JPH08290856A - Automatic document feeding device - Google Patents

Abstract

PURPOSE: To provide a means for preventing overall slow down of processing speed of a ream of copies as discharge speed of the documents is influenced by carrier speed of the following copies in a 'quick reading type' automatic document feeding device(ADF). CONSTITUTION: The device is constituted to drive a sheet discharge roller 117 at the possible highest speed of a carrier motor 128 when a copy detection sensor 111 judges a sheet as the last sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder (so-called "ADF") in an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, in an automatic document feeder of this type, when an image forming apparatus, for example, an original set on a platen of a copying machine main body is read by the main body, the next original is set on the platen. , The scanned original is moved from the platen, and when it reaches the paper ejection section, the paper ejection drive system is configured to eject the paper, and the paper ejection drive system does not affect the operating conditions without being affected by other driving. No matter what,
The same control is always performed.

[0003]

However, in a so-called "flow-reading type" automatic document feeder in which the transport drive system and the drive system of the discharge unit are the same during reading, the discharge speed of the original is the next original. However, there is a problem in that the sheet discharge speed becomes slower as the conveying speed becomes slower, and the series of document processing speed becomes slower as a whole, because of the influence of the conveying speed.

The present invention has been made in view of the above-mentioned problems, and speeds up the processing speed of a series of originals by maximizing the discharge speed of the final paper which is not affected by the transport speed of the next original. The purpose is to provide means for

[0005]

Therefore, according to the present invention, in an automatic document feeder for exposing a document while conveying the document, a speed-switchable conveying means, a final paper detecting means, and a paper ejection drive are provided. And a means for operating the discharge driving means at a maximum speed possible by the conveying means to perform discharge control of the final paper when the output of the detection means determines that the final paper is the final paper. By doing so, the above object is achieved.

[0006]

With the above-described structure of the present invention, the discharge speed of a document is not affected by the transport speed of the next document, so that the processing speed of a series of documents can be increased and the processing time can be shortened.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail based on embodiments: FIG. 1 is a schematic sectional view of an embodiment of an automatic document feeder (ADF) for an image forming apparatus (copier) according to the present invention. The figure is shown. FIG. 2 is an enlarged view of the paper discharge tray portion in FIG.

A. Configuration In FIGS. 1 and 2, the ADF 100 is equipped with a document stacking table 120 on which a document stack S is set. 20 in the figure
Reference numeral 0 is an image forming apparatus (copier) main body, 201 is a light source, and 20 is a light source.
Reference numeral 2 indicates a platen glass.

Further, on the document table 120, a part of the feeding means and the document detection sensor 111, the first sensor 111, are arranged in the longitudinal direction of the document transportation.
A document size detection sensor 125, a second document size detection sensor 126, and a third document size detection sensor 127 are provided. This feeding means includes a conveyance roller 119, a separation roller 128, a separation / conveyance motor (not shown) (which will be described later with reference to FIG. 5), a registration roller 118, a conveyance roller 117, a registration sensor 112, a paper ejection sensor 113, and a shutter 11.
5, weight 116 and the like.

Here, by pulling a shutter solenoid (not shown), the shutter 115 is pulled up and the weight 11 is pulled up.
Remove 6 Then, the transport roller 119 and the separation roller 1
28 is rotated in the normal direction by the separation / conveyance motor (not shown) to separate the originals one by one from the lowermost part of the original stack S on the original table 120.

Further, the registration roller 118 and the paper discharge roller 117 reversely rotate the separation / conveyance motor to read the original on the sheet path a while conveying the original at the exposure / reading position through the sheet path b. And then
The document is conveyed to the sheet path c, and the document is discharged onto the discharge tray 121 by the discharge roller 117. Reference numeral 114 denotes a sheet detection sensor.

Further, in FIG. 2, the partition lever 123
Is a partition motor (not shown) shown in FIG.
Thus, the document stack S is placed on the uppermost surface. After that, when the original stack below the partition lever 123 is removed, the original stack falls by its own weight and returns to the initial position. The partition lever sensor 124 detects whether or not the partition lever 123 is in the initial position. 122 is the ADF 100
It is a display unit described later provided on the cover of.

B. Block Diagram of Control Device FIG. 5 shows an automatic document feeder (ADF) 100 according to this embodiment.
3 is a block diagram showing a circuit configuration of the control device 500 of FIG.
Central processing unit (CPU) 501, read only memory (ROM) 502, random access memory (RA
M) 503, an output port 504, an input port 505, and the like.

The ROM 502 stores a control program, and the RAM 503 stores input data and work data. The output port 504 has a separate
The conveyance motor 128, the weight / shutter solenoid drive means 129, the partition lever motor 130, etc. are connected,
The input port 505 has a document size detection sensor 125-
127 and the like are connected, and the CPU 501 controls each unit connected via the bus according to a control program stored in the ROM 502. Further, the CPU 501 performs serial communication with the CPU of the copying machine main body (reader unit) (not shown), and exchanges control data with the main body (reader unit).

C. Control Operation (a) The control operation sequence of the ADF 100 in this embodiment will be described with reference to the flowchart of FIG.
When the CPU 501 of the apparatus 100 receives a document transport start signal sent from the copying machine main body 200 to the first document of the document stack S, it performs a document transport start preprocessing described later in FIG. 3 (step S4000). Next, in step S4001, it is determined from the processing result in step S4000 whether or not the document conveyance can be started. If the document conveyance start permission state is not set, the document conveyance is not performed and the operation is ended to step S4015. To do.

On the other hand, in step S4001, if the document transport start permission state is set, the shutter 115 in FIG.
The weight 116 and the weight 116 is lowered.
The transport motor 128 is normally rotated (step S4002),
The conveying roller 119 and the separation roller 128 are driven to start the separation operation of the document bundle S. At this time, the registration roller 1
18 and the discharge roller 117 are not driven. Then, based on a signal from the registration sensor 112, it is judged whether or not the registration sensor 112 has detected the leading edge of the separated document (step S4003).
In order to remove the skew, the original is abutted against the registration roller 118 and the timer is started so that the motor is stopped (step S4004). When this timer operation ends (step S4005), the motor 128 is stopped (step S4006), and the separating operation ends.

Next, the rotation direction of the separation / conveyance motor 128 is reversed to disconnect the drive of the conveyance roller 119 and the separation roller 128, and the registration roller 118 and the paper discharge roller 11 are removed.
7 are driven to start the conveyance of the original document in a state of being abutted against the registration roller 118 (step S4007). The original is read while being conveyed on the fixed position of the optical system of the main body, and it is judged from the signal from the registration sensor 112 whether or not the rear end of the original is detected by the registration sensor 112 (step S4008). If it is determined that the detection is made, the timer is started so that the motor is stopped when the trailing edge of the document passes the reading position (step S).
4009). When the timer expires (step S401
0), the motor 128 is stopped (step S4011),
The reading operation ends.

Here, it is judged from the signal from the document detecting sensor 111 whether or not there is a next document (step S).
4012). If it is determined that there is the next manuscript, step S
Returning to 4002, when the next read original is subjected to the same steps as above up to step S4006, the operation of separating the next original is completed. During this time, since the registration roller 118 and the paper discharge roller 117 are not driven, the read document is held with the trailing edge at the reading position.

Next, in step S4007, when step S4011 is performed, the separation / conveyance motor 128 reversely rotates, and the registration roller 118 and the paper discharge roller 117 are driven to perform the next document reading operation. , The read document is discharged onto the discharge tray 121. In step S4012, when the document detection sensor 111 determines that there is no next document, it is determined that the read document is the last sheet of the document stack S, and therefore the process of separating the next document is not performed, and the process proceeds to step S4013. Advance, separation / conveyance motor 1
28 is reversed, and the discharge roller 117 is driven to start the discharge operation of the final sheet.

At the start of the operation, the document is nipped by the paper discharge roller 117 because of the structure, and therefore the paper discharge roller 11 is used.
Since the paper discharge sensor 113 disposed near 7 detects the original, the paper discharge sensor 113 detects the rear end of the original in step S4014. If the rear end is detected, the rear end of the original is the paper output roller. After the motor is driven for the amount passing through 117, the separation / conveyance motor 128 is stopped (step S401).
5).

(B) Next, the sequence of the document transport start pre-processing operation will be described with reference to the flowchart of FIG. 3; when the start key of the copying machine main body 200 is pressed and the document transport start signal is received, it is ejected. In order to be able to detect all document types on the paper tray 121, it is determined whether or not there is a document on the paper discharge tray 121 from the output signal of the sheet detection sensor 114 arranged in the center near the paper discharge port. (Step S3000). As a result of the determination, the discharge tray 121
If it is determined that there is no document on the upper side, the process jumps to step S3005, and the document conveyance permission state is set.

On the other hand, if it is determined in step S3000 that there is no document, the partition lever sensor 124 detects whether or not the partition lever 123 for distinguishing each document is set (step S3).
001), if the partition lever is not yet set, the partition lever 123 is rotated by a motor (not shown), and the partition lever 123 is set on the uppermost surface of the document stack S of the paper discharge tray 121 (step S3003).

As a result, since it becomes possible to distinguish the document bundle S, the process advances to step S3005 to set the document transport start permission state, and waits for the operation start. However, when the original is removed, the partition lever 123 set on the original returns to the initial position due to its own weight.

On the other hand, when it is detected in step S3001 that the partition lever 123 has already been set, if the operation is started as it is, it becomes impossible to distinguish the document bundle S. To ADF1
00, a warning is given on the display section 122 provided on the cover, and a warning on the display section of the main body of the copying machine (not shown) warns the user to remove the stack of the originals on the discharge tray 121 to start the original conveyance. Put in a prohibited state.

(C) Next, the paper discharge control operation will be described; as can be seen from the flow of the control of the ADF, the read document is held by the paper discharge roller 117 and waits for the end of separation of the next document. . After that, when conveyance is started in order to read the next original, the discharge roller 11 which is the same drive system
Since 7 is driven, the paper discharge operation is performed. The discharge speed at this time is the same as the reading speed of the next original. Therefore, according to the output of the document detection sensor 111,
When there is a document to be read next, the discharge speed is determined by the document processing conditions.

However, when the original detection sensor 111 determines that there is no next original after the reading of the original, the separating operation is not performed, and the operation of discharging the last sheet that has been read is performed. At this time, since the reading speed of the next original can be ignored, the discharge speed can be set freely. Therefore, in the case of the last sheet, in order to speed up the series of document processing, the separation / conveying roller (not shown) is driven at the maximum speed during reading to discharge the last sheet regardless of the operating conditions. It was done.

[0027]

As described above, according to the present invention,
By maximizing the discharge speed of the final sheet that is not affected by the conveyance speed of the next original, the processing time for a series of originals can be shortened.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an ADF according to an embodiment.

FIG. 2 is an enlarged view of the paper discharge tray portion of FIG.

FIG. 3 is a flowchart of a document transport start pretreatment operation.

FIG. 4 is a control operation flowchart of the ADF.

FIG. 5 is a block diagram of the ADF control unit circuit configuration.

[Explanation of symbols]

 100 Automatic Document Feeder (ADF) 111 Document Detection Sensor 113 Paper Ejection Sensor 114 Sheet Detection Sensor 117 Paper Ejection Roller 120 Document Placement Table 121 Paper Ejection Tray 122 Display Unit 123 Partition Lever 124 Partition Lever Sensor 128 Separation / Conveyance Motor 130 Partition Lever Motor 200 Image forming apparatus (copying machine) main body 202 Platen glass 500 Control device 501 CPU 502 ROM 503 RAM S Document stack

Claims (1)

[Claims] 1. An automatic document feeder for exposing a document while conveying the document, having a speed-switchable conveying means, a final paper detecting means, and a discharge driving means, and outputting the final paper by the output of the detecting means. If it is determined that the above-mentioned condition is satisfied, the discharge driving unit is operated at a maximum speed that the conveying unit can perform, and discharge control of the final sheet is performed.