. The standby position L3 is a position closer to the basic position L1 (a position below the paper feed position L2 in the figure), and a predetermined gap is provided between the uppermost surface of the original moved to the standby position L3 and the paper feed roller 5. This is the position to generate.

  As shown in the figure, the lower end of the paper feed roller 5 is lowered by “b” from the paper feed position L2 in a state where it does not come into contact with the original 3, the original placement plate 2 is lifted up, and the uppermost surface of the original is When the sheet is moved up to the sheet feeding position L2 (at this time, the lower end of the sheet feeding roller 5 is at the sheet feeding position L2), the uppermost document uppermost surface receives an appropriate contact pressure as described above. The paper feed roller 5 is configured to move further upward than the paper feed position L2. For example, in this embodiment, the paper feed roller 5 can be moved by a distance that is 2/3 of the radius of the paper feed roller 5.

In the example shown in the figure, the standby position L3 is located “a” below the position of the lower end of the paper feed roller 5 when not in contact with the document 3. That is, there is a gap of “a” between the uppermost surface of the document at the standby position L3 and the lower end of the paper feed roller 5. Due to the presence of this gap, the additional original 4 can be easily inserted. When the thickness of the additional document 4 satisfies the following conditions, it can be inserted between the top surface of the document and the paper feed roller 5 as it is.
Condition: Document thickness (d) <feed roller diameter (diameter) (c) × 2/6 + setting gap (a)
For example, when a = 3 mm, b = 3 mm, and c = 25 mm, the upper limit of d is 11.3 mm (corresponding to about 100 originals). In the present invention, additional additional documents 4 can be added by the control described later.

Next, an image forming apparatus according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 2 is a block diagram illustrating a configuration of an image forming apparatus (for example, a multifunction machine having functions of a copying machine, a facsimile machine, etc.) according to the present embodiment. FIG. 3 shows a mechanism configuration (schematic) of the image forming apparatus.
The image forming apparatus 1 of the present embodiment has the same basic configuration as a conventional image forming apparatus, and includes a control unit 10, a storage unit 20, a scanner unit 30, an image forming unit 40, an operation unit 50, a display unit 60, The notification unit 70 is generally configured. The control unit 10, the storage unit 20, a part of the scanner unit 30, most of the image forming unit 40, the operation unit 50, the display unit 60, and the notification unit 70 are included in the main body 100.

The control unit 10 controls each unit of the image forming apparatus 1. The image forming apparatus 1 of the present embodiment can reduce the time from when the start key is pressed until the paper feeding operation is started, in addition to the same function as the conventional image forming apparatus. In order to make it possible to easily set an additional document, unique control is performed on the automatic document feeder (described later).
The storage unit 20 stores a control program executed by the control unit 10 and various data. Note that an area (image memory) for storing image data read by the scanner unit 30 is set in the storage unit 20.

  The scanner unit 30 is a portion that reads a document set on a document table, and is equipped with an automatic document feeder 30b (described below) that sequentially conveys a plurality of documents to the document table. The scanner unit 30 has a function of detecting the length in the width direction (main scanning direction) of the original paper and the length in the paper feeding direction (sub-scanning direction), that is, the paper size of the original.

  The image forming unit 40 includes a sheet feeding unit that feeds a sheet material that is printing paper, a transfer unit that performs a transfer process of a toner image onto the sheet material, and a fixing unit that performs a fixing process of a toner image transferred to the sheet material. And a finisher 40a (described below) that discharges the sheet material after fixing, and performs a series of processes related to the image forming process. For example, when copying, the scanner unit 30 reads a document set on a document table, supplies the image data to the image forming unit 40, and the image forming unit 40 performs an image forming process according to the image data. . The paper feed unit includes a paper feed stage for setting cut paper, and the sheet material of the selected paper feed stage is fed. The finisher 40a is a device that discharges the fixed sheet material to a discharge tray provided in the finisher 40a. The finisher 40a mechanically performs sorting of sheets at the time of sorting, reverse discharge of sheets, and the like.

The operation unit 50 includes various keys including a start key, a touch panel, and the like for the user to input operation commands and settings to the image forming apparatus 1.
The display unit 60 is a display unit that displays a processing status in the image forming apparatus 1 and setting information input from the operation unit 50. A touch panel that constitutes the operation unit 50 is provided on the surface of the display unit 60. .
The notification unit 70 emits a notification sound (buzzer sound, melody, etc.) for abnormality notification or the like.

  As shown in FIG. 3, the automatic document feeder 30b sequentially takes in the documents 3 placed on the document placing plate (not shown in FIG. 3), and the document on which the document reading unit 30a is installed. The paper is fed to the table, and the read original is discharged to the original discharge unit 30b-3. Further, the automatic document feeder 30b can also feed the document to the document table by reversing the document through the document reversing path 30b-2 by the document reversing unit 30b-1. The automatic document feeder 30b is provided with the following sensors and a drive unit for moving the document placement plate between the paper feed position L2 and the basic position L1 (all of them). Not shown). The position referred to here is the position (distance) from the portion where the document placing plate is installed in the automatic document feeder 30b.

The control unit 10 includes a memory, a CPU (central processing unit), and the like, and loads a program (not shown) for realizing each function of the control unit 10 into the memory and executes the program. Functions shall be realized.
The storage unit 20 is configured by a nonvolatile recording device such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) or a hard disk, and the display unit 60 is configured by a CRT (Cathode Ray Tube) or a liquid crystal display device.

Here, the control of the automatic document feeder 30b will be described in more detail.
In the automatic document feeder 30b, a sensor S0 (document detection means) for detecting the presence / absence of a document on the document placement plate and the upper surface of the document placement plate are at a basic position L1 for setting the document. A sensor S1 (basic position detecting means) for detecting the sheet feed position, and a paper feed position detecting means for detecting that the uppermost surface of the document placed on the document placing plate is at a predetermined paper feed position L2. A sensor S <b> 2 (for example, a switch) is provided to detect the document placed on the document placing plate when it comes into contact with the paper feed roller and pushes up the roller.

  In the automatic document feeder 30b, when an original is not set on the original plate, the upper surface of the original plate is controlled to move to the basic position L1, and the original is set by the sensor S0. When this is detected, the document placement plate is moved to the paper feed position L2. When the sensor S2 detects that the uppermost surface of the document has reached the paper feed position L2, the document placing plate is moved in the direction of the basic position L1 by a certain distance from the position and stopped. In this way, the position of the uppermost surface of the original at this time is controlled to be the above-described standby position L3.

  As a specific control method, as an example in which the document placement plate is driven by a drive unit including a stepping motor, the document placement plate is moved in the L1 direction from the state in which the sensor S2 is ON (ON when detected). And is stopped when driven by a predetermined number of pulses from the time point when the sensor S2 is turned off (at this time, the position of the uppermost surface of the document placed on the document placement plate is the standby position L3). .

In this state, if the start key is pressed, the document placement plate is moved to the paper feed position L2, and then the paper feed operation is started.
By the above control, a predetermined gap is secured between the paper feed roller and the uppermost surface of the document before the start key is pressed. It becomes possible.

  In the present embodiment, when an additional document is set when the uppermost surface of the document placed on the document placing plate is at the standby position L3, if this document group is thick enough to push up the paper feed roller (feed) In the case of setting an additional original in an amount exceeding the range of the gap between the paper roller and the uppermost surface of the original document), the paper supply roller is pushed up and comes to a position beyond the paper supply position L2. At that time, a detection signal is output by the sensor S2 (paper feed position detecting means), and as a subsequent control corresponding to this, one of the following two types of control is performed.

[Control 1]
The control unit 10 moves the upper surface of the document placing plate to the basic position L1 (until it is detected by the sensor S1) in accordance with the detection signal of the sensor S2. This makes it possible to easily set an additional document. This state is maintained until the start key is pressed, and the document placement plate is moved until the uppermost surface of the document placed on the document placement plate reaches the paper feed position L2 (until it is detected by the sensor S2). Move and start the paper feeding operation.

[Control 2]
In response to the detection signal of the sensor S2, the control unit 10 moves the document placing plate so that the uppermost surface of the document after the document is added becomes the standby position L3 (see FIG. 7). This state is maintained until the start key is pressed. When the start key is pressed, the uppermost surface of the document placed on the document placing plate reaches the paper feed position L2 (until it is detected by the sensor S2). ) Move the document placing plate and start the paper feeding operation.

  Here, a series of control processes executed by the control unit 10 will be described with reference to FIGS. 4 to 6 include the control 1 described above, and FIGS. 8 to 10 include the control 2 described above. First, the control procedure shown in FIGS.

First, it is determined whether or not the upper surface of the document placing plate is at the basic position L1 (step S101). When the upper surface of the document placing plate is at the basic position L1, the above-described sensor S1 outputs a detection signal. The control unit 10 makes this determination based on this detection signal.
Here, if the upper surface of the document placement plate is not at the basic position L1, “No” is determined in the determination in step S101, and the process proceeds to step S102. In step S102, the document placement plate is moved in the basic position L1 direction. Let The control processing in steps S101 to S102 is repeated until the upper surface of the document placement plate reaches the basic position L1, that is, until a detection signal is output by the sensor S1, and as a result, the upper surface of the document placement plate is Come to position L1.

When the upper surface of the document placing plate comes to the basic position L1, “YES” is determined in the determination in step S101, and the process proceeds to step S103.
In step S103, it is determined whether or not there is a document on the document placement plate. When a document is set on the document placing plate, the sensor S0 described above outputs a detection signal. The control unit 10 makes this determination based on this detection signal.
When the document is set on the document placing plate, “YES” is determined in the determination in step S103, and the process proceeds to step S104.

  Then, in the loop of steps S104 and S105, the document placement plate is moved until the uppermost surface of the document set on the document placement plate reaches the paper feed position L2. When the uppermost surface of the document set on the document platen comes to the paper feed position L2, the above-described sensor S2 outputs a detection signal, and in response to this, the control unit 10 determines “YES” in the determination of step S105. judge. Then, the process proceeds to step S106.

  In step S106, the document placement plate is moved until the uppermost surface of the document set on the document placement plate reaches the standby position L3. Here, as described above, as an example of the case where the document placement plate is driven by the drive unit including the stepping motor as described above, the document placement plate is moved in the L1 direction from the state where the sensor S2 is ON, and the sensor S2 is Control is performed to stop at the time of driving for a predetermined number of pulses from the time of turning OFF.

  In step S107, it is determined whether or not the start key is pressed. If the start key is OFF, “NO” is determined, and the process proceeds to step S108. In step S108, it is determined whether the sensor S2 is turned on. When the sensor S2 is OFF, it is determined as “NO”, and the process waits until the start key is turned ON or the sensor S2 is turned ON by the determination processing of these steps S107 and S108.

Here, it is assumed that the start key is pressed (start key ON). Then, YES is determined in the determination in step S107, and the process proceeds to step S111.
Then, in the loop of steps S111 and S112, the document placement plate is moved until the uppermost surface of the document set on the document placement plate reaches the paper feed position L2, similarly to steps S104 and S105 described above. When the uppermost surface of the document set on the document platen comes to the sheet feeding position L2, “YES” is determined in the determination in step S112, the process proceeds to step S113, and the sheet feeding operation is started in step S113. .

On the other hand, if the detection signal is output from the sensor S2 after the process of step S106 and before the start key is pressed, that is, if the sensor 2 is turned on by adding a document, “NO” in step S107, step S108. Is determined as “YES”, and the process proceeds to Step S109.
Then, in the loop of steps S109 and S110, the original platen is moved until the upper surface of the original platen comes to the basic position L1. When the upper surface of the document placing plate comes to the basic position L1, the sensor S1 outputs a detection signal. In response to this, the control unit 10 determines “YES” in the determination in step S114, and returns to step S107. And the process after step S107 is performed.

Next, the processing procedure shown in FIGS.
The control processing from step S201 to S206 shown in FIG. 8 is the same as the control processing from step S101 to S106 shown in FIG.
When the control processing up to step S206 is completed, it is determined in step S207 whether the sensor S2 is not ON and a predetermined time has elapsed. Regarding the elapse of the predetermined time, the control unit 10 measures the time using a timer provided therein, and a predetermined time determined separately from the time when the uppermost surface of the document set on the document placing plate reaches the standby position L3. It is determined whether or not it has passed.

If the predetermined time has elapsed and it is determined “YES” in step S207, the process proceeds to step S208.
In the loop of steps S208 and S209, the original platen is moved until the uppermost surface of the original set on the original platen comes to the paper feed position L2. When the uppermost surface of the document set on the document platen comes to the paper feed position L2, the sensor S2 outputs a detection signal, and in response to this, the control unit 10 determines “YES” in the determination in step S209. The process proceeds to step S210.
In step S210, the document placement plate is moved in the same manner as in step S106 described above until the uppermost surface of the document set on the document placement plate reaches the standby position L3.

  In the processing of steps S207 to S210, when the sensor S2 is not turned on / off for a certain period of time, as a standby position confirmation operation (reset operation), the lift is temporarily raised to the upper limit paper feed position L2, and then waits again. It is moved to position L3. This is because when there is no additional document and the paper feed roller is inadvertently touched and lifted down, it may wait at a position lower than the original standby position L3. It is an operation to do. Further, depending on the thickness of the additional document, the position of the uppermost surface of the additional document may not be the standby position L3 in one lift-down. After the processing in steps S207 to S210, the position of the top surface of the additional document can be accurately set as the standby position L3.

  In a succeeding step S211, it is determined whether or not the sensor S2 is turned on. If the sensor S2 is OFF, it is determined “NO”, and the process proceeds to step S212. In step S212, it is determined whether or not the start key has been pressed. If the start key has not been pressed in step S212, the process returns to step S207, and the control processing in steps S207 to S212 is repeatedly waited until the sensor S2 is turned on or the start key is turned on. Of course, when the predetermined time elapses during this period, the resetting operation to the standby position L3 is performed.

  Here, it is assumed that the start key is pressed (start key ON). Then, YES is determined in the determination in step S212, and the process proceeds to step S213. The processes after step S213 (S213 to S215) are the same as the processes of steps S111 to S113 shown in FIG. 6 described above (the description is omitted).

  On the other hand, if a detection signal is output from the sensor S2 before the start key is pressed, that is, if the sensor S2 is turned ON by adding a document, “YES” is determined in the step S211, and the process returns to the step S206, and then the step S206. With this control, the document placement plate is moved until the top surface of the added document reaches the standby position L3 (at this time, the document placement plate has moved to a new position). Thereafter, the control processing after step S207 described above is executed.

  In the control procedure shown in FIGS. 8 to 10, when the sensor S2 is repeatedly turned on / off at the paper feed position L2, the original platen is moved toward the basic position by a predetermined distance from the time when the sensor S2 is turned off. Since the moving operation is repeatedly performed, in some cases, it is conceivable to lift down to the basic position L1. Therefore, although not in the flowcharts shown in FIGS. 8 to 10, the sensor S1 detects the arrival of the upper surface of the document placing plate at the basic position L1, and when it reaches, the lift-down operation is stopped.

[Other Embodiments]
In the present embodiment, the automatic document feeder 30b of the image forming apparatus 1 described above has a sensor S3 (document position detecting means) for detecting that the uppermost surface of the document placed on the document placing plate 2 is at a predetermined position. ) Is further provided. Other configurations are the same as those of the image forming apparatus 1 described above.
The detection position of the uppermost surface of the document by the sensor S3 is set so as to be positioned in the basic position L1 direction by a predetermined distance from the paper feeding position L2. The standby position L3 is further by a predetermined distance from the detection position of the sensor S3. It is set on the position L1 direction side.

  When no document is set on the document placement plate, when it is detected that the document is set on the document placement plate whose upper surface is at the basic position L1, the document placement plate is moved to the standby position L3. And hold in this state. In this state, when the start key is pressed, the paper feeding operation after the document placing plate is moved to the paper feeding position L2 is started. On the other hand, if an additional document is set and the sensor S3 is turned on before the start key is pressed, the document placement plate moves in the basic position L1 direction until the uppermost surface of the additional document reaches the standby position L3. And hold in this state.

FIG. 11 shows the positional relationship of the document placing plate 2, the document 3, the additional document 4, the paper feed roller 5, and the actuator 6 including the sensor S3.
FIG. 11 is the same as that shown in FIG. 1 except for the actuator 6. The sensor S3 detects when the lower end of the actuator 6 has moved to the L4 position and turns ON (outputs a detection signal). When the additional original 4 is added, the actuator 6 is lifted, and the lower end of the actuator 6 moves above L4 to detect that the original has been added. In the example shown in FIG. 11, the L4 position is set to the position of the lower end of the paper feed roller 4 when not in contact with the document 3.

With this configuration, when the paper feed roller diameter (diameter) is 25 mm (depending on the length of the actuator 6), about 200 originals (about 20 mm thick) can be easily added. .
In the example shown in FIG. 11, the actuator 6 is used. However, any actuator that can detect the uppermost surface of the document 3 set on the document placing plate 2 at the L4 position may be used. This detection may be performed.

Next, control processing in the image forming apparatus 1 including the automatic document feeder 30b configured as described above will be described with reference to FIGS.
The control processing from step S301 to S306 shown in FIG. 12 is the same as the control processing from step S101 to S106 shown in FIG. 1, but from the movement of the document placement plate in the direction of paper feed position L2 to the standby position L3. The movement is switched based on the position detection of the uppermost surface of the document by the sensor S3 in step S305, instead of the detection by the sensor S2 in step S105 described above. When the uppermost surface of the document added in the present embodiment is moved to the standby position L3, it is as shown in FIG.

The subsequent control processes in steps S307 to S312 are the same as the control processes in steps S207 to S212 shown in FIG. However, in steps S208 to S209 described above, the uppermost surface of the document set on the document placing plate is moved until it reaches the paper feed position L2. However, in steps S308 to S309 in this embodiment, the sensor S3 is turned on. Until the uppermost surface of the document set on the document placement plate reaches the L4 position (located on the basic position L1 side from the paper feed position L2). In addition, in step S211, the addition of the document is detected by the sensor S2, whereas in the present embodiment, the addition is detected by the sensor S3 in step S311.
The subsequent control processing of steps S313 to S315 is the same as that of steps S213 to S215 shown in FIG.

  In this embodiment, an actuator 6 including a sensor S3 is further provided in the configuration of the previous embodiment, but the detection position of this sensor S3 is in the basic position L1 direction from the lowermost surface of the paper feed roller 5. Therefore, it is possible to shorten the time until the uppermost surface of the document set on the document placement plate is moved to the standby position L3 by lifting and lowering the document placement plate. Also, it is easier to add more originals than in the previous embodiment.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes a configuration and the like that do not depart from the gist of the present invention. Needless to say. In the above description, the automatic document feeder of the image forming apparatus has been described. However, in addition to the automatic document feeder of the image forming apparatus, a large amount of paper such as an automatic paper feeder that automatically conveys paper to the image forming unit. The present invention can be applied to a paper feeding device that transports the paper. The standby position L3 may be changeable by a predetermined operation using the operation unit 50. In this way, the number of originals (sheets) that can be added and the time from when the start key is pressed to when the paper feeding operation starts can be set to an optimum relationship desired by the user.

It is a figure explaining the basic position L1, the paper feed position L2, and the standby position L3. 1 is a block diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a mechanism configuration of the image forming apparatus according to the embodiment. It is a flowchart which shows the control processing (control 1) of the embodiment. It is a flowchart which shows the control processing (control 1) of the embodiment. It is a flowchart which shows the control processing (control 1) of the embodiment. It is a figure which shows the state after a document addition. It is a flowchart which shows the control processing (control 2) of the embodiment. It is a flowchart which shows the control processing (control 2) of the embodiment. It is a flowchart which shows the control processing (control 2) of the embodiment. FIG. 6 is a diagram illustrating a basic position L1, a paper feed position L2, a standby position L3, and a position L4 detected by a sensor S3. It is a flowchart which shows the control processing of other embodiment. It is a flowchart which shows the control processing of other embodiment. It is a flowchart which shows the control processing of other embodiment. It is a figure which shows the state after a document addition.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 2 ... Document placing plate (sheet placing plate)
3 ... Original (sheet)
4. Additional manuscript (additional sheet)
5 ... feed roller 6 ... actuator 10 ... control unit (control means)
DESCRIPTION OF SYMBOLS 20 ... Memory | storage part 30 ... Scanner part 30a ... Document reading part 30b ... Automatic document feeder (automatic sheet feeder)
30b-1 ... Document reversing unit 30b-2 ... Document reversing path 30b-3 ... Document discharging unit 40 ... Image forming unit 40a ... Finisher 50 ... Operation unit 60 ... Display unit 70 ... Notification unit 100 ... Main body

Claims (6)

A sheet placing plate for placing a sheet and a sheet feeding roller for feeding a sheet placed on the sheet placing plate are provided, and a large amount is obtained by moving the sheet placing plate. In the automatic sheet feeding device that can set the sheet of
A paper feed position detecting means for detecting that the uppermost surface of the sheet placed on the sheet placing plate is at a predetermined paper feed position by pushing up the paper feed roller;
The sheet placement plate has a predetermined position for providing a predetermined gap between the sheet feeding position and the top surface of the sheet according to the amount of sheets set on the sheet placement plate. Control means for moving to the standby position of
When the control unit detects that the sheet feeding roller is pushed up by the sheet feeding position detecting unit by adding a sheet in a state where the position of the uppermost surface of the sheet is the standby position. The sheet upper surface after the sheet addition is further moved so as to be the standby position, or the sheet placement plate is further moved so as to be the lowest position.
An automatic sheet feeding device characterized by that. A sheet placing plate for placing a sheet; sheet detecting means for detecting the presence or absence of a sheet on the sheet placing plate; and detecting that the sheet placing plate is in a basic position for setting a sheet A basic position detecting means that contacts the sheet feeding roller with the sheet placed on the sheet placing plate and pushes up the sheet feeding roller so that the uppermost surface of the sheet placed on the sheet placing plate is In an automatic sheet feeding apparatus of an image forming apparatus, comprising a sheet feeding position detecting means for detecting that the sheet feeding position is at a predetermined sheet feeding position, and a driving means for moving the sheet placing plate between the sheet feeding position and the basic position.
When the sheet is not set on the sheet placing plate by controlling the driving unit, the sheet is moved so that the upper surface of the sheet placing plate becomes a basic position, and the sheet is detected by the sheet detecting unit. When it is detected that the sheet is set on the loading plate, the position where the uppermost surface of the sheet loaded on the sheet loading plate is moved to a predetermined feeding position and the arrival at the feeding position is detected. When moving to the basic position direction from the feed roller and the top surface of the sheet to a standby position that is a stop position for providing a predetermined gap, and the start key is pressed in this state, Control means for starting the sheet feeding operation by moving the sheet placing plate until the uppermost surface of the sheet placed on the sheet placing plate is located at the sheet feeding position;
When the detection signal is output by the paper feed position detection unit when the uppermost surface of the sheet placed on the sheet placement plate is at the standby position, the control unit moves the upper surface of the sheet placement plate. Move to the basic position, hold in this state until the start key is pressed, move the sheet placing plate to the paper feeding position by turning on the start key, and start the paper feeding operation.
An automatic sheet feeding device characterized by that. A sheet placing plate for placing a sheet; sheet detecting means for detecting the presence or absence of a sheet on the sheet placing plate; and detecting that the sheet placing plate is in a basic position for setting a sheet A basic position detecting means that contacts the sheet feeding roller with the sheet placed on the sheet placing plate and pushes up the sheet feeding roller so that the uppermost surface of the sheet placed on the sheet placing plate is In an automatic sheet feeding apparatus of an image forming apparatus, comprising a sheet feeding position detecting means for detecting that the sheet feeding position is at a predetermined sheet feeding position, and a driving means for moving the sheet placing plate between the sheet feeding position and the basic position.
When the sheet is not set on the sheet placing plate by controlling the driving unit, the sheet is moved so that the upper surface of the sheet placing plate becomes a basic position, and the sheet is detected by the sheet detecting unit. When it is detected that the sheet is set on the loading plate, the position where the uppermost surface of the sheet loaded on the sheet loading plate is moved to a predetermined feeding position and the arrival at the feeding position is detected. When moving to the basic position direction from the feed roller and the top surface of the sheet to a standby position that is a stop position for providing a predetermined gap, and the start key is pressed in this state, Control means for starting the sheet feeding operation by moving the sheet placing plate until the uppermost surface of the sheet placed on the sheet placing plate is located at the sheet feeding position;
When the detection signal is output by the paper feed position detection unit when the uppermost surface of the sheet placed on the sheet placement plate is at the standby position, the control unit places the sheet on the sheet placement plate. The uppermost surface of the sheet including the added sheet is moved so as to be the standby position, and held in this state until the start key is pressed, and the sheet placement plate is moved to the sheet feeding position by the start key ON, Start the paper feeding operation,
An automatic sheet feeding device characterized by that. A sheet placing plate for placing a sheet; sheet detecting means for detecting the presence or absence of a sheet on the sheet placing plate; and detecting that the sheet placing plate is in a basic position for setting a sheet A basic position detecting means that contacts the sheet feeding roller with the sheet placed on the sheet placing plate and pushes up the sheet feeding roller so that the uppermost surface of the sheet placed on the sheet placing plate is In an automatic sheet feeding apparatus of an image forming apparatus, comprising a sheet feeding position detecting means for detecting that the sheet feeding position is at a predetermined sheet feeding position, and a driving means for moving the sheet placing plate between the sheet feeding position and the basic position.
Sheet position detecting means for detecting that the uppermost surface of the sheet placed on the sheet placing plate is at a predetermined position ;
When the sheet is not set on the sheet placing plate by controlling the driving unit, the sheet is moved so that the upper surface of the sheet placing plate becomes a basic position, and the sheet is detected by the sheet detecting unit. When it is detected that the sheet is placed on the placement plate, the sheet placement is performed so that the uppermost surface of the sheet placed on the sheet placement plate comes to a predetermined position detected by the sheet position detection unit. A standby position that is a stop position for moving a plate and then providing a predetermined gap between the sheet feeding roller and the uppermost surface of the sheet in a basic distance direction from the position detected by the sheet position detection unit by a certain distance. is moved up, when the start key is pressed in this state, moving the seat mounting plate to the uppermost surface of the sheet placed on the sheet placing plate is positioned in the sheet feeding position And a control means for starting the paper feed operation,
The control means is placed on the sheet placement board when a detection signal is output by the sheet position detection means when the uppermost surface of the sheet placed on the sheet placement board is at the standby position. The uppermost surface of the sheet including the additional sheet is moved so as to be in the standby position. In this state, the sheet is held until the start key is pressed. When the start key is turned on, the sheet placement plate is moved to the sheet feeding position. Start paper movement ,
An automatic sheet feeding device characterized by that. The controller is
When the sheet position detection means is turned on, the sheet is placed so that the uppermost surface of the sheet placed on the sheet placement plate comes to the standby position, and this state is maintained. If the sheet position detecting means is not turned on, the sheet placement plate is once moved to a position detected by the sheet position detecting means, and then moved to the standby position, and then the state is maintained. The automatic sheet feeding apparatus according to claim 4. 5. The predetermined position detected by the sheet position detection unit is in a basic position direction from a position of a lowermost surface of the paper feed roller and in a direction of the paper feed position from the standby position. Item 6. The automatic sheet feeder according to Item 5.

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