JPH10173864A - Image reading device and method, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a normal scanning operation against occurrence of the torque deficiency of a scanner motor by securing the proper driving force for the following scanning operation if a scanning means has a moved variable that is different from the original size. SOLUTION: If the read scanning abnormality that is caused by the torque deficiency of a scanner motor, etc., is decided, a main CPU 91 sets the current value of a scanner motor driver 104 at 1.5A, for example, by increasing it by 0.5A against the scanner motor. If the scanner motor has an abnormal operation due to its torque deficiency, etc., and the read scanning abnormality is decided under such conditions, the CPU 91 decides the second read scanning abnormality and sets again the current value of the driver 104 at 2.0A by increasing it by 0.5A against the scanner motor. Thus, the torque of the scanner motor can be increased at the next scanning operation even when the scanner motor stops its operation due to its torque deficiency. As a result, a smooth scanning operation is ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image reading apparatus such as a scanner used in an electronic copying machine or the like, an image forming apparatus using the image reading apparatus, and an image reading method.

[0002]

2. Description of the Related Art Conventionally, in an image reading apparatus such as a scanner used in an electronic copying machine or the like, for controlling a scanner motor, for example, in the case of a stepping motor, the motor is controlled by a drive pulse from a CPU as a control unit. Is going. In the case of a DC motor, control is performed by comparing a control frequency from the CPU with an output frequency from an encoder provided in the motor.

In such an image reading apparatus, a scanner motor drives a carriage (equipped with a mirror and a lamp) for exposing and reading an original. For example, in the case of a stepping motor, when the motor torque is insufficient,
The carriage stops halfway. However, the CPU controlling the motor does not know the situation at this time. For this reason, the carriage stopped during the scanning operation collides with the housing beyond the scanning operation start position during the back scan.

[0004] As a result, the left and right balance adjustment of the carriage is deviated, and the mirror and lamp of the carriage are damaged. In the case of a DC motor, if the torque of the motor is insufficient, the carriage stops, and the power must be once turned off to restart the carriage. Therefore, there is a drawback that a normal scanning operation cannot be performed when the torque of the scanner motor is insufficient.

[0005]

SUMMARY OF THE INVENTION The present invention eliminates the disadvantage that a normal scanning operation cannot be performed when the torque of the scanner motor is insufficient, as described above. It is an object of the present invention to provide an image reading apparatus, an image forming apparatus, and an image reading method that can perform a normal scanning operation when a motor torque shortage occurs.

[0006]

An image reading apparatus according to the present invention comprises a document table on which a document is placed, a scanning means for reading and scanning the document placed on the document table, and the scanning means being mounted on the document table. A moving means for relatively moving the moving means with respect to the moving means; a driving means for driving the moving means by a first driving force so as to move the scanning means by an amount corresponding to the document size; Detecting means for detecting that the scanning means has a different moving amount from that corresponding to the document size when the means supplies the first driving force by the amount corresponding to the document size, based on the detection of the detecting means And a changing means for changing the driving force so as to drive with the second driving force so as to optimize the driving force supplied to the moving means by the driving means in the subsequent scanning operation.

An image reading apparatus according to the present invention includes a document table on which a document is placed, scanning means for reading and scanning the document placed on the document table, and moving the scanning means relative to the document table. Moving means for driving, a driving means for driving the moving means with a predetermined driving force so as to move the scanning means by an amount corresponding to the document size, the driving means for the moving means,
When the scanning means supplies a predetermined driving force by the amount corresponding to the document size, a detecting means for detecting that the scanning means has a moving amount different from the amount corresponding to the document size. And a notifying means for notifying the user of an abnormal state.

An image reading apparatus according to the present invention includes a document table on which a document is placed, scanning means for reading and scanning the document placed on the document table, and moving the scanning means relative to the document table. Moving means for moving, a first detecting means for detecting the size of a document placed on the document table, and a scanning means for moving the moving means with a first driving force in accordance with a detection result by the first detecting means. A driving means for driving so as to move the document by an amount corresponding to the document size. When the driving means supplies a first driving force to the moving means by a distance corresponding to the document size, the scanning means A second detecting means for detecting that the document has not been moved by an amount corresponding to the document size; based on the detection of the second detecting means, the driving means supplies a driving force to be supplied to the moving means in a subsequent scanning operation. Increase the amount And a control means for limiting the number of continuous scans by the scanning means when the driving force supplied by the driving means is increased by the changing means. I have.

An image reading apparatus according to the present invention includes a document table on which a document is placed, reading means for reading an image from the document placed on the document table, and a moving means for moving the reading means along the document table. Means, a plurality of detection means provided in the reading means, for detecting the presence or absence of a document placed on the platen,
By moving these detecting means by the moving means, a first judging means for judging the size of the original placed on the original platen based on a detection signal from the detecting means, the first judging means Control means for controlling the movement of the moving means by the size of the document in accordance with the determination result by the means, when the movement of the moving means is controlled by this control means,
An output unit that outputs a reading output from the reading unit as a reading result; and when the moving unit is controlled to move by the size of the document by the control unit, the presence of the document is detected by the detecting unit. A second judging means for judging an abnormality of the moving means, and a changing means for changing the driving force of the moving means in a stepwise manner when the second judging means judges the abnormality of the moving means. I have.

An image reading apparatus according to the present invention includes a document table on which a document is placed, reading means for reading an image from the document placed on the document table, and a moving means for moving the reading means along the document table. Means, a plurality of detection means provided in the reading means, for detecting the presence or absence of a document placed on the platen,
By moving these detecting means by the moving means, a first judging means for judging the size of the original placed on the original platen based on a detection signal from the detecting means, the first judging means Control means for controlling the movement of the moving means by the size of the document in accordance with the determination result by the means, when the movement of the moving means is controlled by this control means,
An output unit that outputs a reading output from the reading unit as a reading result; and when the moving unit is controlled to move by the size of the document by the control unit, the presence of the document is detected by the detecting unit. Second determining means for determining an abnormality of the moving means; changing means for changing the driving force of the moving means in a stepwise manner when the second determining means determines that the moving means is abnormal; When the driving force of the moving means changed by the driving means reaches the limit value, a notification means for notifying the change limit by the changing means is provided.

An image reading apparatus according to the present invention has a document table on which a document is placed, reading means for reading an image from the document placed on the document table, and a moving means for moving the reading means along the document table. Means, a plurality of detection means provided in the reading means, for detecting the presence or absence of a document placed on the platen,
By moving these detecting means by the moving means, a first judging means for judging the size of the original placed on the original platen based on a detection signal from the detecting means, the first judging means Control means for controlling the movement of the moving means by the size of the document in accordance with the determination result by the means, when the movement of the moving means is controlled by this control means,
An output unit that outputs a reading output from the reading unit as a reading result; and when the moving unit is controlled to move by the size of the document by the control unit, the presence of the document is detected by the detecting unit. A second determining means for determining an abnormality of the moving means, and a notifying means for notifying the external device of the abnormality of the moving means when the second determining means determines the abnormality of the moving means. .

According to the image forming apparatus of the present invention, there is provided a document table on which a document is placed, scanning means for reading and scanning the document placed on the document table, and moving the scanning means relative to the document table. Moving means for driving, the driving means for driving the moving means by a first driving force to move the scanning means by an amount corresponding to the document size, and the driving means for the moving means,
The first movement of the scanning means by the amount corresponding to the document size
When the driving force is supplied, the scanning unit detects that the moving amount is different from the moving amount corresponding to the document size.Based on the detection by the detecting unit, in the subsequent scanning operation,
Changing means for changing the driving force so as to be driven by the second driving force so as to optimize the driving force supplied to the moving means by the driving means, and the moving means driven by the driving means being the scanning means And an image forming means for forming an image of the document obtained by moving the image on the image forming medium.

An image forming apparatus according to the present invention includes a document table on which a document is placed, scanning means for reading and scanning the document placed on the document table, and moving the scanning means relative to the document table. Moving means for driving, the driving means for driving the moving means by a first driving force to move the scanning means by an amount corresponding to the document size, and the driving means for the moving means,
The first movement of the scanning means by the amount corresponding to the document size
Detecting means for detecting that the scanning means has a movement amount different from the document size equivalent when supplying the driving force, a notifying means for notifying an abnormal state based on the detection of the detecting means, The moving means driven by the driving means comprises an image forming means for forming an image of a document obtained by moving the scanning means on an image forming medium.

According to the image reading method of the present invention, there is provided a document table on which a document is placed, scanning means for reading and scanning the document placed on the document table, and moving the scanning means relative to the document table. A moving means for moving the moving means by a first driving force so that the scanning means moves the document by an amount corresponding to the document size. Supplies the first driving force by the amount corresponding to the document size, the scanning means detects that the moving amount is different from the amount corresponding to the document size. ,
In order to optimize the driving force supplied to the moving means by the driving means, the driving force is changed so as to be driven by the second driving force.

According to the image reading method of the present invention, there is provided a document table on which a document is placed, scanning means for reading and scanning an image from the document placed on the document table, and a scanning means for moving the scanning means relative to the document table. Moving means for moving the moving means,
Driving means for driving the scanning means to move the document size equivalent amount by the driving force, wherein the driving means moves with respect to the moving means by only the first time the scanning means moves by the document size equivalent amount. When the driving force is supplied, the scanning means detects that the moving amount is different from the amount corresponding to the document size, and notifies an abnormal state based on the detection.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a schematic configuration of a digital copying machine as an example of an image forming apparatus having a scanner section as an image reading apparatus of the present invention.

As shown in FIG. 1, the digital copying machine includes an apparatus main body 10, in which a scanner section 4 as image reading means and a printer section 6 functioning as image forming means are provided. ing.

On the upper surface of the apparatus main body 10, there is provided an original placing table (original table) 12 made of transparent glass on which an object to be read, that is, the original D is placed. The device body 1
An automatic document feeder 7 (hereinafter, referred to as an ADF) for automatically feeding the document D onto the document table 12 is disposed on the upper surface of the document feeder 12. The ADF 7 is provided so as to be openable and closable with respect to the document table 12, and also functions as a document holder for bringing the document D placed on the document table 12 into close contact with the document table 12.

The ADF 7 includes a document tray 8 on which a document D is set, an empty sensor 9 for detecting the presence or absence of the document D,
A pickup roller 14 for taking out the originals D one by one from the original tray 8, a paper feed roller 15 for transporting the originals D taken out, a pair of aligning rollers 16 for aligning the leading end of the original D, and almost the entire original placing table 12 A transport belt 18 is provided so as to be covered. This transport belt 18
Although the entire surface is colored yellow, yellow tape is applied only to the portions facing the detection areas of the reflective interrupters 35 and 36 described later. The plurality of originals set upward on the original tray 8 are taken out in order from the bottom page, that is, the last page, are aligned by the aligning roller pair 16, and are placed on the original by the transport belt 18. The sheet is transported to a predetermined position on the table 12.

In the ADF 7, a reversing roller 20, a non-reversing sensor 21, a flapper 22, and a paper discharging roller 23 are disposed at an end opposite to the aligning roller pair 16 with the transport belt 18 interposed therebetween. The document D whose image information has been read by the scanner unit 4 described below is sent out from the document table 12 by the conveyance belt 18 and
The ADF 7 is discharged onto a document discharge unit 24 on the upper surface of the ADF 7 via a non-reversing sensor 21, a flapper 22, and a discharge roller 23. When reading the back surface of the original D, the original D transported by the transport belt 18 is inverted by the reversing roller 20 by switching the flapper 22, and is again moved to a predetermined position on the original placing table 12 by the transport belt 18. Sent.

The scanner unit 4 provided in the apparatus main body 10
Is an exposure lamp 2 serving as a light source for illuminating a document D placed on a document table 12 as shown in FIGS.
5, and a first mirror 26 for deflecting the reflected light from the document D in a predetermined direction. These exposure lamps 25 and the first mirror 26 are connected to a first mirror 26 disposed below the document table 12. It is attached to one carriage 27.

On the first carriage 27, there are provided two reflection type photo interrupters 35 and 36 as detecting means for detecting the size of the original D placed on the original placing table 12 and the presence or absence of the original D. Have been. The reflection type photo interrupter 35 is provided on the rear side of the first carriage 27, and the reflection type photo interrupter 36 is provided on the front side of the first carriage 27. Each of the reflection type photo interrupters 35 and 36 is constituted by an infrared light emitting diode LED as a light emitting element and a photo interrupter PD as a light receiving element.

By setting a document D and pressing a copy key 82 described later, the first carriage 27 of the scanner unit 4 prescans the document D without turning on the exposure lamp 25, thereby setting the original D. The size can be detected by the reflection type photo interrupters 35 and 36.

The first carriage 27 is mounted on the original table 12.
And a scanner motor (drive motor) 37 via a not-shown toothed belt or the like.
The document is reciprocated below the document table 12. The scanner motor 37 is configured by a stepping motor.

The torque (driving force) of the scanner motor 37
Sets the set current (motor phase current) of the scanner motor 37 to 1.0 A under the control of the main CPU 91 described later.
It can be changed in three stages of 1.5A and 2.0A.

However, as shown in FIG. 4, when the set current of the scanner motor 37 is 1.0 A, the temperature rise of the scan motor driver 104 is within the safe range regardless of the number of continuous copies. When the set current of the scanner motor 37 is 1.5 A, if the number of continuous copies exceeds 20, the temperature rise of the scanner motor driver 104 exceeds the temperature rise margin range outside the safe range and reaches the temperature rise limit value. If the set current of the scanner motor 37 is 2.0 A, if the number of continuous copies exceeds 10, the temperature rise of the scanner motor driver 104 exceeds the temperature rise margin outside the safe range and the temperature rises. Limits may be reached. Therefore, the scanner motor 37
Is 1.5 A, the number of continuous copies is 20
And the set current of the scanner motor 37 is 2.
In the case of 0A, the number of continuous copies is limited to ten. The temperature rise margin is provided in consideration of variations in devices.

A second carriage 28 that can move in parallel with the document placing table 12 is provided below the document placing table 12. On the second carriage 28, second and third mirrors 30, 31 for sequentially deflecting the reflected light from the document D deflected by the first mirror 26 are attached at right angles to each other. The second carriage 28 is driven by the first carriage 27 by transmitting the rotational force from the scanner motor 37 by a toothed belt or the like that drives the first carriage 27, and is driven by the first carriage 27. On the other hand, it is moved in parallel along the document table 12 at a half speed.

An image forming lens 32 for converging the reflected light from the third mirror 31 on the second carriage 28 and a reflected light condensed by the image forming lens 32 are provided below the document table 12. A CCD sensor 34 that receives light and performs photoelectric conversion is provided. The imaging lens 32 includes the third mirror 3
It is movably disposed via a drive mechanism in a plane including the optical axis of the light deflected by 1, and moves itself to form an image of reflected light at a desired magnification. Then, the CCD sensor 34
Converts the incident reflected light into a photoelectric signal and outputs an electric signal corresponding to the read original D.

On the other hand, the printer section 6 includes a laser exposure device 40 which functions as a latent image forming means. The laser exposure device 40 includes a semiconductor laser 41 as a light source, a polygon mirror 38 as a scanning member that continuously deflects laser light emitted from the semiconductor laser 41, and a polygon mirror 38 that rotates at a predetermined rotation speed described later. A polygon motor 39 as a scanning motor to be driven, and a polygon mirror 3
8 to deflect the laser beam from
And an optical system 42 for guiding to the The laser exposure apparatus 40 having such a configuration is fixedly supported by a support frame (not shown) of the apparatus main body 10.

The semiconductor laser 41 is turned on and off in accordance with image information of the document D read by the scanner unit 4 and the laser beam is directed to a photosensitive drum 44 via a polygon mirror 38 and an optical system 42. The electrostatic latent image is formed on the peripheral surface of the photosensitive drum 44 by scanning the peripheral surface of the photosensitive drum 44.

The printer unit 6 has a rotatable photosensitive drum 44 as an image carrier disposed substantially at the center of the apparatus main body 10. And a desired electrostatic latent image is formed. On the peripheral surface of the photosensitive drum 44, a charging charger 45 for charging the drum peripheral surface to a predetermined charge,
A developing device 46 for supplying toner as a developer to the electrostatic latent image formed on the peripheral surface of the photosensitive drum 44 to develop the electrostatic latent image at a desired image density, a transfer material fed from a paper cassette described later, A transfer charger 48 for integrally transferring a toner image formed on the photosensitive drum 44 to the paper P, and a separation charger 47 for separating the copy sheet P from the photosensitive drum 44; A peeling claw 49 for peeling off the copy paper P, a cleaning device 50 for cleaning the toner remaining on the peripheral surface of the photosensitive drum 44, and a static eliminator 51 for removing static on the peripheral surface of the photosensitive drum 44 are arranged in this order.

An upper cassette 52, a middle cassette 53, and a lower cassette 54, which can be pulled out from the apparatus main body, are arranged in a stacked state at a lower portion in the apparatus main body 10, and copy papers having different sizes are provided in each cassette. It is loaded. A large-capacity feeder 55 is provided beside these cassettes, and a large-capacity feeder 55 is provided on the large-capacity feeder 55. The large-capacity feeder 55 includes copy paper P of a frequently used size, for example, A4 size copy paper. P is about 30
00 sheets are stored. Above the large-capacity feeder 55, a paper feed cassette 57 also serving as a manual feed tray 56 is detachably mounted.

In the apparatus main body 10, a transport path 5 extending from each cassette and the large-capacity feeder 55 through a transfer portion located between the photosensitive drum 44 and the transfer charger 48 is provided.
8 are formed, and a fixing lamp 60a is provided at the end of the conveyance path 58.
Is provided. Fixing device 60
A discharge port 61 is formed in the side wall of the apparatus main body 10 facing the device, and a finisher 150 is attached to the discharge port 61.

In the vicinity of the upper cassette 52, the middle cassette 53, the lower cassette 54, the paper cassette 57 and the large capacity feeder 55, there are provided pickup rollers 63 for taking out the sheets P one by one from the cassette or the large capacity feeder. Have been. The transport path 58 is provided with a number of paper feed roller pairs 64 for transporting the copy sheet P taken out by the pickup roller 63 through the transport path 58.

A pair of registration rollers 65 is provided upstream of the photosensitive drum 44 in the transport path 58. The registration roller pair 65 corrects the inclination of the copy paper P taken out, aligns the leading end of the toner image on the photosensitive drum 44 with the leading end of the copy paper P, and adjusts the moving speed of the peripheral surface of the photosensitive drum 44 to The copy paper P is fed to the transfer unit at the same speed. A pre-alignment sensor 66 for detecting the arrival of the copy sheet P is provided in front of the registration roller pair 65, that is, on the side of the feed roller 64.

The copy paper P taken out one by one from each cassette or the large-capacity feeder 55 by the pickup roller 63 is sent to the registration roller pair 65 by the paper supply roller pair 64. Then, the copy paper P is sent to the transfer section after the leading end is aligned by the registration roller pair 65.

In the transfer section, the developer image formed on the photosensitive drum 44, that is, the toner image, is transferred onto the sheet P by the transfer charger 48. The copy paper P on which the toner image has been transferred is separated from the peripheral surface of the photosensitive drum 44 by the action of the separation charger 47 and the separation claw 49,
The sheet is conveyed to the fixing device 60 via a conveyance belt 67 constituting a part of the conveyance path 52. Then, after the developer image is fused and fixed to the copy paper P by the fixing device 60, the copy paper P is discharged onto the finisher 150 through the discharge port 61 by the paper feed roller pair 68 and the paper discharge roller pair 69.

Under the transport path 58, the copy paper P passing through the fixing device 60 is turned over and again
5 is provided with an automatic double-sided device 70 for feeding. The automatic duplexing device 70 includes a temporary stacking unit 71 for temporarily stacking the copy sheets P, and a reversing path 72 that branches off from the transport path 58 and reverses the copy sheet P that has passed through the fixing device 60 and guides the copy sheet P to the temporary stacking unit 71. A pickup roller 73 for taking out the copy papers P accumulated in the temporary accumulation section one by one; and a paper feed roller 75 for feeding the taken out paper to a pair of registration rollers 65 through a transport path 74. Also, the transport path 58
The copy paper P is provided at a branch portion between the
A distribution gate 76 for selectively distributing to one or the inversion path 72 is provided.

When performing double-sided copying, the copy paper P that has passed through the fixing device 60 is guided to a reversing path 72 by a sorting gate 76, is temporarily accumulated in a reversed state in a temporary accumulation section 71, and is then picked up. The sheet is sent to a pair of registration rollers 65 through a conveyance path 74 by a roller 73 and a pair of sheet feeding rollers 75. Then, after the copy paper P is aligned by the registration roller pair 65, the copy paper P is sent to the transfer unit again, and the toner image is transferred to the back surface of the copy paper P. Thereafter, the copy sheet P is discharged to the finisher 150 via the transport path 58, the fixing device 60, and the discharge roller 69.

The finisher 150 is for stapling and storing the discharged partially structured documents in a unit. Each time the copy sheet P to be stapled is discharged from the sheet discharge port 61, the copy sheet P is brought closer to the side to be stapled by the guide bar 151 and aligned. When all the sheets have been ejected, the paper holding arm 152 suppresses the part of the ejected copy sheet P, and a stapler unit (not shown) performs stapling. Thereafter, the guide bar 151 is lowered, and the stapled copy paper P is discharged to the finisher discharge tray 154 by the finisher discharge roller 155 in a unit. Finisher discharge tray 154
The amount of decrease is determined to some extent by the number of copy sheets P to be discharged, and decreases step by step every time a part of the copy paper P is discharged. Further, the guide bar 151 for aligning the copy sheet P to be discharged is located at such a height that it does not hit the already stapled copy sheet P placed on the finisher discharge tray 154.

Further, the finisher discharge tray 154 is
In the sort mode, it is connected to a shift mechanism (not shown) that shifts every part (for example, in four directions of front, rear, left and right).

An operation panel 80 for inputting various copy conditions, a copy start signal for starting a copy operation, and the like is provided on an upper front portion of the apparatus main body 10. As shown in FIG. 5, the operation panel 80 includes a numeric keypad 81, a copy key 82, a status display unit 83, a liquid crystal display unit 84, an original size setting key 85, a paper size setting key 86, a density display unit 87, and a density setting key 88. , And a magnification setting key 89.

The ten keys 81 are used to set the number of documents and the number of copies. The copy key 82 is for instructing the start of copying. The status display unit 83 is for guiding and displaying the selection status of the paper feed cassette, a document, a paper jam, and the like.

The liquid crystal display 84 displays the number of documents and the number of copies, displays an error message, and provides various operation guidance. The liquid crystal display section 84 includes
A touch panel is provided so that various operation instructions such as input of the selection keys can be input.

The document size setting key 85 is for setting the size of the document D. The paper size setting key 86 is
This is for setting the size of the paper P. Density display section 87
Indicates the copy density set by the density setting key 88.

A magnification setting key 89 is for setting a copy magnification. The operation panel 80 is a panel C
The whole is controlled by the PU 80a.

FIG. 6 is a block diagram schematically showing a signal flow for electrical connection and control of the digital copying machine in FIG. According to FIG. 6, in the digital copying machine, the main CPU 9 in the main control unit 90 is provided.
1 and a scanner CPU 100 of the scanner unit 4 and a printer CPU 110 of the printer unit 6. The main CPU 91 performs bidirectional communication with the printer CPU 110 via the shared RAM 95, and the main CPU 91 issues an operation instruction and the printer CPU 100
Returns the status status. Printer C
The PU 110 and the scanner CPU 100 perform serial communication, the printer CPU 110 issues an operation instruction, and the scanner CPU 100 returns a status.

The operation panel 80 is connected to the main CPU 91. The main control unit 90 includes a main CPU 91, R
OM92, RAM93, NVM94, shared RAM95,
The image processing unit 96 includes a page memory control unit 97 and a page memory 98.

The main CPU 91 controls the entire main control section 90. The ROM 92 stores a control program and the number of drive steps for the scanner motor 37 at the time of reading and scanning for each document size. RA
M93 is for temporarily storing data.

NVM (lasting random access memory: n)
The on-volatile RAM 94 is a non-volatile memory backed up by a battery (not shown), and retains data on the NVM 94 when the power is turned off.

The shared RAM 95 is used for performing bidirectional communication between the main CPU 91 and the printer CPU 110. The image processing unit 96 performs trimming, masking, enlargement and reduction of an image, and the like.

The page memory control section 97 stores and reads out image data in the page memory 98. The page memory 98 has an area in which image data for a plurality of pages can be stored, and is formed so that data obtained by compressing image data from the scanner unit 4 can be stored for each page.

The scanner unit 4 includes a scanner CPU 100 for controlling the entire scanner unit 4, a ROM 101 for storing a control program and the like, and a RAM 10 for data storage.
2. CCD driver 10 for driving CCD sensor 34
3. A scanner motor driver 1 for controlling the rotation of a scanner motor 37 for moving the exposure lamp 25 and the first and second carriages 27, 28 of the mirrors 26, 30, 31 and the like.
04, an A / D conversion circuit for converting an analog signal from the CCD sensor 34 into a digital signal, and a CCD caused by a variation in the CCD sensor 34 or a change in ambient temperature.
An image correction unit 105 comprising a shading correction circuit for correcting a threshold level fluctuation with respect to an output signal from the sensor 34 and a line memory for temporarily storing a shading-corrected digital signal from the shading correction circuit; It is composed of a remote maintenance circuit 106 for transmitting the details of the abnormality (with date and time) via a telephone line by telephone or facsimile, an exposure lamp driver 107 for turning on the exposure lamp 25, and the above-mentioned reflection type photo interrupters 35 and 36. . The remote maintenance circuit 106 has, for example, a facsimile function of transmitting the contents of the abnormality to a predetermined dial number.

The printer unit 6 includes a printer CPU 110 for controlling the entire printer unit 6, a ROM 111 storing a control program and the like, and a RAM 11 for storing data.
2. Laser driver 113 for turning on / off light emission by semiconductor laser 41, polygon motor driver 11 for controlling rotation of polygon motor 39 of laser unit 40
4. paper transport unit 115 for controlling transport of paper P by transport path 58, charging device 45, developing device 46, transfer charger 4
Developing process unit 11 for performing charging, developing, and transferring using 8
6, a fixing control unit 117 for controlling the fixing unit 60, and an option unit 118.

The image processing section 96 and the page memory 9
8. The image correction unit 105 and the laser driver 113 are connected by an image data bus 120. Main CP
A switching signal from the forward scan to the back scan which is transmitted from U91 to the scanner motor driver 104 via the scanner CPU 100 after the transmission of the final pulse signal of the motor phase current setting signal, the drive pulse signal, and the drive pulse signal as the set current value. Is supplied.

That is, the reflection type photo interrupter 3
Depending on the on / off state of the photointerrupters PD5 and PD36, as shown in FIG.
A4, A5, B4, B5, B6, A4-R, A5-R,
B5-R and B6-R are detected.

The main CPU 91 controls the movement of the first carriage 27 by driving the scanner motor 37 by the number of steps corresponding to the determined document size during scanning for reading the document D (during forward movement). It is supposed to do.

Next, the image reading process in the above configuration will be described with reference to the flowchart shown in FIG. At this time, the current value (corresponding to the torque) for the scanner motor 37 by the scanner motor driver 104 is 1.0 A (ampere) at the time of the initial setting.

In such a state, the document D is placed on the document placing table 12, and after the number of sheets is set, the copy key 82 is turned on (ST1). Then, the main CP
U91 controls the scanner motor driver 104 and moves the first carriage 27 with the exposure lamp 25 in the scanner unit 4 turned off, thereby performing prescan (ST2). As a result, the main CPU 91 determines the document size based on the ON / OFF state of the photo interrupters PD of the reflection type photo interrupters 35 and 36 (ST2). Thereafter, the main CPU 91 controls the scanner motor driver 104 to return the first carriage 27 to the initial position.

Next, the main CPU 91 drives the scanner motor driver 104 by the number of drive steps corresponding to the determined document size, thereby rotating the scanner motor 37 and starting the movement of the first carriage 27, and The exposure lamp 25 is turned on (ST3).

The light from the exposure lamp 25 is applied to the original D placed on the original placing table 12 with the movement of the first carriage 27, so that this reflected light is 1st, 2nd, 3rd mirrors 26, 30, 3
1. The light is guided to the CCD sensor 34 via the imaging lens 32. As a result, the read signal as an output signal from the CCD sensor 34 is A / D converted by the image correction unit 105,
After the shading correction, it is output via the image bus 120. The output image signal is sent to the printer unit 6.
Or stored in the page memory 98, and then printed by the printer unit 6.

When the first carriage 27 moves by the number of drive steps described above, the main CPU 91 determines the presence or absence of the document D by checking whether the phototransistor PD of the reflective photointerrupter 35 is on. , Manuscript D
When it is determined that there is no symbol, it is determined that the reading scan has been completed normally (ST4).

As described above, when the normal completion of the reading scan is determined, the main CPU 91 operates the scanner motor driver 10.
4 to start the back scan operation of returning the first carriage 27 to the initial position (ST5).

Then, the main CPU 91 checks whether or not the copying of the set number has been completed (ST6). If not completed, the process returns to the step 3, and if completed, the process is terminated.

In step 4, when the presence of the original D is determined and the reading scan is abnormal due to insufficient torque of the scan motor 37 or the like, the main CPU 91
Outputs the first scan scanning abnormality to the remote maintenance circuit 106 (ST7). Thus, the remote maintenance circuit 106 creates a sentence for guiding the first scan scanning abnormality, and transfers the created content to a predetermined dial number using a facsimile function and the content of the abnormality via a telephone line. Send by facsimile.

Further, the main CPU 91 determines that the reading scan is abnormal for the first time (ST8), and increases the current value (corresponding to the torque) of the scan motor driver 104 to the scanner motor 37 by 0.5A to 1.5A. (ST
9), the number of continuous copies is set to 20 (ST1)
0).

As a result, the number of continuous copies set at the start of copying is thereafter limited to 20. By limiting the number of continuous copies, as shown in FIG.
Although the temperature of the scanner motor driver 104 rises slightly from the safe range, it does not exceed the temperature rise limit value because it has a temperature rise margin.

In the state where the current value of the scanner motor driver 104 for the scan motor 37 is set to 1.5 A, the existence of the document D is determined in step 4 and the scanner motor 37 becomes abnormal due to insufficient torque or the like. When the main CPU 91 operates and determines that the reading scan is abnormal, the main CPU 91 outputs the second scan scanning abnormality to the remote maintenance circuit 106 (ST7). This allows
The remote maintenance circuit 106 creates a sentence for guiding the second error in the reading scan, and transmits the created content to a predetermined dial number by facsimile using a facsimile function via a telephone line. .

Further, the main CPU 91 determines the second abnormality of the reading scan (ST11), and increases the current value (corresponding to the torque) of the scanner motor driver 104 for the scanner motor 37 by 0.5A to 2.0A ( ST1
2), the number of continuous copies is set to 10 (ST1)
3).

As a result, the number of continuous copies set at the start of copying is thereafter limited to 10. By limiting the number of continuous copies, as shown in FIG.
Although the temperature of the scan motor driver 104 rises slightly from the safe range, it does not exceed the temperature rise limit value because it has a temperature rise margin.

Further, with the current value of the scanner motor driver 104 for the scanner motor 37 set to 2.0 A, in step 4
Is determined and the scanner motor 37 abnormally operates due to insufficient torque or the like, and determines that the reading scan is abnormal, the main CPU 91 outputs the third scan scanning abnormality to the remote maintenance circuit 106 (ST7). As a result, the remote maintenance circuit 106 performs the third scanning operation.
A sentence for guiding the second abnormality is created, and the created content is transmitted by facsimile.

Further, the main CPU 91 determines the third abnormality of the reading scan (ST11), and the change of the current value (corresponding to the torque) to the scanner motor 37 by the scanner motor driver 104 is a limit value and cannot be changed (service Is displayed on the liquid crystal display unit 84 (ST14), the copying operation is interrupted, and the subsequent copying operation is prohibited.

In the above embodiment, the case where the set number of continuous copies is limited in accordance with the current value of the scanner motor driver 104 with respect to the scan motor 37 has been described.
The copying process may be interrupted (between steps 5 and 6 in the flowchart) each time the number of sheets reaches 10 or 10), and the temperature of the scanner motor 37 may be kept within a safe range. In this case, during the interruption, the effect of the interruption is displayed on the liquid crystal display unit 84 as a guide.

As described above, even when the scanner motor stops halfway during the scanning operation due to insufficient torque, the torque of the scanner motor can be increased from the next scanning operation by increasing the set current of the scanning motor. And the scanning operation can be performed without any problem. At the same time, by using the remote maintenance circuit or the like to immediately contact the service person, the reliability is high for the user.

In the above embodiment, a stepping motor is used as the scanner motor, but a DC motor may be used. When this DC motor is used, the movement control is performed by the control frequency instead of the movement control by the number of drive steps.

[0076]

As described above in detail, according to the present invention, an image reading apparatus, an image forming apparatus, and an image reading method capable of performing a normal scanning operation when a torque shortage of a scanner motor occurs. Can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a digital copying machine for describing an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a main part of a scanner unit.

FIG. 3 is a top view for explaining a relationship between placement positions of documents of various sizes on a document placement table and detection positions of prescan by two reflection-type photointerrupters.

FIG. 4 is a diagram for explaining a temperature rise state of the scanner motor driver with respect to the number of continuous copies at each set current of the scanner motor.

FIG. 5 is a top view illustrating a configuration of an operation panel.

FIG. 6 is a block diagram showing a schematic configuration of a control circuit of the digital copying machine.

FIG. 7 is a flowchart illustrating an image reading process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 4 ... Scanner part 6 ... Printer part 12 ... Document mounting table 25 ... Exposure lamp 27 ... First carriage 34 ... CCD sensor 35, 36 ... Reflection type interrupter 37 ... Scanner motor 80 ... Operation panel 84 ... Liquid crystal display part 90 ... Main Control unit 91: Main CPU 100: Scanner CPU 104: Scanner motor driver 106: Remote maintenance circuit 110: Printer CPU

Claims (12)

[Claims] A document table on which a document is placed; scanning means for reading and scanning the document placed on the document table; moving means for moving the scanning means relative to the document table. A driving means for driving the moving means by a first driving force so that the scanning means moves the document size equivalent amount; and a driving means for moving the scanning means with respect to the moving means, the scanning means moving the document size equivalent amount. Detecting means for detecting that the scanning means has a moving amount different from the document size equivalent when the first driving force is supplied, and based on the detection of the detecting means, An image reading apparatus, comprising: changing means for changing the driving force so that the driving means drives with the second driving force so as to optimize the driving force supplied to the moving means. 2. A document table on which a document is placed, scanning means for reading and scanning the document placed on the document table, and moving means for moving the scanning means relative to the document table. A driving means for driving the moving means by a predetermined driving force so that the scanning means moves the document size equivalent amount; and the driving means moves the scanning means relative to the moving means by the document size equivalent amount. Detecting means for detecting that the scanning means has a movement amount different from that corresponding to the document size when only a predetermined driving force is supplied; and reporting an abnormal state based on the detection of the detecting means. An image reading apparatus comprising: a notifying unit. 3. A document table on which a document is placed, scanning means for reading and scanning the document placed on the document table, and moving means for moving the scanning means relative to the document table. A first method for detecting the size of a document placed on the platen;
A driving means for driving the moving means by a first driving force so that the scanning means moves by a document size equivalent amount according to a detection result by the first detecting means; and A second detecting means for detecting that the scanning means has not moved by an amount corresponding to the document size when the scanning means supplies a first driving force by an amount corresponding to the document size; On the basis of the detection by the second detection unit, the driving force is changed so that the driving unit increases the driving force supplied to the moving unit by a predetermined amount and drives with the second driving force during the subsequent scanning operation. An image reading apparatus comprising: 4. A document table on which a document is placed, scanning means for reading and scanning the document placed on the document table, and moving means for moving the scanning means relative to the document table. A first method for detecting the size of a document placed on the platen;
A driving means for driving the moving means by a first driving force so that the scanning means moves by a document size equivalent amount according to a detection result by the first detecting means; and A second detecting means for detecting that the scanning means has not moved by an amount corresponding to the document size when the scanning means supplies a first driving force by an amount corresponding to the document size; On the basis of the detection by the second detection unit, the driving force is changed so that the driving unit increases the driving force supplied to the moving unit by a predetermined amount and drives with the second driving force during the subsequent scanning operation. An image reading apparatus, comprising: a changing unit that performs a continuous scanning by the scanning unit when the driving force supplied by the driving unit is increased by the changing unit. 5. A document table on which a document is placed, scanning means for reading and scanning the document placed on the document table, and moving means for moving the scanning means relative to the document table. A first method for detecting the size of a document placed on the platen;
A driving means for driving the moving means by a first driving force so that the scanning means moves by a document size equivalent amount according to a detection result by the first detecting means; and A second detecting means for detecting that the scanning means has not moved by an amount corresponding to the document size when the scanning means supplies a first driving force by an amount corresponding to the document size; And an informing means for informing that an abnormal state is detected based on the detection by the second detecting means. 6. A document table on which a document is placed, reading means for reading an image from the document placed on the document table, moving means for moving the reading means along the document table, A plurality of detecting means provided on the reading means for detecting the presence or absence of a document placed on the document table; and moving these detecting means by the moving means, based on a detection signal from the detecting means. First determining means for determining the size of the document placed on the platen, control means for controlling the movement of the moving means by the size of the document according to the determination result by the first determining means, An output unit that outputs a read output from the reading unit as a reading result when the moving unit is controlled to move by the control unit; and the control unit controls the moving unit to move by the document size. When the presence of a document is detected by the detecting means, a second determining means for determining an abnormality of the moving means; and when the second determining means determines an abnormality of the moving means, An image reading apparatus, comprising: changing means for changing the driving force of the moving means in a stepwise manner. 7. A document table on which a document is placed, reading means for reading an image from the document placed on the document table, moving means for moving the reading means along the document table, A plurality of detecting means provided on the reading means for detecting the presence or absence of a document placed on the document table; and moving these detecting means by the moving means, based on a detection signal from the detecting means. First determining means for determining the size of the document placed on the platen, control means for controlling the movement of the moving means by the size of the document according to the determination result by the first determining means, An output unit that outputs a read output from the reading unit as a reading result when the moving unit is controlled to move by the control unit; and the control unit controls the moving unit to move by the document size. When the presence of a document is detected by the detecting means, a second determining means for determining an abnormality of the moving means; and when the second determining means determines an abnormality of the moving means, Changing means for changing the driving force of the moving means in a stepwise manner; and notifying means for notifying the limit of the change by the changing means when the driving force of the moving means changed by the changing means reaches a limit value. An image reading apparatus, comprising: 8. A document table on which a document is placed, reading means for reading an image from the document placed on the document table, moving means for moving the reading means along the document table, A plurality of detecting means provided on the reading means for detecting the presence or absence of a document placed on the document table; and moving these detecting means by the moving means, based on a detection signal from the detecting means. First determining means for determining the size of the document placed on the platen, control means for controlling the movement of the moving means by the size of the document according to the determination result by the first determining means, An output unit that outputs a read output from the reading unit as a reading result when the moving unit is controlled to move by the control unit; and the control unit controls the moving unit to move by the document size. When the presence of a document is detected by the detecting means, a second determining means for determining an abnormality of the moving means; and when the second determining means determines an abnormality of the moving means, And an informing means for informing the external device of the abnormality of the moving means. 9. A document table on which a document is placed, scanning means for reading and scanning the document placed on the document table, and moving means for moving the scanning means relative to the document table. A driving means for driving the moving means by a first driving force so that the scanning means moves the document size equivalent amount; and a driving means for moving the scanning means with respect to the moving means, Detecting means for detecting that the scanning means has a moving amount different from the document size equivalent when the first driving force is supplied, and based on the detection of the detecting means, Changing means for changing the driving force such that the driving means is driven by the second driving force so as to optimize the driving force supplied to the moving means; and the moving means driven by the driving means performs the scanning. Move the means An image forming apparatus, comprising: an image forming unit that forms an image of a document obtained by the above on a medium on which an image is to be formed. 10. A document table on which a document is placed, scanning means for reading and scanning the document placed on the document table, and moving means for moving the scanning means relatively to the document table. A driving means for driving the moving means by a first driving force so that the scanning means moves the document size equivalent amount; and a driving means for moving the scanning means with respect to the moving means, the scanning means moving the document size equivalent amount. Detection means for detecting that the scanning means has a movement amount different from the document size equivalent when the first driving force is supplied as much as possible; and Notifying means for notifying, and image forming means for forming an image of a document obtained by moving the scanning means by the moving means driven by the driving means on an image forming medium. An image forming apparatus symptoms. 11. A document table on which a document is placed, scanning means for reading and scanning the document placed on the document table, and moving means for moving the scanning means relative to the document table. A driving means for driving the moving means with a first driving force so as to move the scanning means by an amount corresponding to the document size, wherein the driving means corresponds to the moving means and the scanning means corresponds to the document. When the first driving force is supplied by an amount equivalent to the size, the scanning unit detects that the amount of movement is different from the amount corresponding to the size of the original. Means to optimize the driving force supplied to the moving means by the means.
An image reading method, wherein the driving force is changed so as to be driven by the driving force. 12. A document table on which a document is placed, scanning means for reading and scanning an image from the document placed on the document table, and movement for moving the scanning means relative to the document table. And a driving means for driving the moving means with a first driving force so that the scanning means moves by an amount corresponding to the document size. When the first driving force is supplied by the amount corresponding to the document size, the scanning unit detects that the moving amount is different from the document size, and based on the detection, the abnormal state is determined. Providing an image reading method.