JPH0532354A - Document feed device - Google Patents

Abstract

PURPOSE:To provide a document feed device having the capability of reducing a non-feed rate by restarting (retrying) separation and carriage operation, upon occurrence of non-feed. CONSTITUTION:An S2 sensor 32 makes judgement, regarding the existence or non-existence of a document, and detects the non-feed of the document by detecting the leading end of the document carried with a feed roller as a carriage means. A retry control section 53 causes a separation means and a carriage means to start again separation and carriage operation, when the non-feed of the document is detected by the S2 sensor 32. If the non-feed of the document is detected after the restart of said means, retry state continues. Also, retry by the means is repeated, upon detection of the non-feed. A maximum value for retry repetition, however, is predetermined at the frequency of (n).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder applied to, for example, a copying machine, a facsimile machine, an image scanner, etc., and more particularly to a document feeder for separating and transporting a plurality of documents one by one.

[0002]

2. Description of the Related Art Conventionally, in a document reading device such as an image scanner, a document feeding device so-called ADF (Auto Document Feeder) which conveys a plurality of documents one by one to a reading portion is often used. The document feeder includes a separating unit that separates one of a plurality of documents and a conveying unit that conveys the separated document, and separates the read document from other documents and conveys the document. .

[0003]

However, in such a conventional document feeder, a document cannot be transported, that is, a document cannot be transported due to abrasion of the separating / transporting member, diversification of the types of documents transported, or the like. The frequency of non-feed (non-feed) tends to increase. Conventionally, in order to reduce the non-feed occurrence rate, a mechanical mechanism is mainly changed, but it is difficult to achieve the non-feed occurrence rate of 0% under all conditions.

Therefore, an object of the present invention is to provide an original feeding apparatus capable of reducing the non-feed occurrence rate by restarting (retrying) the separating / conveying operation when non-feed occurs. It is another object of the present invention to provide a document feeder that increases the reliability of separation and conveyance by variably setting the separation conveyance speed at restart to a low speed.

When the above object is achieved, the document feeder restarts the separation / conveyance operation when non-feed occurs, but if a document which is very difficult to separate is set, a retry operation frequently occurs. . As a result, the non-feed occurrence rate decreases, but it takes more than double the time. Therefore, an object of the present invention is to provide a document feeding apparatus which can minimize the non-feed occurrence rate and can be separated and conveyed in a short time by automatically setting the highest speed for sure separation and conveyance. I am trying.

[0006]

The invention according to claim 1 is
In order to achieve the above object, in a document feeder including a separating unit that separates one of a plurality of documents and a conveying unit that conveys the separated document, the document is conveyed by the conveying unit. A document non-feeding detecting unit that determines the presence or absence of a document and detects a document non-feeding, and a restart control unit that restarts the separating and conveying operation by the separating unit and the conveying unit when the document non-feeding is detected. It is characterized by that.

In order to achieve the above object, the invention according to claim 2 is such that a speed table storing several kinds of separation / conveyance speeds by the separating means and the conveying means, and a separation / conveyance stored in the speed table. And a speed control unit for variably setting the separation / conveyance speed restarted after detecting the document non-feed according to the speed to a lower speed side.

Further, in order to achieve the above object, the invention according to claim 3 is such that, when the separation / conveyance succeeds at the separation / conveyance speed variably set at the time of restart, the separation / conveyance for the next time and thereafter is carried out by this separation / conveyance speed. If the separation / conveyance operation at the separation / conveyance speed succeeds a predetermined number of times in succession, the separation / conveyance speed is variably set to a higher speed side.

[0009]

According to the present invention having the above-mentioned structure, the document non-feeding is detected by determining the presence or absence of the document to be transported by the transporting means, and when the document non-feeding is detected, the separating means and the transporting means are provided. The separating and conveying operation by the means is restarted. Further, in the invention having the above-mentioned structure, several kinds of separation / conveyance speeds by the separating means and the conveying means are stored in the speed table, and the document non-feed is detected according to the separation / conveyance speed stored in the speed table. The separation / conveyance speed restarted thereafter is variably set to a lower speed side.

Further, in the invention according to claim 3 having the above-mentioned structure, when the separation / conveyance succeeds at the separation / conveyance speed which is variably set at the time of restart, the separation / conveyance is performed from the next time onward by this separation / conveyance speed, When the separating and conveying operation at the separating and conveying speed succeeds a predetermined number of times in succession, the separating and conveying speed is variably set to a higher speed side.

[0011]

EXAMPLES The present invention will be described below based on examples.
FIG. 1 is a block diagram showing an image reading apparatus to which a document feeding apparatus according to an embodiment of the invention described in any one of claims 1 to 3 is applied. 2 is a configuration diagram of the embodiment shown in FIG. 1. FIG. 2A is an external view thereof, FIG. 2B is a sectional view thereof, and FIG. 2C is a partially enlarged view of the section. .

First, the structure will be described. In FIG. 2A, a pressure plate 13 integrally formed with a document feeder (ADF) 12 is provided on an upper portion of a main body 11 of the image reading device.
The original document conveyed by the ADF 12 is discharged to the tray 14. In FIG. 2B, one or more originals 15 are set on the original table 16 and are fed to the separating means by the pickup roller 17. The separating means is composed of a feed roller 18 and a separating roller 19, and separates one of a plurality of originals. The driving force is applied only to the feed roller 18,
The lowermost (lower) original is separated one by one by the pressure contact load of the separation roller 19 which is pressed against. The conveying means for conveying the separated originals is the feed rollers 20 (a, b), 2
1, 22 (a, b) and 23 (a, b).

The document conveyed by the feed roller 20 and the like is illuminated by the light source 24 and the like at the reading position A, and the reflected light from the reflecting mirrors 25a, 25b, 25c and the like is introduced into the reading unit 27 through the lens 26. To be done. The reading unit 27 converts the reflected light into a CCD (Charge Coupled).
Device) to read. In addition, in FIG.
Reference numeral 8 denotes an original glass, and the pressure plate 13 is lifted to set the original document surface when reading the original document, for example.
In this case, the optical system side such as the light source 24 and the reflection mirror 25 is moved to read the original surface.

In FIG. 2C, the S1 sensor 31 is a document set sensor, and detects whether or not a document is set on the document table 16. The S2 sensor 32 is a document leading edge detection sensor and detects the leading edge of the document conveyed by the feed roller 20. The S3 sensor 33 is a paper discharge sensor, and detects the trailing edge of the document discharged by the feed roller (paper discharge roller) 23.

In FIG. 1, the CCD 41 is the reading unit 2
7 is a photoelectric conversion device, which converts reflected light from the document surface into an electric signal and outputs an image signal. This image signal is amplified to a predetermined level by the amplifier 42. Next, the image correction circuit 44 corrects the shading density unevenness of the light source 24. The binarization circuit 45 binarizes the corrected image signal into black and white pixel data.
The binarized pixel data is stored in the line buffer 46 and then transferred to, for example, an I / F (interface) for sending to a printer or a communication line.

The pickup motor 47 is a motor for driving the pickup roller 17, and the feed motor 48 is a motor for driving the feed roller 20 and the like. The pickup motor 47 and the feed motor 48 are given drive signals by drive circuits 49 and 50, respectively. The motor speed control unit 51 outputs a control signal to the drive circuits 49 and 50 to give a speed command. C
The PU (Central Processing Unit) 52 is, for example, an RO.
The entire system of the image reading apparatus is controlled according to a program stored in M (Read Only Memory) or the like.

Here, the S2 sensor 32 serves as a document non-feeding detecting means for detecting the document non-feed by detecting the leading edge of the document transported by the feed roller 20 which is a transporting means and detecting the document non-feeding. Function. When the S2 sensor 32 detects that the document has not been fed, the restart control unit 53 causes the separating means (the feed roller 18 and the separating roller 19) and the conveying means (the feed roller 2).
0) to restart the separation / conveyance operation. It should be noted that, if the document non-feed is detected after the restart, the restart is continuously performed, and when the document non-feed is detected, the document is repeatedly restarted. However, the maximum value of the number of times the restart is repeated is set to a predetermined number n in advance.

In the speed table 54, several kinds of separation / conveyance speeds by the separating means and the conveying means, that is, speeds of the pickup motor 47 and the feed motor 48 are stored in advance. The motor speed control unit 51 variably sets the separation conveyance speed (motor speed) restarted after the document non-feed detection to a lower speed side in accordance with the separation conveyance speed (motor speed) stored in the speed table 54. To do.

If the separation / conveyance speed variably set at the time of restart succeeds in the separation / conveyance, the motor speed control unit 51 carries out the separation / conveyance at the next time and thereafter. Then, when the separating and conveying operation at the separating and conveying speed succeeds a predetermined number of times in succession, the separating and conveying speed is variably set to a higher speed side. Next, the operation will be described.

First, the document non-feeding detection process at the time of document separation will be described with reference to the flowchart shown in FIG.
The CPU 52 checks with the S1 sensor 31 whether or not the document 15 is set on the document table 16 (step S1). If there is no document, a document NOT-SET error is returned (step S2) and the user is prompted to set the document appropriately. On the other hand, if there is, the pickup roller 17, the feed roller 18 (separating means), the feed roller 20 (conveying means), and the feed rollers 21 to 23 are simultaneously rotated at the same speed (step S3). The pickup roller 17 and the feed rollers 18, 20 to 23 can be operated separately. In this case, the feed roller 1
8 and 20 to 23 are accompanied.

When the pickup roller 17 makes one rotation and the pickup operation is completed (step S4), the original 1
Several sheets from the bottom of 5 are carried to the separation roller 19. Separation roller 1
The second and subsequent originals are stopped by 9, and only the lowermost first original is separated by the feed roller 18. The separated original is conveyed by the feed roller 20,
The S2 sensor 32 is turned on.

The CPU 52 can check the S2 sensor 32 (step S5) and know the position of the leading edge of the document when it is turned on. The reading position A is a position where the S2 sensor 32 is conveyed by several mm to several tens of mm from the time when it is turned on.
(Step S6), after the reading operation is performed at this position (step S7), the document is fed by the feed roller 22,
It is conveyed to 23 and discharged (step S8).

Regarding ejection, it is checked whether or not the S3 sensor 33 is turned on for a certain period of time while the document is passing (steps S9 and S10). It is determined that the discharge is completed (step S11), and the process ends. If it is not turned off within a fixed time, it is determined that a jam (paper jam) error has occurred (step S12).

Now, how to detect non-feed will be described. Originally, documents that have been separated and conveyed must always have S
2 Turn on the sensor. However, if the original does not reach the feed roller 18 of the separating section, the original cannot be separated no matter how many rotations the feed roller 18 makes. Therefore, when the S2 sensor 32 is not turned on even after a certain period of time has passed since the separation operation was started (step S13), it is determined that non-feed has occurred (step S14).

The above is the document non-feed detection process. The operation of the embodiment according to the present invention to which this process is applied will be described with reference to the flow chart shown in FIG. First, the CPU 52 checks with the S1 sensor 31 whether or not the document 15 is set on the document table 16 (step T1). If there is no document, a document NOT-SET error is returned (step T2) and the user is prompted to set the document appropriately.

On the other hand, if there is, the restart control section 53 resets, ie, sets 0, the built-in separation trie counter (not shown) (step T3) and then sets +1 (step T4). Next, the pickup roller 17, the feed roller 18 (separating means), the feed roller 20 (conveying means), and the feed rollers 21 to 23.
Are simultaneously rotated at the same speed (step T5).

When the pickup roller 17 makes one rotation to complete the pickup operation (step T6), the original 1
Several sheets from the bottom of 5 are carried to the separation roller 19. Separation roller 1
The second and subsequent originals are stopped by 9, and only the lowermost first original is separated by the feed roller 18. The separated original is conveyed by the feed roller 20,
The S2 sensor 32 is turned on.

The CPU 52 can check the S2 sensor 32 (step T7) and know the leading edge position of the document when it is turned on. The reading position A is a position where the S2 sensor 32 is conveyed by several mm to several tens of mm from the time when it is turned on.
(Step T8), after the reading operation is performed at this position (step T9), the document is fed by the feed roller 22,
It is conveyed to 23 and discharged (step T10).

Regarding the ejection, it is checked whether or not the S3 sensor 33 is turned on for a certain period of time while the document is passing (steps T11 and T12). It is determined that the discharge is completed (step T13), and the process ends. If it does not turn off within a fixed time, it is determined that a jam (paper jam) error has occurred (step T14).

On the other hand, if it is determined in step T7 that the S2 sensor 32 has not been turned on for a certain period of time after the separation operation is started (step T15), the value of the separation trie counter in the restart control section 53 is determined. Is greater than a predetermined value n (step T
16) If the counter value is n or less, the process returns to step T4, the value of the separation trie counter is updated by +1 set, and the separation conveyance operation is restarted. On the other hand, step T16
If the counter value exceeds n by the above judgment, it is judged that separation and conveyance cannot be performed even after restarting n times, and a non-feed error is notified to the outside of the apparatus (step T17).

As shown in the above processing, in the present embodiment, the value of the separation trie counter is first set to "1" at the start of separation. After that, the count value is incremented by +1 each time the document separating / conveying operation is restarted. That is, while checking the value of the separation trie counter, if it is n or less, the separation conveyance operation is restarted. The counter value is n
If it becomes larger, an error will occur because it cannot be separated.

As described above, in this embodiment, since the separation / conveyance operation is restarted when non-feed occurs, even if the separation / conveyance performance is deteriorated due to the abrasion of the separation member or the type of the original, the separation / conveyance can be performed. The probability of success is improved, the non-feed occurrence rate can be reduced, and the separation performance can be significantly improved. Next, the operation of the embodiment according to the second aspect of the invention will be described with reference to the flow chart shown in FIG.

First, the CPU 52 places the original 1 on the original table 16.
The S1 sensor 31 checks whether or not 5 is set (step P1). If there is no original, the original
A NOT-SET error is returned (step P2), prompting the user to set an appropriate document. On the other hand, if there is, the restart control unit 5
3, the normal separation / conveyance speed is selected from the speed table 54 (step P3), and the built-in separation trie counter (not shown) is reset, that is, set to 0 (step P4), and then set to +1 (step P5). ).

Then, the pickup roller 17, the feed roller 18 (separating means), the feed roller 20 (conveying means), and the feed rollers 21 to 23 are simultaneously rotated at the same speed (step P6). When the pickup roller 17 makes one rotation to complete the pickup operation (step P7), several sheets from the bottom of the document 15 are conveyed to the separation roller 19. The separation roller 19 stops the second and subsequent originals, and the feed roller 18 separates only the bottom first original. The separated originals are fed by the feed roller 2
0 is conveyed and the S2 sensor 32 is turned on.

The CPU 52 can check the S2 sensor 32 (step P8) and know the leading edge position of the document when it is turned on. The reading position A is a position where the S2 sensor 32 is conveyed by several mm to several tens of mm from the time when it is turned on.
(Step P9), and after the reading operation is performed at this position (Step P10), the document is fed by the feed roller 2
The sheet is conveyed to 2, 23 and discharged (step P11).

Regarding ejection, it is checked whether or not the S3 sensor 33 is turned on for a certain period of time while the document is passing (steps P12 and P13). It is determined that the discharge is completed (step P14), and the process ends. If it does not turn off within the fixed time, it is determined that a jam (paper jam) error has occurred (step P15).

On the other hand, if it is determined in step P8 that the S2 sensor 32 is not turned on even after a certain period of time has elapsed since the separation operation was started (step P16), the value of the separation trie counter in the restart control section 53 is determined. Is greater than a predetermined value n (step P
17), if the counter value is n or less, the speed table 5
Select a lower separation conveyance speed from 4 (Step P1
8) Return to step P5, the value of the separation trie counter is updated by +1 and the separation conveyance operation is restarted.
On the other hand, if the counter value exceeds n in the determination in step P17, it is determined that the separation / conveyance could not be performed even after restarting n times, and a non-feed error is notified to the outside of the device (step P19).

When the restart control unit 53 restarts in this way, the motor speed control unit 51 drives in accordance with several to several tens of separation conveyance speeds (motor speeds) selected from the speed table 54. The speed command is output to the circuits 49 and 50. The pickup motor 47 and the feed motor 48 are driven to rotate at low speed according to this speed command, and are separated and conveyed at a low speed. As the speed decreases, the reliability of separation and conveyance improves, so that success of separation and conveyance can be expected each time the restart is repeated.

In the present embodiment, the slowest speed in the speed table 54 is controlled by the restart control unit 53 so that any document can be separated without fail when non-feed occurs during separation at normal speed. (Ie Speed
It is desirable to select 10) and restart at this slowest speed. As described above, in the present embodiment, the motor speed is reduced at the time of the second try when the non-feed occurs, that is, at the time of restart, so that the separation performance can be further improved and the non-feed occurrence rate can be further reduced. Play.

Next, the operation of the third embodiment of the invention will be described with reference to the flow chart shown in FIG. First, the CPU 52 checks with the S1 sensor 31 whether or not the document 15 is set on the document table 16 (step R1). If there is no original, the original NOT-SET
An error is returned (step R2) and the user is prompted to set an appropriate document.

On the other hand, if there is, the restart control unit 53 resets or sets 0 to the built-in success counter (not shown) (step R3), and the speed table 5
A normal separation conveyance speed such as Speedk is selected from 4 (step R4), and a built-in separation trie counter (not shown) is reset, that is, set to 0 (step R5), and then set to +1 (step R6).

Then, the pickup roller 17, the feed roller 18 (separating means), the feed roller 20 (conveying means), and the feed rollers 21 to 23 are simultaneously rotated at the same speed (step R7). When the pick-up roller 17 makes one rotation to complete the pick-up operation (step R8), several sheets from the bottom of the document 15 are carried to the separation roller 19. The separation roller 19 stops the second and subsequent originals, and the feed roller 18 separates only the bottom first original. The separated originals are fed by the feed roller 2
0 is conveyed and the S2 sensor 32 is turned on.

The CPU 52 can check the S2 sensor 32 (step R9) and know the leading edge position of the document when it is turned on. Here, the S2 sensor 32 is ON
Then, the value k of the success counter is incremented by +1 (step R10), and the reading position A is conveyed by several mm to several tens of mm from the time when the S2 sensor 32 is turned on.
Then, the reading operation is performed (step R11).
12). After that, the document is conveyed to the feed rollers 22 and 23 and discharged (step R13).

Regarding the ejection, it is checked whether or not the S3 sensor 33 is turned on for a certain period of time while the document is passing (steps R14 and R15). It is determined that the discharge is completed (step R16). In addition, OFF within a fixed time
If not, it is determined that a jam (paper jam) error has occurred (step R17).

After discharging, the S1 sensor 31 is checked (step R18), and if the S1 sensor 31 is OFF, it is determined that there is no next original document, and the process ends. If the S1 sensor 31 is ON, it is determined whether or not the value k of the success counter is larger than "10" (step R).
19). That is, it is determined whether or not the separating and conveying operation has succeeded 10 times or more continuously. Here, if the count value k is "10" or less, the process returns to step R4, and the next original is separated and conveyed at the current separation and conveyance speed set at the time of restart or the first start. On the other hand, when it is determined in step R19 that the separating and conveying operation succeeds ten times or more in succession, the motor speed control unit 51 sets a speed faster than the current separating and conveying speed, that is, Speed (k-1), to the speed table 54. After selecting from (step R20) and resetting the k value of the success counter (step R21), the process returns to step R5, and the next document is separated and conveyed at a higher separation and conveyance speed Speed (k-1).

On the other hand, if it is determined in step R9 that the S2 sensor 32 has not been turned on for a certain time after the separation operation is started (step R22), the value of the separation trie counter in the restart control section 53 is determined. Is greater than a predetermined value n (step R
23), if the counter value is n or less, the speed table 5
A slower separation conveyance speed, namely Speed (k + 1) is selected from 4 (step R25), the process returns to step R6, the value of the separation trie counter is updated by +1 set, and the separation conveyance operation is restarted. On the other hand, if the counter value exceeds n in the judgment of step R23, it is judged that the sheet cannot be separated and conveyed even after restarting n times, and a non-feed error is notified to the outside of the apparatus (step R24).

In this embodiment, several types of separation / conveyance speeds, for example, Speed 1 to 10 are set in the speed table 54 of FIG.
Define to. Speed1 is super high speed mode, Speed5 is normal speed mode, Speed10 is complete separation speed mode. Therefore, the larger the value, the slower the speed. In this embodiment, a success counter that counts up when the first separation trial is successful is provided. If it fails, the success counter is reset and 2
At the time of the first try, the sheet is separated and conveyed at a speed one step slower. Also, the first try of the next manuscript will be made at the same speed as the second try of the previous page that failed.

Further, when the success counter reaches 10, for example, 10 times in succession, the speed is increased by one step for the next original. By performing the above control,
Since the document is separated and conveyed at the fastest and optimal speed possible without being affected by the condition of the document 15, the wear of the separation roller 19, and other environmental conditions, the rate of success in the first try is increased, and the speed and reliability are improved. Both can be achieved.

That is, in the present embodiment, it is possible to automatically set the speed as high as possible and at the speed at which the separation can be surely performed, the non-feed generation rate can be reduced, and the optimum separation and conveyance can be performed in a short time. The speed can be set.

[0050]

As described above, according to the document feeding apparatus of the first aspect of the invention, the document feeding failure is detected by determining the presence or absence of the document transported by the transporting means, and the document feeding failure is detected. If a separation is detected, the separation and conveyance operations by the separation means and the conveyance means are restarted, so that the probability of successful separation and conveyance is improved even when the separation and conveyance performance is deteriorated due to wear of the separation member or the type of document. However, the non-feed generation rate can be reduced, and the separation performance can be significantly improved.

According to the document feeder of the second aspect of the invention, several kinds of separating / conveying speeds by the separating means and the conveying means are stored in the speed table, and the separating / conveying speeds stored in the speed table are stored. According to the above, since the separation / conveyance speed restarted after the document non-feed is detected is variably set to the lower speed side, the reliability of separation and conveyance at the time of restart can be increased, and the separation performance can be further improved. It is even more effective in reducing the non-feed occurrence rate.

According to the document feeder of the third aspect of the present invention, when the separation / conveyance succeeds at the separation / conveyance speed that is variably set at the time of restart, the separation / conveyance for the next time and thereafter is performed by this separation / conveyance speed. If the separating and conveying operation at this separating and conveying speed succeeds for a predetermined number of times in succession, the separating and conveying speed is variably set to a higher speed side, so that the speed is set as high as possible and the speed for sure separation is set automatically. Therefore, the non-feed occurrence rate can be reduced, and the optimum speed for separation and conveyance can be set in a short time.

[Brief description of drawings]

FIG. 1 is a block diagram showing an image reading device to which a document feeding device according to an embodiment of the invention described in any one of claims 1 to 3 is applied.

FIG. 2 is a configuration diagram of the embodiment shown in FIG. 1, and FIG.
Is an external view thereof, FIG. 2B is a sectional view thereof, and FIG. 1C is a partially enlarged view of the section.

FIG. 3 is a flowchart showing a document non-feed detection process at the time of document separation.

FIG. 4 is a flowchart showing an operation of the embodiment according to the invention described in claim 1.

FIG. 5 is a flow chart showing an operation of an embodiment according to the invention described in claim 2.

FIG. 6 is a flow chart showing an operation of an embodiment according to the invention described in claim 3;

[Explanation of symbols]

18 Feed roller (separation means) 19 Separation roller (separation means) 20 Feed roller (conveying means) 32 S2 sensor (document non-feeding detection means) 51 Motor speed controller (speed controller) 53 Restart controller 54 speed table

Claims (3)

[Claims] 1. A document feeding apparatus comprising: a separating unit that separates one of a plurality of documents and a conveying unit that conveys the separated document, wherein the document is conveyed by the conveying unit. And a restart control unit for restarting the separating and conveying operation by the separating unit and the conveying unit when the document non-feed is detected. Characteristic document feeder. 2. A speed table storing several kinds of separation / conveyance speeds by the separating means and the conveying means, and a separation / conveyance speed restarted after the document non-feed detection according to the separation / conveyance speed stored in the speed table. The document feeder according to claim 1, further comprising: a speed control unit that variably sets to a lower speed side. 3. When the separation / conveyance succeeds at the separation / conveyance speed which is variably set at the time of restart, the separation / conveyance is performed from the next time onward at the separation / conveyance speed, and the separation / conveyance operation at the separation / conveyance speed continues for a predetermined number of times. If successful,
3. The document feeder according to claim 2, wherein the separation / conveyance speed is variably set to a higher speed side.