JPH09127743A - Image recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a recorded matter the same as a document in spite of the dispersion of a transfer material by starting the feed of the transfer material by a resist roller in timing obtained by calculating and correcting a distance between the detected leading edge of the document and the position of a standard leading edge. SOLUTION: A document detection control part 60 controls a document leading edge sensor to measure reflection density, compares the absolute value of the measured reflection density with that of known reflection density data on an ADF document feeding belt part, the back surface of a document butting scale 6 stored in a 2nd memory 61 so as to specify the leading edge of the document. Next, from the data on the leading edge of the document, a distance from the document butting scale to the leading edge of the document is calculated and the signal is inputted in a system control part 50 through an input device 53. The system control part 50 compares a distance to the leading edge of the doucment with document standard leading edge distance stored in a 1st memory. In the case a difference is found between both distances, the refeeding timing from the resist roller is changed by an amount in accordance with the difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading section for reading a document set on a platen with its front end aligned with a standard front end alignment position, and image forming for forming an image of the read document on an image carrier. And an image recording apparatus that records an image formed by the image forming unit on a transfer material fed through a registration roller.

[0002]

2. Description of the Related Art Conventionally, an image recording apparatus such as a copying machine feeds a transfer material from a registration roller at an absolute feeding timing regardless of the setting position of an original, and transfers the image formed on the transfer material by an image forming unit. It is transcribed. For this reason, when a document is set by an automatic document feeder (ADF) or manually, if the document position is correct but it is displaced from the position corresponding to the document size, the image is transferred onto the transfer paper without correcting the displacement. Since it is recorded, it has become a defective copy. Moreover, there is a problem that a defective copy is noticed after the copying is completed.

As a device for correcting a document set deviation,
Japanese Unexamined Patent Publication No. 2-25893 discloses a device that detects the inclination of a document, rotates a suction rotation member that sucks the document by the amount of the inclination, and then starts reading an image.

[0004]

However, the above-mentioned reading device corrects an original set at an inclination, and corrects an original set at a position deviated from the position corresponding to the original size even if the orientation is correct. Not a thing,
Even if it can be applied to such a set deviation, there is a problem that the prescan is performed in order to detect the set deviation of the tilted document, and the copying speed becomes slower accordingly. Further, the above-mentioned reading device moves the position of the original document in order to correct the misalignment of the original document, which requires a suction rotation member and an original document rotation motor for driving the suction rotation member, which makes the structure complicated and expensive, and has a high reliability. There was also a problem that it was scarce.

The present invention has been made in view of the above problems, and automatically obtains the same image recorded matter as a document set even if the document is set in a proper direction and displaced from the position corresponding to the document size. An object of the present invention is to provide an image recording device capable of performing the above.

[0006]

In order to solve the above-mentioned problems, the present invention comprises an image reading section for reading an original set on an original platen with its front end aligned with a standard front end alignment position.
An image recording apparatus having an image forming unit for forming an image of a read original on an image carrier, and recording the image formed by the image forming unit on a transfer material fed through a registration roller, The registration roller is provided with a leading edge detector that detects the leading edge position of the original document set on the document table, and the registration roller is calculated at the timing when the distance between the leading edge of the original document detected by the leading edge detector and the standard leading edge position is calculated and corrected. It is characterized in that it has a position correction control means for starting the feeding of the transfer material by.

In order to solve the above-mentioned problems, according to the present invention, an image reading unit for reading a document set on a document table with its front end aligned with a standard front end alignment position, and an image of the read document on an image carrier. An image forming unit to be formed and a changing unit capable of changing the size, position, etc. of an image to be selectively recorded by an external input unit are provided, and the image formed by the image forming unit is fed through a registration roller. An image recording apparatus for recording on a transferred transfer material is provided with a leading edge detector that detects a leading edge position of an original document set on the original document table, and the leading edge of the original document detected by the leading edge detector and the standard leading edge position. The position correction control means starts the feeding of the transfer material by the registration roller at the timing when the distance between the two is calculated and corrected, and when the change means is selected, the position correction control means changes the position. It is characterized in that the start of the feeding of the transfer material by the registration rollers at a timing obtained by adding the change.

The present invention is effective when the detecting means for detecting the leading end position of the original document is integrally supported by the scanner device for reading and scanning the original document. Further, the present invention is effective when the detection means for detecting the leading edge position of the original document also serves as a sensor for reading the original image.

Further, according to the present invention, when the torque transmission means is rotatably mounted coaxially with the driven roller and a gear meshing with the drive gear and an angular velocity difference between the gear and the driven roller are generated. A friction clutch that produces torque is effective.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing a digital copying machine as an image recording apparatus according to the present invention.

In FIG. 1, a digital copying machine 1 includes an image reading section 10 for reading an original (not shown) on a contact glass 2 which is an original placing table, and the image reading section 10.
An image writing unit 20 that modulates laser light in accordance with an image signal from the device and writes the light on a photoconductor 31 described later, and an image that visualizes an electrostatic latent image formed on the photoconductor 31 and transfers it to a transfer sheet. The image forming unit 30 includes a forming unit 30 and a paper feeding unit 40 that feeds a transfer sheet to the image forming unit 30. And contact glass 2
In the case of this example, the automatic document feeder (ADF) 3 is mounted on the upper side, but a document pressure plate may be used instead of the ADF 3.

As shown in FIG. 2, the image reading section 10 irradiates a document (not shown) placed on the contact glass 2 with the light of the light source 11, and the reflected light from the document is the first.
~ 3 Condenser lens 1 reflected by mirrors 12, 13, 14
After passing through 5, the light enters the CCD 16 as a sensor for reading the original. A signal from the CCD 16 which converts the reflected light from the document into an electric signal corresponding to the density of the original is amplified by an amplifier circuit (not shown) and converted into a digital signal by an A / D converter circuit (not shown). . The light source 11 and the first mirror 12 are mounted on a first scanner 17, and the first scanner 17 has a document leading edge sensor 4 as a leading edge detector.
Is also installed. The document leading edge sensor 4 is a density measuring sensor that includes a light emitting unit 4a and a light receiving unit 4b that receives the reflected light of the light emitting unit 4a, and that electrically converts the amount of light reflected from the document surface or the like. In addition, reference numeral 18 is the second and third mirrors 1.
It is a second scanner equipped with the first and second scanners 3, 14,
The scanner 17 and the second scanner 18 are collectively referred to as a document scanner.

The image writing unit 20, the image forming unit 30, and the paper feeding unit 40 are known per se, and the image writing unit 20 is known.
Is irradiated with a laser beam modulated by a semiconductor laser unit (not shown) onto a polygon mirror 22 that is rotated at a constant speed by a polygon motor 21, and the laser beam reflected by the polygon mirror 22 is fθ lens (not shown). No)
Thus, the surface of the photoconductor 11 is exposed by correcting the photoconductor 31 at equal intervals in the main scanning direction and also correcting the inclination of the reflecting surface of the polygon mirror 22.

When the photosensitive member 31 of the image forming unit 30 is rotated clockwise, the photosensitive member 31 charged by the charging charger 32 is irradiated with laser light from the image writing unit 20 to form an electrostatic latent image. To be done. The electrostatic latent image is developed into a toner image by the developing device 33, and the toner image is transferred by the transfer unit 34 onto the transfer material fed from the paper feeding unit 40. The toner remaining on the photoconductor 11 without being transferred is removed by the cleaning device 35 to prepare for the next copying operation.

Further, in the case of the present example, the paper feeding section 40 is
The four-stage paper feed tray 41 and the double-sided tray 42 are provided. The transfer material fed from each tray is temporarily stopped by the registration roller 43, and thereafter the registration roller 43 synchronized with the toner image formed on the photoconductor 31 is formed. The rotation drive is started and the sheet is fed to the transfer unit 34.

The transfer material on which the toner image has been transferred is separated from the photoconductor 31 and sent to the fixing section 5, and the fixing section 5
After being fixed by (1), it is discharged to the outside of the machine or conveyed to a double-sided tray.

FIG. 3 is a block diagram showing a control system related to the position correction control means of this digital copying machine. In FIG. 3, a system control unit 50 for controlling the entire copying machine is provided, and the system control unit 50 includes a registration roller rotation stop control unit, a scanner drive stop control unit, an image forming process control unit, a document presence / absence warning display control unit, and the like. Control load 5
2 is controlled via the output device 51. Further, the system control unit 50 is provided with a first memory 53 in which the standard document leading edge distance, the scanner driving timing, the sensor reading timing, the transfer material registration standby timing, and the registration roller restart standard timing are stored. The operation timing of is controlled based on the signal from the first memory 53.

Reference numeral 60 is an original detection control unit,
The original detection control unit 60 has a second memory 61 and a CPU 62 independent of the system control unit 50. The second memory 61 has a density inside the machine, a lower surface density of the original scale 6,
Data of the standard document background density, the ADF standard density, and the ADF open standard density are stored. Further, the CPU 62 is configured to detect the presence / absence of a document, the size of the document, the leading edge of the document described later, and the like, and input these data to the system control unit 50 via the input device 63.

Next, a method of detecting the leading edge of the original by the original detection control unit 60 will be described. As a first method, the contact is scanned on the lath 2 by the document leading edge sensor 4 to measure its reflection density, and the reflection density and the ADF document conveyance belt section of the second memory 61, the back surface of the document abutting scale 6, By comparing the absolute value with the known reflection density data inside the machine, the leading edge of the document can be specified. At this time, the high reflection density portion is often a blank area at the leading edge of the document.

As another method, the document leading edge sensor 4
Then, the contact scans the lath 2 to measure the reflection density, detects a portion where the measurement result changes abruptly, and identifies the document front end from the density change of the boundary line. That is, as shown in FIG. 4, the leading edge of the document is specified from the inside of the machine (running scan portion), the back surface of the document abutting scale 6, the ADF document transport belt portion, and the density change of the boundary line of the document leading edge margin area. This tip detection can be performed without using the data in the second memory 61.
If the difference in density between the original 7 and the back surface of the original abutting scale 6 and the difference in density between the original 7 and the original conveying belt of the ADF 2 are larger than other boundaries, an appropriate threshold value is set and the threshold value is exceeded. The boundary can be specified by, for example, the leading edge of the document. In order to clarify the boundary density difference, for example, AD
It is advantageous that the F document transport belt portion is colored in yellow instead of white, or the back face of the document abutting scale 6 has a metallic luster.

In this way, the distance from the document abutting scale 6 to the document leading edge is calculated from the detected document leading edge data, and this distance signal is input to the system control unit 50 via the input device 53. The system controller 50 compares the detected distance to the leading edge of the document with the standard leading edge distance stored in the first memory, and if there is a difference between the two distances, the registration roller 43 supplies a portion corresponding to the difference. Control to change the re-feed timing of. Therefore, the manuscript 7
Even if the sheets are misaligned and set, the image is automatically controlled to be copied at a position matched with the original. That is,
When the leading edge of the document set on the contact glass 2 is 1 cm away from the document abutting scale 6, the leading edge correction control is performed such that the re-feeding timing from the registration roller 43 is fed by 1 cm for feeding.

The tip correction control thus performed is always kept in the ON state during normal copying, and a switch (not shown) for canceling the tip correction control is provided on an operation panel (not shown). It is convenient to configure the release switch to be turned on only when is unnecessary.

Most of the copying machines have a function of changing copying conditions such as a variable magnification function, a binding margin adjusting function, and an image position shifting function, and such a function is selected by an external input. In this case, the re-feed timing from the registration roller 43 is also changed according to the copying conditions. Therefore, when the function to change the copy condition is selected,
When the document is set with deviation, the control of the leading edge correction is performed in consideration of the copy condition of the selected function in the control of the leading edge correction. That is, even if the original 7 is set with deviation, it is re-fed from the registration roller 43 so that the same original as the original obtained by setting the original 7 at the regular position and obtained based on the selected copy condition can be obtained. It is configured to change the timing.

FIG. 5 is a flow chart showing a copy job related to the position correction control means of the digital copying machine. In FIG. 5, when a copy start switch (not shown) is pressed, the copy job starts.

First, the document scanner starts scanning (step 1). At this time, a document presence / absence detection sensor (not shown) compares it with the standard reflection density data of the pressure plate in the memory 2 or the ADF document transport belt shown in FIG. The presence or absence of the original is determined (step 2). The document leading edge sensor 4 may be used as the document presence detection sensor. When there is no original, a warning message is displayed on the operation panel display and the copy job ends (step 15). If there is a document, a transfer material having the same size as the document or a designated size is fed from the paper feeding unit 40 (step 3). The fed transfer material is temporarily stopped by the registration roller 43 and stands by there (step 4). Next, by the method described above, the contact glass 2
The leading edge position of the document set above is detected (step 5), and the detected document leading edge position is compared with the standard document leading edge position (step 6). As a result, if the leading edge of the set original is at the position abutting the original abutting scale 6, there is no difference from the standard original leading edge position and the deviation width is zero, but the leading edge of the original is the original abutting scale. When it is set apart from 6, the distance which is the deviation width is detected.

Next, it is judged whether or not the leading edge correction of the original is selected (step 7). When the leading edge correction of the original is not selected, copying conditions such as scaling, binding margin adjustment, image position shift, etc. Is determined separately (step 9). When the copy condition by external input is not selected, the registration roller 4 is set at the timing of normal control.
3, the rotation of the transfer material feeding is started, and when the copying condition by the external input is selected, the rotation of the transfer material feeding by the registration roller 43 is started at the timing of controlling the copying condition (step 11). . After that, the copy process is executed (step 12), and the copy is discharged (step 1).
3) The copy job is completed after the original scanner is returned to the home position and stopped (step 14). Therefore, if the set original is misaligned while the front end correction of the original is cancelled, a copy in the misaligned state can be obtained.

In step 7, if correction of the leading edge of the original is selected, registration roller rotation start timing correction processing for correcting the registration roller rotation start timing by the deviation width is performed (step 8). Subsequently, it is determined whether or not copying conditions such as variable magnification, binding margin adjustment, image position shift, etc. are separately input (step 9). At this time, if the copying condition by the external input is not selected, the rotation of the transfer material feeding by the registration roller 43 is started at the correction timing based on the correction process (step 11), and then the copying process is executed (step 12), Eject copy (step 13), return / stop original scanner to home position (step 1)
After 4), the copy job ends.

Further, when the leading edge correction of the original is selected and the copying condition by the external input in step 9 is selected, the registration roller rotation start timing is selected to be the leading edge correction of the deviation width. A correction process taking into account the copy conditions is executed (step 10). And
The registration roller 4 is corrected at the correction timing based on the correction process.
The rotation of the transfer material feeding by 3 is started (step 1
1) After that, the copy process is executed (step 12), the copy is discharged (step 13), the original scanner is returned to the home position and stopped (step 14), and the copy job is completed.

With this configuration, even if a document is erroneously set apart from the document abutting scale 6, the distance is detected and the leading edge is corrected by changing the distance by the rotation start timing of the registration roller 43. Done. Therefore, it is possible to significantly reduce the occurrence of miscopying in which the position of the original image is displaced with respect to the transfer material. Moreover, when the variable magnification function, the binding margin adjusting function, the image position shifting function, etc. are selected by external input and the original is misaligned and set, the leading edge correction is performed in consideration of the copy condition of the selected function. Therefore, even when the function is selected, it is possible to significantly reduce the occurrence of miscopying in which the position of the original image is displaced with respect to the transfer material. Furthermore, this tip correction can also be canceled by operating the switch,
It can respond to every request of the operator.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and various modifications can be made. For example, in the above embodiment, the document leading edge sensor 4 is mounted on the document scanner, but the document leading edge sensor 4 has a light emitting portion 4a and a light receiving portion 4b as shown in FIG.
May be fixed to the machine frame or the like. However, in this case, in order to improve accuracy, it is necessary to arrange a plurality of sensors as continuously as possible. Therefore, it is more advantageous than the one installed in the scanner in the work of wiring the signal wire and the vibration resistance,
A plurality of sensors are required, and continuous detection is difficult due to the physical size of the sensors.

Further, in the above embodiment, the digital copying machine was explained as the image recording apparatus of the present invention, but the present invention can be naturally applied to the analog copying machine. However,
In the case of a digital copying machine, a sensor for reading a document, for example, CCD 16 can be used as a leading edge detector for detecting the leading edge position of the document set on the document table. In this case, the document leading edge sensor 4 is used.

[0032]

According to the first aspect of the present invention, there is provided a leading edge detector for detecting the leading edge position of the document set on the document table,
Since there is a position correction control means for starting the feeding of the transfer material by the registration rollers at the timing when the distance between the leading edge of the document detected by the leading edge detector and the standard leading edge position is calculated and corrected, the ADF or the manual setting Even if there are defects or variations, the same printed matter as the original can be obtained.

According to a second aspect of the present invention, a tip detector for detecting the tip position of the document set on the document table is provided, and the tip detector between the document tip detected by the tip detector and the standard tip position is provided. A timing that has position correction control means for starting the feeding of the transfer material by the registration rollers at the timing when the distance is calculated and corrected, and when the change means is selected, the position correction control means takes into account the changes made by the change means. The transfer material starts to be fed by the registration roller, so if the scaling function, binding margin adjustment function, image position shift function, etc. are selected by external input, select even when the original is misaligned and set. It is possible to perform the tip correction in consideration of the copy condition of the function that is performed.

According to the third aspect of the invention, since it is integrally supported by the scanner device for reading and scanning the original,
Prescanning is unnecessary, the image recording speed is high, and it is possible to continuously detect with one or a small number of sensors.

According to the structure of claim 4, the detector for detecting the leading edge position of the original document also serves as a sensor for reading the original image, so that a dedicated leading edge detector is unnecessary, prescanning is unnecessary, and the image recording speed is reduced. According to the configuration of claim 5, which can increase the speed, since the selection means for selecting whether or not the position correction control means controls is provided, the operator's request to cancel the tip correction can be answered.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a digital copying machine as an image recording apparatus according to the present invention.

FIG. 2 is an enlarged explanatory diagram showing an image reading unit in FIG.

FIG. 3 is a block diagram showing a control system related to position correction control means of the digital copying machine.

FIG. 4 is an explanatory diagram showing a method of detecting the leading edge of a document.

FIG. 5 is a flowchart showing a copy job related to the position correction control means of the digital copying machine.

FIG. 6 is an explanatory diagram showing another arrangement of the document leading edge detector.

[Explanation of symbols]

 1 Digital Copier 2 Contact Lath 4 Document Leading Edge Detector 6 Document Abutting Scale 7 Document 10 Image Reading Section 30 Image Forming Section 31 Photoreceptor

[Procedure amendment]

[Submission date] November 24, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

Furthermore, the present invention isThe position correction control hand
A selection means is provided to select whether or not to control the stage.
And is effective.

Claims (5)

[Claims] 1. An image reading unit for reading a document set on a platen with its front end aligned with a standard front end alignment position, and an image forming unit for forming an image of the read document on an image carrier. An image recording apparatus for recording an image formed by the image forming unit on a transfer material fed through a registration roller, comprising a leading edge detector for detecting a leading edge position of a document set on the document table, An image including position correction control means for starting the feeding of the transfer material by the registration roller at a timing when the distance between the leading edge of the document detected by the leading edge detector and the standard leading edge position is calculated and corrected. Recording device. 2. An image reading unit for reading a document set on a document table with its front end aligned with a standard front end alignment position, an image forming unit for forming an image of the read document on an image carrier, and an external input unit. Image recording for recording the image formed by the image forming unit on the transfer material fed through the registration roller. The apparatus is provided with a leading edge detector that detects a leading edge position of an original document set on the document table, and at a timing when the distance between the leading edge of the original document detected by the leading edge detector and the standard leading edge position is calculated and corrected. It has a position correction control means for starting the feeding of the transfer material by the registration roller, and when the changing means is selected, the position correction control means moves at the timing when the change contents of the changing means are added. The image recording apparatus characterized by starting the feeding of the transfer material by the registration rollers. 3. The image recording apparatus according to claim 1, wherein the detector for detecting the leading end position of the original document is integrally supported by a scanner device for reading and scanning the original document. 4. The image recording apparatus according to claim 1, wherein the detector for detecting the position of the leading edge of the original document also serves as a sensor for reading the image of the original document. 5. The image recording apparatus according to claim 1, further comprising selection means for selecting whether or not to control by the position correction control means.
The image recording apparatus according to claim 1.