JPH08234329A - Image forming device - Google Patents

Abstract

PURPOSE: To provide an image forming device in which a copy image can be formed in the center of a recording material regardless of the position of an original set on an original table. CONSTITUTION: This device has an original position detecting sensor 17 for detecting the position of an original supported by an original table, a reference display device 12 for showing the position of the original to be set on the original table, and a control panel 170 for giving instruction for switching between 'angle reference' and 'center reference', and the position for starting the read of the image of the document imaged on the light receiving surface of a CCD image sensor 24 can be optionally changed according to the size of original, copying magnification, the size of sheet, and the position of the original set on the original table. Thus, an undesired miscopy is prevented, and the copying cost can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image corresponding to image data by an electrostatic copying process and outputting the image on a sheet.

[0002]

2. Description of the Related Art An image forming apparatus using an electrostatic copying process, for example, an electrophotographic copying apparatus, stores a document holding unit for holding a document to be copied, and image information of the document held by the document holding unit. It has an image reading unit for taking out as light and dark information of light, an image forming unit for forming a copy image based on the image information read by the image reading unit, and then outputting it to a recording material.

The document holder has a document table made of a transparent material such as a glass plate, and a document scale indicating a position where a document to be copied is to be placed.

The image reading section illuminates a document set on a document table, and a CCD reading device for photoelectrically converting the reflected light from the document illuminated by the illumination lamp into an electric signal corresponding to image information. And an image forming lens device for making reflected light from the original document enter the light receiving surface of the CCD reading device in a stable state. It should be noted that the reflected light from the document toward the CCD reading device is generally
Original plate and CCD for the purpose of reducing the installation area of the device
After being bent several times by a plurality of mirrors arranged between the reading device and the reading device, it is guided to the light receiving surface of the CCD reading device.

The image forming unit includes a photoconductor that holds an electrostatic latent image corresponding to the image of the original read by the CCD reading device, a charging device that charges the photoconductor to a predetermined voltage, and a photoconductor charged by the charging device. Image exposure device for irradiating image information light for forming electrostatic latent image on body, developing device for developing by supplying developer to electrostatic latent image formed on photoconductor by image exposure device, developing device The transfer device is configured to transfer the developer image formed on the photoconductor to the recording material as the image output material, and the recording material feeding mechanism that feeds the recording material toward the transfer device. The developer image transferred onto the recording material via the transfer device is melted by being heated by the fixing device, and is fixed on the recording material by the pressure supplied from the fixing device.

By the way, as a position reference when setting a document on the document holding portion, an angle reference using two sides consisting of the leading edge of the document and one of the two sides in contact with the leading edge, the leading edge of the document and its edge are used. It is known that the central standard uses the central part of the.

In the corner-based electrophotographic copying apparatus, it is not necessary to consider the size of the original when setting the original in the original holder, and the original may always be set in the same position. However, when the size of the recording material required based on the size of the original document and the copy magnification does not match the size of the recording material actually supplied, the copied image obtained by copying is biased to the corner of the recording material. Known to be copied. Further, it is known that the recording material feeding mechanism is likely to be partially worn or easily change with time, and that the lens operation of the imaging lens device and the correction of the brightness according to the cosine fourth law are complicated.

On the other hand, in the central reference electrophotographic copying apparatus, when the size of the recording material required based on the size of the original document and the copy magnification does not match the size of the recording material actually supplied. Even if there is, the image of the original can be copied in the approximate center of the recording material within the range of the predetermined copy magnification.
On the other hand, it is known that when a document is set on the document table, the center of the document is likely to shift and an unwanted copy is likely to occur.

[0009]

By the way, at the present time, both the corner-based electrophotographic copying apparatus and the central-reference electrophotographic copying apparatus are mixed in the market. This causes a problem that an undesired copy is frequently generated when the user exchanges a copying apparatus having a different document reference position from the copying apparatus used before. Further, when the user has a plurality of copying machines and the copying machines have both the corner reference and the center reference, there are copies in which the center of the recording material and the center of the image obtained by copying do not match. There is a problem that tends to occur.

This not only increases the copying cost, but also causes a partial consumption of the developer, that is, a reduction in the image density in a specific area of the image obtained by copying. The purpose of this invention is
An object of the present invention is to provide an image forming apparatus that forms a copied image in the center of a recording material regardless of the position of a document set on a document table.

[0011]

SUMMARY OF THE INVENTION The present invention has been made based on the above-mentioned problems, and is a document supporting means for supporting a document, a first position of the document set on the document supporting means, and a first position of the document. An original position detecting means for detecting a second position different from the first position, an image reading means for reading an image of the original set on the original supporting means as light / dark information of light, and the image reading means for reading the image. Reading position control means for switching the position at which the reading of the image of the original is started between the first position and the second position detected by the original position detecting means, and the image read by the image reading means. A sheet feeding means for feeding a sheet for outputting the sheet, and an image of the document read by the image reading means, a position at which the document is set on the document supporting means, and the sheet. An image forming unit that forms an image at a predetermined position of the sheet fed through the feeding unit corresponding to the position to start the reading changed by the reading position control unit. .

According to the present invention, the original document supporting means for supporting the original document, the original document position instructing means for instructing the first and second positions where the original document should be set on the original document supporting means, and the original document An image reading unit that reads an image of the document set on the supporting unit as light and dark information of light, and a document position input unit that switches the instruction of the document position instructing unit between the first position and the second position. A sheet feeding means for feeding a sheet for outputting the image read by the image reading means, and a position for starting the reading of the image of the original by the image reading means by the document position instructing means. A read position control means for switching between the first position and the second position based on the read position and the position input by the document position input means; The image of the original read by the means is placed at the position where the original is set on the original support means and the predetermined position of the paper fed through the paper feeding means by the reading position control means. An image forming apparatus is provided that includes an image forming unit that forms an image corresponding to the changed position where the reading is started.

Further, according to the present invention, the document supporting means for supporting the document, the document position instructing means for instructing the first and second positions where the document is to be set on the document supporting means, and the document. Image reading means for reading the image of the document set on the supporting means as light and dark information of light;
Document position input means for switching the instruction of the document position instruction means between the first position and the second position;
Paper feeding means for feeding the paper for outputting the image read by the image reading means, magnification input means for inputting a magnification for outputting the image read by the image reading means, and the image reading means The position at which the reading of the image of the original is started by the first position input by the input unit based on the position instructed by the original position instructing unit and the position input by the original position input unit, and Switching between the second position, and
Reading position control means for changing the first position and the second position based on the magnification inputted by the magnification input means and the size of the paper fed by the paper feeding means; The reading position control is performed on the image of the document read by the image reading unit at a position where the document is set on the document supporting unit and a predetermined position of the sheet fed through the sheet feeding unit. And an image forming unit that forms an image corresponding to the reading start position changed by the unit.

Furthermore, according to the present invention, the document supporting means for supporting the document and the leading end of the document when the document is set on the document supporting means are in contact with each other. The first position indicating the position where the document is set so that the two sides of the document orthogonal to the leading end are located at the center of the document supporting means in the direction parallel to the leading end of the document, and the first position of the document. A second position indicating the position at which the document is set so that one of the two sides of the document orthogonal to the leading edge contacts one of the two sides of the document supporting means orthogonal to the leading edge of the document. An original position instructing means for instructing a position, an image reading means for reading an image of the original set on the original supporting means as light / dark information of light, and a position for starting the reading of the image of the original by the image reading means. , The reading position control means for switching between the first position and the second position, the paper feeding means for feeding the paper for outputting the image read by the image reading means, and the image reading The image of the original read by the means is placed at the position where the original is set on the original support means and the predetermined position of the paper fed through the paper feeding means by the reading position control means. An image forming apparatus is provided that includes an image forming unit that forms an image corresponding to the changed position where the reading is started.

Further, according to the present invention, the document supporting means for supporting the document and the leading end of the document when the document is set on the document supporting means are in contact with each other. The first position indicating the position where the document is set so that the two sides of the document orthogonal to the leading end are located at the center of the document supporting means in the direction parallel to the leading end of the document, and the first position of the document. A second position indicating the position at which the document is set so that one of the two sides of the document orthogonal to the leading edge contacts one of the two sides of the document supporting means orthogonal to the leading edge of the document. A document position designating unit for designating a position, an image reading unit for reading an image of the document set on the document supporting unit as light and dark information of light, and a sheet for outputting the image read by the image reading unit. The distance between the sheet feeding means for feeding and the first position and the second position is n [mm], the distance between the two sides of the document is P [mm], and the document is The amount of change in the position at which the image reading means starts reading the image of the original is Q [mm] depending on whether the original is set to the first position or the original is set to the second position. When, Q = n-P / 2
The reading position control means for switching the position at which the image reading means starts reading the image of the original document between the first position and the second position, and the reading position control means The image of the original is read by the reading position control means at the position where the original is set on the original supporting means and the predetermined position of the paper fed through the paper feeding means. An image forming apparatus having an image forming unit that forms an image corresponding to a start position is provided.

Furthermore, according to the present invention, the original is
Both the first position for supporting only the front end of the original document in contact with the predetermined position and the front end of the original document and one of the two sides of the original document in contact with the front end contact the predetermined position. The original supporting means for supporting the original at any one of the second and second positions, and the position at which the original is set on the original supporting means for the first and second positions corresponding to the first and second positions. Reference display means for displaying two reference positions; document position detection means for detecting whether the position of the document set on the document support means corresponds to the first position or the second position; Paper size setting means for setting the size of the paper for outputting the image of the original set on the original supporting means, and magnification input means for inputting a magnification for outputting the image of the original set on the original supporting means When, An image reading unit that reads an image of the document set on the document supporting unit as light / dark information of light with a predetermined width in a direction parallel to the leading end of the document and orthogonal to the leading end, and the reference display unit. Of the document, the detection result of the document position detection unit, the size of the sheet set by the sheet size setting, and the magnification input by the magnification input unit, respectively, based on each of the magnifications input by the magnification input unit. An image forming apparatus is provided that includes: a reading position control unit that changes a position at which reading of an image in a direction parallel to the leading edge of the original is started.

[0017]

According to the present invention, the position for starting the reading for reading the image of the document supported by the document supporting means is
The reading position control means switches between the first position and the second position detected by the document position detection means. Therefore, even when the position where the document is set on the document supporting unit is changed, the image of the document can be provided on the paper in a state that is substantially the same as the state where the document is set on the document supporting unit.

Further, according to the present invention, the position where the reading of the image of the original document supported by the original document supporting means is started is the position designated by the original document position indicating means and the position input by the original document position inputting means. Based on the above, the reading position control means is used to switch between the first position and the second position. Therefore, even when the position where the document is set on the document support unit is changed, the state is almost the same as the state where the document is set on the document support unit,
The image of the original can be provided on paper.

Further, according to the present invention, the position where the image reading means starts reading the image of the original is based on the position indicated by the original position indicating means and the position input by the original position input means. The switching between the first position and the second position is performed, and the first position and the second position are set based on the magnification input by the magnification input means and the size of the paper fed by the paper feeding means. By the reading position control means for changing the position, the reading changed by the reading position control means is performed at the position where the original is set on the original supporting means and the predetermined position of the paper fed through the paper feeding means. An image is formed corresponding to the start position. Therefore, even when the position where the document is set on the document supporting unit is changed, the image of the document can be provided on the paper in a state that is substantially the same as the state where the document is set on the document supporting unit. Further, according to the present invention, the document position indicating means is such that the leading edge of the document comes into contact when the document is set, and two sides of the document orthogonal to the leading edge of the document are the document supporting means. The first position indicating the position where the document is set so as to be positioned at the center in the direction parallel to the leading end of the document, and one of the two sides of the document orthogonal to the leading end of the document is the leading end of the document of the document support means. Since the second position indicating the position where the document is set is in contact with one of the two sides orthogonal to, the image of the document read by the image reading unit is transferred to the document supporting unit. It is possible to form an image at the set position and a predetermined position of the sheet fed through the sheet feeding means, corresponding to the reading start position changed by the reading position control means. As a result, even when the position where the document is set on the document supporting unit is changed, the image of the document can be provided on the paper in a state that is substantially the same as the state where the document is set on the document supporting unit. Furthermore, according to the present invention, the reading position control means allows the distance between the first position and the second position on the document supporting means to be n [mm] and the distance between the two sides of the document to be P [mm]. ], And the change amount of the position at which the image reading means starts reading the image of the document depending on whether the document is set at the first position or the second position is Q [mm]. Q =
At n−P / 2, the position at which the image reading unit starts reading the image of the document is switched between the first position and the second position. The image is displayed at a position where the document is set on the document supporting unit and a predetermined position of the sheet fed through the sheet feeding unit, in correspondence with the position where the reading is started, which is changed by the reading position control unit. Can be formed. As a result, even when the position where the document is set on the document supporting unit is changed, the image of the document can be provided on the paper in a state that is substantially the same as the state where the document is set on the document supporting unit.

[0020]

Embodiments of the present invention will be described in detail below with reference to the drawings. As shown in FIG. 2, the image forming apparatus, that is, the electrophotographic digital copying apparatus 2 has an image reading unit 4 that functions as a reading unit and an image forming unit 6 that functions as an image forming unit. The image reading unit 4
The upper part of the image reading unit 4 is formed so as to be openable / closable with respect to a later-described document table of the image reading section 4, and the objects to be read, that is, the documents D are fed one by one toward the document table and placed on the document table. An automatic document feeder (hereinafter, referred to as ADF) 8 that functions as a document retainer for bringing the document D into close contact with the document table is set.

The image reading unit 4 is arranged on one side of the document table 11 and a document table 11 made of transparent glass on which the document D is set, facing the closed ADF 8 at the upper part thereof. 11 has a reference display device 12 indicating the position where the document D is to be set. A control panel, which will be described later with reference to FIG. 3, is arranged near the document table 11 surrounding the document table 11.

Below the document table 11, the image reading unit 4 is provided with an exposure lamp 13 for illuminating the document D placed on the document table 11, and for converging light from the exposure lamp 13 on the document D. The auxiliary reflection plate 14 and the first mirror 15 that bends the reflected light from the document D to the left in the drawing are arranged. Exposure lamp 13, auxiliary reflector 14 and first
The mirror 15 is fixed to the first carriage 16,
The first carriage 16 is arranged so as to be movable in parallel with the document table 11 with the movement of the first carriage 16. The driving force of a pulse motor (not shown) is transmitted to the first carriage 16 via a toothed belt (not shown), and the first carriage 16 is moved in parallel along the document table 11.

At a predetermined position below the manuscript table 11 and in the vicinity where the reference display device 12 and the manuscript table 11 are in contact with each other, the manuscript D is located on the manuscript table 11 which will be described later with reference to FIG.
A document position detection sensor 17 for detecting whether or not is set is arranged.

In the left side of the document table 11 in the direction in which the reflected light reflected by the first mirror 15 is guided, it is parallel to the document table 11 via a drive mechanism (not shown) such as a toothed belt and a DC motor. A second carriage 20 is arranged so as to be movable.

The first carriage 15 is attached to the second carriage 20.
The second mirror 21 that bends the reflected light from the document D guided by and downward and the third mirror 22 that bends the reflected light to the right in the drawing are arranged at right angles to each other. Second carriage 2
0 is driven by the first carriage 16 by a toothed belt (not shown) for driving the first carriage 16 and is moved in parallel along the document table 11 at a speed of ½ with respect to the first carriage 16. It

The reflected light from the second carriage 20 is imaged at a predetermined magnification in the plane below the first carriage 16 and including the optical axis of the light reflected by the second carriage 20. An image forming lens 23 and a CCD image sensor 24 that converts the reflected light, which is focused by the image forming lens 23, into an electric signal, that is, image data are arranged.

The image forming section 6 is a photoconductive drum 3 as an image carrier rotatably positioned in the center of the copying apparatus 2.
Has 0. The photoconductor drum 30 is rotated at a predetermined rotation speed by a motor (not shown).

At a predetermined position around the photosensitive drum 30, a charger 31 for charging the surface of the drum to a predetermined electric charge, and image data supplied from an image processing unit described later, that is, image information to be image-formed, are provided. A laser beam generated from a laser diode (not shown) is deflected in the axial direction of the photosensitive drum 30 by a polygon mirror 32a as a deflecting device, and at the same time, the first and second folding mirrors 32b and 32c and the fθ lens 3 are provided.
A laser exposure device 32 that forms an electrostatic latent image on the surface of the photoconductor drum 30 by exposing the surface of the photoconductor drum 30 through 2d, and the surface of the photoconductor drum 30 is exposed by the laser exposure device 32. A developing device 33 having a developing roller 33a for supplying a toner as a developer to the formed electrostatic latent image to develop the electrostatic latent image at a desired image density, and a transfer material, that is, a copy sheet P fed from a sheet cassette described later.
The toner image formed on the photosensitive drum 30 is transferred onto the photosensitive drum 30 and the paper P on which the toner image is transferred is transferred onto the photosensitive drum 30.
From the surface of the photoconductor drum 30, a peeling claw 35 for peeling the copy sheet P from the surface of the photoconductor drum 30, a cleaning device 36 for cleaning the toner remaining on the surface of the photoconductor drum 30, and the photoconductor drum. A static eliminator 37 for eliminating static potentials remaining on the surface of 30 is arranged in order.

At the bottom of the copying machine 2 located below the photosensitive drum 30, a multi-stage paper feeding device as a paper feeding means is detachably mounted in a plurality of upper and lower stages from the front side of the copying machine 2.
40 (hereinafter referred to as PFP) is arranged integrally with the copying apparatus 2.

The PFP 40 includes an upper cassette 41, a middle cassette 42, and a lower cassette 43 for accommodating a plurality of types of copy sheets P of various sizes. Each of the cassettes 41, 42 and 43 is, for example, in the longitudinal direction. The A4 size copy sheet, the B4 size copy sheet and the A3 size copy sheet placed so as to be conveyed along are each formed to be able to store about 500 sheets.

Pickup rollers 44a, 44b and 44c are provided at predetermined positions of the upper cassette 41, the middle cassette 42 and the lower cassette 43 to take out the sheets P one by one from the respective cassettes 41, 42 and 43.

Each pickup roller 44a, 4
4b and 44c for each cassette 41, 42 and 4
A conveyance roller 45 for separating the sheets P one by one is provided at a position where the leading edge of the sheet P taken out from the sheet 3 is passed.
a, 45b and 45c, and separation rollers 46a, 46b and 46 that are integrally arranged with the respective conveying rollers.
c is arranged. The separation rollers 46a, 46b and 46c are arranged such that their axes are parallel to the mutually combined transport rollers and are in contact with each other at a predetermined pressure, and rotate in a direction opposite to the rotation direction of the transport rollers. By doing so, only the uppermost one sheet of the paper P taken out from each cassette is delivered to the transport path described later.

To the right of the PFP 40 in the figure, there are three sheets of paper P of a size that is frequently used, for example, A4 size paper P.
A large-capacity feeder (hereinafter referred to as LCF) 47 that can store about 000 sheets is provided. LCF47
The paper P accommodated in the LDF 47 is
A pickup roller 48 is arranged to take out the sheets one by one. A separating mechanism 49 including a pair of upper and lower conveying rollers 49a and a separating roller 49b is arranged between the pickup roller 48 and the photosensitive drum 30. The separating mechanism 49 rotates the separating roller 49b in a direction opposite to the direction in which the conveying roller 49a is rotated, so that only the uppermost one sheet of the paper P taken out from the LDF 47 by the pickup roller 48 is conveyed as described later. Send to the road.

Above the LCF 47, each cassette 41,
Copy paper P independently of 42, 43 and LCF 47
A manual feed feeder 50 capable of feeding paper is formed. Between the manual feed feeder 50 and the photoconductor drum 30, a manual feed pickup roller 51 for taking in the paper P inserted in the manual feed feeder 50, a manual feed guide 52 for guiding the paper P taken in by the pickup roller 51,
Further, a conveyance roller 53 that conveys the sheet P guided toward the photosensitive drum 30 via the manual feed guide 52 is provided.

Respective cassettes 41, 42 and 43
In addition, between the LCF 47 and the photoconductor drum 30, the conveyance path 5 for guiding the paper P from the cassettes 41, 42 and 43 and the LCF 47 toward the photoconductor drum 30.
4 are formed. The conveyance path 54 further extends to the outside of the copying apparatus 2 via a transfer area defined between the photosensitive drum 30 and the transfer / separation charger 33. Further, in the transport path 54, the paper P fed from any of the cassettes, the LCF, or the manual feed guide is used.
A plurality of transport rollers 55 for transporting the sheet toward the photoconductor drum 30 are provided.

In the vicinity of the photosensitive drum 30 on the conveying path 54 and on the upstream side, the copy sheet P guided along the conveying path 54.
Of the toner image on the photoconductor drum 30 and the tip of the copy paper P are aligned, and the copy paper P is transferred to the transfer area at the same speed as the moving speed of the outer peripheral surface of the photoconductor drum 30. An aligning roller 56 for feeding paper is arranged. Further, in front of the aligning roller 56, that is, on the side of the transport roller 55, the aligning roller 56
An aligning sensor 56a is provided for detecting the arrival of the copy sheet P to the sheet.

A conveyor belt 57 for conveying the paper P is incorporated in the direction in which the paper P passing through the transfer area advances. At the position where the paper P is conveyed by the conveyor belt 57 and the heat is less likely to be applied to the photoconductor drum 30, a pair of heat rollers whose roller surfaces are in pressure contact with each other is included and the toner image is transferred to the paper. A fixing device 58 for fixing the toner image on the paper P by heating the toner image and melting the toner image to press the toner image and the paper P is provided.

On the side wall of the copying machine 2 facing the fixing device 58, the paper P on which the toner image is fixed by the fixing device 58.
A discharge tray 59 for discharging is disposed. A discharge switching unit 60 is disposed between the fixing device 58 and the discharge tray 59 to guide the copy paper P, on which the toner image is fixed by the fixing device 58, to either the paper reversing unit or the discharge tray 59 described later. There is.

The discharge switching unit 60 is arranged between the first and second discharge rollers 61 and 62 for propelling the sheet P that has passed through the fixing device 58, and between the first and second discharge rollers 61 and 62. A distribution gate 63 is provided for selectively distributing the copy paper P, which has passed through the fixing device 58, to either the discharge tray 59 or a paper reversing unit described later.

The reversing mechanism 64 includes a temporary stacking unit 65 for temporarily stacking the copy paper P that has already passed through the transfer area and the fixing device 58, and the copy paper P that has passed through the fixing device 58.
A reversing path 66 for reversing the front and back of the sheet to the temporary stacking section 65, a pickup roller 67 for taking out the copy sheets P stacked in the temporary stacking section one by one, and the aligning rollers for the sheets P stored in the temporary stacking section 65 again. It has a reversing conveyance path 68 that guides the sheet 56, and a paper feed roller 69 that feeds the sheet P guided by the reversal conveyance path 68 toward the aligning roller 56.

The ADF 8 has a cover 71, and the cover 7
The rear edge of the copying machine 1 is attached to the rear edge of the upper surface of the copying apparatus 2 via a hinge device (not shown).
By rotating and displacing the entire DF 8, as described above, it is formed so as to be openable and closable with respect to the document table 11 of the image reading section 4.

A document feeding table 72 for holding a plurality of documents D is provided on the upper surface of the cover 71 slightly to the left. The documents D set on the document feed table 72 are sequentially taken out one by one on the left side of the document feed table 72 in the figure, that is, one end side of the ADF 8, and the document table 11 of the image reading unit 4 is read from the left end side in the figure. A pickup roller 73 for supplying to one end side of is arranged. An empty sensor 7 as a document detection sensor for detecting whether or not the document D is set on the document feed table 72 at a predetermined position of the document feed table 72.
3 are provided. A document width detection sensor (not shown) that functions similarly to the document position detection sensor 17 that detects the position where the document D is set on the document table 11 may be arranged on the document feed table 72.

In the original pick-up direction of the pickup roller 73, the paper feed roller 74 for sending the original D taken out by the pickup roller 73 toward the original table 11 and the leading end of the original D fed by the paper feed roller 74 are arranged. An aligning roller 75 for aligning is arranged. The document D is placed between the aligning roller 75 and the paper feeding roller 74.
An aligning sensor 75a for detecting the arrival of the aligning roller 75 on the aligning roller 75 is arranged.

Inside the cover 71, at a position facing the document table 11 of the image reading section 4 in a state where the ADF 8 is closed, a size that covers almost the entire document table 11 is provided, and a pickup roller is provided. A conveyance belt 76 is arranged to convey the document D conveyed from the document feed table 72 via the document feed roller 74 and the aligning roller 73 to a predetermined position on the document table 11. The conveyor belt 76 is stretched around belt rollers 77 arranged in a pair in the left and right in the figure, and is rotated by a belt drive mechanism (not shown) toward both the right side in the figure and the left side in the figure.

A conveyor belt 76 is provided on the right side of the ADF 8.
Thus, the reversing roller 78 that sends the document D moved from the left side to the right side in the drawing toward the outside of the cover 71, the pinch roller 79 that presses the document D against the reversing roller 78, and the reversing roller 78 and the pinch roller 79 convey the document D. Document D
Flapper 8 which switches between returning to the transport belt 76 again or discharging to a predetermined discharge position, that is, the cover 71.
0, when the flapper 80 is switched to the discharge side, a discharge roller 81 that discharges the document D conveyed by the reversing roller 78, and a jam sensor 82 that detects a jam of the document near the reversing roller 78. Are arranged.

FIG. 1 is a block diagram schematically showing a control mechanism of the electrophotographic digital copying apparatus 2 shown in FIG. The control mechanism of the electrophotographic digital copying apparatus 2 includes a control panel 110, which controls a reference panel 12 which indicates a reference position when a document is set on a document table 11 and a control panel 110 which will be described later with reference to FIG.
Scanner unit 120 for reading the image information of the printer unit, and printer unit 1 for forming an image on the paper P based on the input image information.
30, a scanner unit 120 and a memory editing unit 140 that processes image data supplied from an external device described later, such as a facsimile device, a hard disk device, or a known local area network (hereinafter, LA
(Shown as N), a system unit 150 that manages the input of image data from a computer and a word processor, etc., and a control panel unit 110, a scanner unit 120, a printer unit 130, a memory editing unit 140, and a system unit 150, respectively. The main control unit 160 controls the transmission and reception of signals between the two.

The control panel section 110 includes a control panel CPU 111 and a control panel CPU
Read-only memory (hereinafter referred to as R
112 and random access memory
(Hereinafter, referred to as RAM) 113.

The control panel CPU 111 uses the RO
Based on the data stored in the M112 and the RAM 113, detection of input by various switches and a touch panel arranged on the control panel and the reference display device 12 described later with reference to FIG. 3, display on the touch panel, and It controls the turning on and off of the LED.

The scanner unit 120 includes the scanner CPU 12
1 and a ROM 122 connected to the scanner CPU 121
And RAM 123, ROM 122 and RAM
By the control of the scanner CPU 121 based on the control data stored in 123, the CCD of the image reading unit 4
A mechanism for operating the image sensor 24 to capture the image of the document D as light and dark information of light and energizing a DC motor or the like (not shown) for moving the first carriage 16 and the second carriage 20 at a predetermined speed. A predetermined drive signal is output to the control unit 124.

The scanner section 120 also passes through the A / D conversion circuit 125 and the A / D conversion circuit 125, which convert the analog image data output from the CCD image sensor 24 into a digital signal by a known A / D conversion. The shading correction circuit 126 that removes the influence of the individual error of the output of the CCD image sensor 24 and the nonuniformity of the light amount from the illumination lamp 13 from the image signal converted into the digital signal, and the CCD image sensor 24 read the shading correction circuit 126. It has a line memory 127 for supplying the image information of the document D to the memory editing unit 140 connected at the subsequent stage at a predetermined timing, and has the ROM 122 and RA.
Under the control of the scanner CPU 121 based on the data of M123, the image information of the document D read by the CCD image sensor 24 is converted into an electric signal, which is then binarized at a predetermined threshold level and connected to the memory editing unit 140 at the subsequent stage. To the page memory described later.

The scanner CPU 121 has an ADF
8 is also connected. The ADF 8 is the scanner CPU 1 based on the control by the main control unit 160 described later.
The document D is fed under the control of 21. Also, the scanner C
When editing data is input to the PU 121 from a coordinate input device (not shown), predetermined control data is output to the page memory of the memory editing unit 140, which will be described later, and image data used for image formation is held. An editor 128 for controlling the size of the memory area is also connected.

The printer unit 130 includes the printer CPU 13
1 and a ROM 132 connected to the printer CPU 131
An image is formed on the paper P based on the image information read via the image reading unit 4 and the image data supplied from an external device described later, including the RAM 133.

In the printer CPU 131, the photosensitive drum 30, the developing roller 33a of the developing device 33, the aligning roller, the conveyor belt, the fixing device, the reversing mechanism, and the cassettes 41, 42 and 43 of the multi-stage paper feeding device 40, and A motor drive circuit 134 that drives a motor (not shown) that rotates such as a pickup roller and a conveyance roller and a separation roller arranged in each LDF 47, a document position detection sensor 17 that detects the position of the document D set on the document table 11, and A paper empty switch (not shown) arranged in each of the cassettes 41, 42 and 43 and the LDF 47, the conveyance path 54 and the reversing mechanism 6
4, a lever switch (not shown) that detects jamming of the paper P, an input circuit 135 that is used for inputting signals output from switches and sensors such as the aligning sensor 56a, and For example, a mechanism control unit 136 for urging a sorting gate 63 of the discharge switching unit 60 or a solenoid (not shown) included in the cleaning device 35 is connected.

The printer CPU 131 also has a temperature control circuit 137 for controlling the temperature of the fixing device 58, a voltage supply circuit 138 for applying a predetermined voltage to the charging charger, the developing device, the transfer / peel charger, and the like, and a laser exposure device. A laser drive circuit 139 for intensity-modulating the light intensity of a laser beam emitted from a laser diode (not shown) 32 corresponding to image data supplied from a page memory, which will be described later, is connected to the ROM 132 and the RAM.
An image is formed on the paper P under the control of the printer CPU 131 based on the data 133.

The memory editing unit 140 is a memory control CPU.
141 including a main CPU described later of the main control unit 160 and a system C described later of the system unit 150.
Image data supplied from the scanner unit 120 or an external device according to an instruction from both the PU and the printer unit 1
After being converted into bitmap data used for intensity modulation of the laser beam emitted from the laser diode of the laser exposure device 32 of 30, the page memory shown in the subsequent stage is temporarily stored.

In the memory control CPU 141, the image data supplied from the external device via the system unit 150 and the image data read by the scanner unit 120 and then specified by the image processing unit described later in the main control unit 160 are specified. An image editing unit 142 that edits the image data of the document D converted to the format, a compression / decompression unit 143 that compresses or decompresses the input image data, and an enlargement / reduction or rotation of the input image data. Reduction / rotation unit 14
4, a page memory 145 that stores image data processed through the image editing unit 142, the compression / expansion unit 143, and the enlargement / reduction / rotation unit 144 page by page, an address control unit 146 that manages memory addresses, and a memory A memory management control unit 147 for managing the data of the above, and an interrupt control unit 148 for giving instructions for processing such as compression / expansion and enlargement / reduction / rotation to the image data taken in by the image editing unit 142. Are connected.

The system section 150 includes a system CPU 151 for controlling the capturing of image data supplied from other than the scanner section 120, and a facsimile apparatus 152 as an external apparatus connected to the system CPU 151, a hard disk apparatus 153, a computer (not shown) and A LAN 154 to which a word processor or the like is connected, and a printer controller 155 for converting image data supplied via the facsimile 152, the hard disk device 153, and the LAN 154 from code data into image data in a format processable by the copying apparatus 2, respectively. By controlling, the image editing unit 142 of the memory editing unit 140 is made to input the image data.

The main control section 160 operates in the copying apparatus 2, that is, the CPUs 121 and 13 of the control panel section 110, the scanner section 120, the printer section 130, the memory editing section 140 and the system section 150, respectively.
Main CPU 161 controlling 1, 141 and 151
have.

The main CPU 161 has a ROM 162 in which initial data for operating the copying apparatus 2 is stored, and the control panel section 110, the scanner section 120, and the printer section 130 under the control of the CPUs 121, 131, 141, and 151. , Memory editing unit 14
0 and the RAM 163 holding various data input from the system unit 150, respectively.

The main CPU 161 also holds a printer font R which holds a printer font used to store the code data input via the system section 150 in the page memory 145 of the memory editing section 140.
The OM 164 displays an image corresponding to the code data input via the system unit 150 on an editing display device (not shown), and a predetermined image is displayed on a liquid crystal display / input panel of a control panel described later with reference to FIG. Display font ROM 165 holding a display font for displaying the image of the image, the scanner unit 12
The line memory 12 of the scanner unit 120 is used for specifying the destination of the image data read by 0, switching the image data to be supplied to the printer unit 130, and the like.
7 and the page memory 145 of the memory editing unit 140 and between the page memory 145 and the laser exposure device 32, the data switching / buffer memory 166 that functions as a buffer memory, and
An image processing unit 167 for masking or trimming the input image data is connected.

FIG. 3 is a schematic plan view showing an example of a control panel incorporated in the copying machine shown in FIG. As shown in FIG. 3, the control panel 170 has a plurality of input keys capable of inputting a destination name or the like by means of katakana as a copy condition, an image editing operation, or a facsimile device communication function operation, and a facsimile transmission destination identification. A touch panel 171, which is used as a speed dial key used in a speed dial mode in which a facsimile number can be preset, is formed integrally with the touch panel 171, and displays various operating areas of the copying apparatus 2 and the ADF 8 or various key areas forming the touch panel. Liquid crystal display / input device (hereinafter referred to as LCD panel) 172, and LED panel 173 for displaying the status of the copying apparatus 2, for example, paper out or paper jam.
have. In the LCD panel 172, various display patterns and input key areas corresponding to the display data stored in the ROM 162 of the main control unit 160, for example, the reference position when the document D is set on the document table 11 is changed. A pattern or the like indicating possible input of the reference position selection mode is displayed.

The control panel 170 also includes, for example, numeral keys 181 used for inputting the number of copies, a clear key 182 for clearing the number of copies, ie, returning to "1", and a print key for starting copying. 183, an all clear key 184 for setting the copy condition to an initial state, a magnification setting key 185 for setting the copy magnification, and a reference position change for operating the reference display device 12 at either the center reference or the corner reference. Standard change key 186, copy mode setting key 187 for setting copy mode such as double-sided / double-sided, single-sided / double-sided, paper size for printing image data, that is, paper containing paper of different sizes A cassette that outputs a switching signal corresponding to an instruction for switching the cassette and the LCF as a supply source. Tsu DOO switching key 188 and, such as density adjustment key 189 for setting the image of the output image formed on a sheet to a predetermined concentration is disposed.

FIG. 4 is a schematic view showing an example of a document position detecting sensor incorporated in the copying machine shown in FIG. FIG.
As shown in FIG. 3, the document position detection sensor 17 is located below the document table 11 of the copying apparatus 2 and is a corner of two sides surrounded by the document table 11 and the reference display device 12, that is, the document table 1.
The document D is arranged at a position corresponding to the corner of the area on which the document D can be set.

The document position detecting sensor 17 is arranged, for example, so that the reflected light is incident only when the LED element 17a for emitting light of a predetermined wavelength and the light emitted from the LED element 17a are reflected by the document D. Photo detector 1
When the reflected light having a predetermined light intensity is incident on the photodetector 17b, the original detection voltage of a predetermined magnitude is output to the input circuit 135 of the printer unit 130. Even when the document D is set on the document table 11 with the center reference, if the size of the document D is close to the upper limit of the document size that can be copied by the copying apparatus 2, the reference display device 12 is used. Since the gap S between the end of the document table 11 and the end of the document D that come into contact with is small, the document position detection sensor 17 is arranged close to the end of the document table 11.

FIG. 5 is a schematic plan view showing an example of a reference display device incorporated in the copying machine shown in FIG. The reference display device 12 includes a front end portion 11a on the left side of the document table 11 in the figure.
It is arranged from above the document table 11 so as to hold down.

The reference display device 12 is the display device main body 200.
And a plurality of light emitters 201, 202 and 211 to 219 incorporated in the display device main body 200. In addition, on the upper surface of the display device main body 200, each light-emitting body 2
Reference marks 221 and 222 and size marks 231 to 239 which are illuminated independently when 01, 202 and 211 to 219 are lit are arranged.

The light emitters 201 and 202 are respectively
The reference marks 221 and 222 for indicating the reference position when the document D is set on the document table 11 are illuminated, and the reference change key 1 of the control panel 170 is illuminated.
Each time 86 is pressed, the light emitter 201 indicating the corner reference and the light emitter 202 indicating the center reference are alternately turned on. As a result, each time the reference change key 186 is pressed, the reference marks 221 and 222 are displayed alternately.

The light emitters 211 to 219 are respectively
The size marks 231 to 239 are illuminated, and the light emitters 211 to 213 are the reference change keys 1 respectively.
When the corner reference is input via 86, the size reference marks 221 and the size marks 231 to 233 arranged at the positions corresponding to the document sizes of “A4”, “B4”, and “A3” are also displayed. Display it. In addition, the luminous body 2
14 to 219 respectively indicate the center reference mark 2 when the center reference is input via the reference change key 186.
22, the size marks 234 to 239 arranged at positions corresponding to two sides of the originals “A4”, “B4” and “A3” are displayed.

Next, the reference position of the original and the operation of the copying apparatus when the image of the original is copied by the copying apparatus will be described. FIG. 6 shows the difference between the corner reference and the center reference when the document D is set on the document table 11.

As shown in FIG. 6, when the "A3" size document D is set on the document table 11 based on the corner,
The leading edge of the document D is in contact with the reference line 12a of the reference display device 12, and one side of the two sides in contact with the leading edge of the document D is arranged to be orthogonal to the reference line 12a. Is struck by. As a result, the document D is set on the document table 11 in the upper side of the drawing and to the left of the drawing with the reference mark 221 shown in FIG. 5 and one of the four corners of the document D aligned.

On the other hand, when the "A3" size original D is set on the original table 11 with the central reference, the original D
The leading end of the document D is brought into contact with the reference line 12a of the reference display device 12 with the center of the leading end of the document D aligned with the reference mark 222 shown in FIG. That is, the “A3” size document D is set between the size marks 238 and 239 shown in FIG. 5 of the reference display device 12.

Here, the difference in the reading position of the image of the document D between the corner reference and the center reference of the "A3" size document D, that is, the position of the side regulating member 11a of the document table 11, that is, the document D at the corner reference. Q _A3 [mm] between the position of the side Da of the document D and the position of the side Da ′ of the document D at the center reference.
Is obtained, the difference between the reference positions of the corner reference and the center reference is n [mm], and the width of the “A3” size document D is P _A3 [m
m], Q _A3 = n − P _A3 / 2.

Similarly, for the originals D of all sizes, the difference Q [mm] in the reading position of the image of the original D between the corner reference and the center reference is calculated. When the difference between the reference positions of n is [mm], and the width of the corresponding document D is P [mm], respectively, Q = n-P / 2.

Next, the relationship between the reading position of the image of the original D and the writing position of the image formed on the paper P will be described with reference to FIGS. Generally, copying machine 2
In the case of reading the image of the document D set on the document table 11, the image area included in the document D is in the first direction, that is, the main scanning direction and the main scanning direction, which coincides with the longitudinal direction of the CCD image sensor 24. For the sake of convenience, it is divided into a second direction orthogonal to the sub-scanning direction, the image information is read with a predetermined width in the sub-scanning direction with respect to the main scanning direction, and then the sub-scanning is obtained by reading once in the sub-scanning direction. The reading position is shifted by an amount corresponding to the width in the direction, and the reading is repeated according to the length method of the original D to read the original D.
The method of photoelectrically converting all the image information of is used.

In many cases, the direction in which the axis of the illumination lamp 13 of the first carriage 16 and the axis of the photosensitive drum 30 extend, that is, the direction in which the reference display device 12 extends and the main scanning direction coincide with each other. The direction in which the carriage 16 is moved and the direction in which the m symbol 30 is rotated, that is, the direction orthogonal to the reference line 12a of the reference display device 12, is aligned with the sub-scanning direction.

As a result, the reflected light from the region of the predetermined width of the document D illuminated by the illumination lamp 17 of the first carriage 16 is sequentially reflected by the first mirror 15, the second mirror 21 and the third mirror 22. An image is formed on the light receiving surface of the CCD image sensor 24 by the image forming lens 23, and the first image information in the main scanning direction having a predetermined width in the sub scanning direction is photoelectrically converted. Subsequently, the first carriage 16 is moved by a predetermined width in the sub-scanning direction, so that the second image information in the main scanning direction having a predetermined width in the sub-scanning direction is photoelectrically converted. Thereafter, as the first carriage 16 is moved, the third, fourth, fifth, ... Image information in the main scanning direction having a predetermined width in the sub-scanning direction is photoelectrically converted in order by the CCD image sensor 24. Then, the image information of the document D is read as the light and dark information by illuminating the illumination lamp 17. The width of the image area in the sub-scanning direction of the document D photoelectrically converted by one reading by the CCD image sensor 24 is the reading resolution peculiar to the CCD image sensor 24 or the CCD image sensor 2.
According to the resolution corresponding to the input from the control panel with the upper limit of the reading resolution peculiar to 4,
It is regulated to 1/400 dots per inch (hereinafter referred to as [dpi]) or 1/200 [dpi].

By the way, as shown in FIG. 7A, when the document D is set on a corner basis, the reading start position when the image information of the document D is read through the CCD image sensor 24 is As shown in FIG. 7B, when the original D is viewed from the front side, that is, the image information side of the original D, regardless of the size of the original D, that is, the original size, the CCD
It is aligned with the left end of the image reading position of the image sensor 24.

On the other hand, when the document D is set with the center reference as shown in FIG. 8A, the reading start when the image information of the document D is read through the CCD image sensor 24 As shown in FIG. 8B, the position coincides with the size of the document D, that is, the reading start position peculiar to the document size.

On the other hand, the laser exposure device 32 of the copying apparatus 2
Is PFP40, LCF47 and manual feeder 50
A laser beam corresponding to the image data to be image-formed is applied to the write start position obtained from the relative position between the paper P and the photoconductor drum 30 fed toward the photoconductor drum 30 from each of the above.

By the way, the paper P fed toward the photoconductor drum 30 is subjected to a partial abrasion or fixing device of the paper carrying mechanism represented by various rollers and a carrying belt for carrying the paper P. In order to prevent "wrinkles" that may occur on the passed paper P, the center of the main scanning direction and the center of the paper P in the direction orthogonal to the direction in which the paper P is conveyed match regardless of the paper size. Be sent to do so.

Therefore, as shown in FIG. 9, the writing position of the laser beam emitted from the laser exposure device 32 toward the photosensitive drum 30 depends on the size of the paper P on which the image is formed. It must be matched to a pre-specified unique writing. Since the size of the paper P is defined according to the size of the document D and the copy magnification input from the control panel 170,
It goes without saying that the writing position of the laser beam from the laser exposure device 32 does not depend on the size of the document D.

That is, the writing start position of the laser beam emitted from the laser exposure device 32 toward the photoconductor drum 30, that is, the writing timing, is either "corner reference" or "center reference" of the document D on the document table 11. Even if it is set by the method, the size of the paper P is "A
3 "is used as a reference and the paper P that is actually used
The difference in size of n (n is the size of the paper) is x [m
m] and the delay of the writing start position with respect to the paper Pn as y [mm], when the size of the paper Pn is “A4”, y _A4 = x _A4 / 2, and similarly, When the size of Pn is “B4”, a writing position specific to the size of the paper P is given as shown by y _B4 = x _B4 / 2.

Next, the copying operation of the image of the original by the copying apparatus shown in FIGS. 1 and 2 will be described. The copying machine 2 is warmed up and initialized in accordance with a control program stored in the ROM 162 when a main switch (not shown) is turned on. Further, the scanner unit 120 under the control of the main CPU 161.
AD (not shown) according to an instruction from the scanner CPU 121 of
The ADF 8 is also initialized according to the control program stored in the FROM. The ADF8 is
It is assumed that the document D is fed to the document table 11 based on the "center reference".

When the print key 183 of the control panel 170 is turned on after the document D to be copied is set on the document tray 72 of the ADF 8, an AD not shown that the empty sensor (not shown) of the ADF 8 is turned on.
Checked by FCPU. When the empty sensor detects that the document D is set on the document tray 72, the pickup roller 73 is driven in accordance with the supply of the drive current from the motor drive circuit (not shown) to the sheet feeding motor (not shown), and the document is moved. The lowermost original document set on the tray 72 is guided to the paper feed roller 74. The document D guided by the paper feed roller 74 is further conveyed toward the aligning roller 75.

Subsequently, when the leading edge of the document D passes through the aligning sensor 75a, the clutch (not shown) is turned on via the ADF mechanism controller (not shown), and the aligning roller 75 is stopped. As a result, the document D taken out from the document tray 72 is temporarily stopped by the pickup roller 73, and the inclination of the document D with respect to the document transport direction is corrected. After that, the belt roller 77 is rotated in the first direction, that is, the document feeding direction by the drive motor (not shown) to rotate the conveyor belt 76, and then the clutch (not shown) is turned off at a predetermined timing and the aligning roller 75 is removed. The document D is fed to the conveyor belt 76. After that, the conveyance belt 76 is rotated by the conveyance motor for a predetermined time, so that the original D
Are conveyed onto the document table 11 of the copying apparatus 2. The rear end of the document D of the transport belt 76 is aligned with the aligning sensor 75.
After passing through a, it is stopped for a fixed time, that is, after a lapse of a time predetermined by the distance between the aligning sensor 75a and the reference indicating device 12, and rotation by inertia is prevented by a brake (not shown).

At the time when the leading edge of the document D is detected by the aligning sensor 75a, the scanner CPU 121 of the scanner section 120 of the copying apparatus 2 is transferred from the ADF CPU (not shown).
Is notified that the document D has been conveyed to a predetermined position, and then the main CPU 161 determines the size of the document D detected via the ADF 8 and the copy magnification set via the control panel 170. The cassette containing the paper P having the optimum size is selected. Then, the read start position of the image data for fetching the image data from the CCD line sensor 24 to the line memory 127 is called from the ROM 162 and then stored in the RAM 163 according to the input copy magnification. At this time, if the size of the paper P calculated by the main CPU 161 based on the size of the original D and the input copy magnification does not match the size of the image area defined according to the copy magnification, the size of the paper P is determined. Based on this, the reading start position, that is, the copyable document area is calculated. Also,
At the same time, the writing start position on the photoconductor drum 30 by the laser exposure device 32 is defined by the same method and then RO
It is read from M162 and stored in the RAM 163.

Since the upper limit of the size of the copyable document area is limited by the maximum size of paper that can be fed by the copying apparatus 2, the maximum size of paper that can be fed is set. If "A3" is set, for example, even if the size of the document D is "B4" and 141% is input as the copy magnification, the size that can be actually copied is "A3".
Limited to 4 "size. Therefore, in this case, the read start position is set to the position corresponding to the “A4” size. Further, for example, when a copy magnification of 105% is input for the original D of “A4” size, “B4” is input.
A cassette accommodating the size P of paper is selected, and the reading start position of the document B is called from the ROM 162 as the reading start position of the document D including the displacement of the reading position corresponding to the copy magnification. . Separately from this, a document D smaller than the “A4” size and larger than the “B5” size is set on the document table 11, and 100
When the copy magnification of% is selected, the cassette accommodating the "A4" size paper P is selected, and
As the reading start position of the document D, the reading start position of the “A4” size document with a copy magnification of 100% is the ROM 162.
Is called from.

Next, the illumination lamp 1 of the first carriage 16
3 is turned on with a predetermined brightness, and the first carriage 16 is moved at a predetermined speed along the document D on the document table 11 by the rotation of a pulse motor (not shown). Then, the image information of the document D placed on the document table 11 is changed to the exposure lamp 1
3 and the reflection plate 14, the first mirror 1 of the first carriage 16 serves as reflected light generated by being illuminated.
5, the second mirror 21 and the third mirror 22 of the second carriage 20 are reflected in order, and an image is formed on the reading surface of the CCD line sensor 24 via the image forming lens 23.

The image information of the original D imaged on the CCD line sensor 24, that is, the reflected light from the original D is photoelectrically converted by the CCD line sensor 24 at a predetermined resolution, and then is read to the reading start position stored in the RAM 163. The pixels of the corresponding CCD line sensor 24 are sequentially picked up from a pixel at a predetermined position (not shown), and the A / D conversion circuit 125 outputs 2 pixels.
The value is binarized, the threshold level is corrected through the shading correction circuit 126, and the result is output to the line memory 127.

The image data input to the line memory 127 is transferred to the image processing unit 167 via the data switching / buffer memory 166 and subjected to predetermined correction and conversion such as character identification and contour correction. ,
It is output to the page memory 145. Page memory 145
The image data input to is converted into a laser drive signal (print signal) through a parallel-serial conversion circuit (not shown), and then supplied to the laser exposure device 32.

In parallel with the reading of the image information of the document D by the scanner section 120 (or at a predetermined timing),
The motor drive circuit 134 is controlled by the control of the main CPU 161.
The motor (not shown) is energized by the supply of the motor drive voltage from the photosensitive drum 30 to rotate the photosensitive drum 30 at a desired speed. At the same time, a predetermined potential is applied from the charging device 31 to the surface of the photoconductor drum 30 by the control of the voltage supply circuit 138. As an example, the initial surface potential supplied to the photoconductor drum 30 is set to about -650 volts.

Subsequently, by the laser exposure device 32,
Image data corresponding to the image of the original D, that is, page memory 145 is stored on the surface of the photoconductor drum 32, and in response to a print signal converted from bitmap data to serial data via a parallel-serial conversion circuit (not shown). The modulated laser beam is emitted. It should be noted that the emission timing of the laser beam emitted from the laser exposure device 32, that is, the writing start position, is not shown based on the writing position stored in the RAM 163 corresponding to the size of the paper P, as described above. It goes without saying that a delay is added from the horizontal synchronizing signal by a predetermined main scanning direction clock.

As a result, an electrostatic latent image corresponding to the print signal (image data) is formed on the outer peripheral surface of the photosensitive drum 30. The electrostatic latent image thus formed is developed by the voltage supply circuit 138, for example, by the toner supplied from the developing roller 33a of the developing device 33 to which the developing bias voltage of −450 V is applied. Then, the toner image is transferred onto the paper P by the transfer output from the transfer / separation charger 34 to which a predetermined transfer voltage is applied by the voltage supply circuit 138.

The toner image transferred to the paper P is transferred to the photosensitive drum 30 together with the paper P by the peeling output from the transfer / peeling charger 34 to which a predetermined peeling voltage is applied by the voltage supply circuit 138 and the peeling claw 35. It is peeled from the surface and conveyed to the fixing device 58 by the conveyor belt 57,
It is fixed on the paper P via the fixing device 58.

The sheet P on which the toner image is fixed is transferred to the copying machine 2 via the first and second discharge rollers 61 and 62.
The sheet is discharged to a sheet discharge tray 59 arranged outside the sheet.
The photoconductor drum 30 on which the toner image is transferred onto the paper P is continuously rotated, the residual toner is removed through the cleaning device 36, and then the charge is removed by the charge removing device 37, and subsequently, it is used for the next image formation.

On the other hand, when the reading of the first document D, which is currently positioned on the document table 11, is completed, the main C
Under the instruction of the scan CPU 121 under the control of the PU 161, the ADF CPU (not shown) is requested to feed the next original D, that is, replace the original D. That is, the transport motor is rotated by the drive current from the motor drive circuit (not shown) to the transport motor (not shown), and the transport belt 76 is rotated.
Is rotated. As a result, the first document currently set on the document table 11 is conveyed toward the reversing roller 78, and the flapper 80 and the discharge roller 81 cover the cover 7.
1 is discharged to the document receiving area formed at a predetermined position.

Next, an empty sensor (not shown) checks whether or not the document D continues, and if the document D remains, the document feeding operation is repeated.
Similarly to the first document, the second document is set on the document table 11, and the image information of the second document is read.

In this way, the document tray 7 of the ADF 8 is
A series of image formation is repeated for all the documents D set to 2. Next, in the copying apparatus shown in FIGS. 1 and 2, a copying operation when the user directly sets the original D on the original table 11 will be described.

FIG. 10 is a flow chart showing an example of the operation of the copying apparatus 2 when the document D is randomly set on the document table 11 by the user. As shown in FIG. 10, when the copying apparatus 2 is in the standby state, after the user sets the document D on the document table 11 and then the control panel 170 is used, the user wants to obtain a copy of a sheet of paper. The size is entered (STP1).

Next, the control panel 1 by the user
The copy magnification to be copied is input by the operation of 70.
(STP2). Next, the copyable original area is defined based on the input paper size and copy magnification (STP
3).

After that, the document position detection sensor 17 determines whether or not the position of the document D set on the document table 11 is "corner reference" (STP4). If it is not detected in step STP4 that the document D is set by the "corner reference" (STP4-No), it is subsequently determined whether or not the document D is set by the "center reference" (STP5). .

When it is detected in step STP5 that the document D is set at the "center reference" (STP5
-Yes), the data of the read start position stored in the RAM 163 is cleared and the RAM 1
“Read delay value T = Q” is set in 63. As described above, “Q” means that when the difference between the reference positions of the corner reference and the center reference is n [mm], and the width of the corresponding document D is P, respectively, Q = It is represented by n − P / 2 (STP6).

Subsequently, the reflected light from the document D is transferred to the RAM 16
3, pixels from a predetermined position (not shown) of the CCD line sensor 24 corresponding to the reading start position stored in FIG. 3, are binarized by the A / D conversion circuit 125, and the threshold level is corrected via the shading correction circuit 126. And output to the line memory 127 (STP
7).

In the following, at the predetermined position of the photosensitive drum 30 to which the predetermined potential is applied according to the image forming operation described above, the delay value T is set to the clock in the main scanning direction based on the writing position stored in the RAM 163. A recording laser beam from the added laser exposure device 32 is irradiated, and an electrostatic latent image corresponding to a state in which the image information of the document D is enlarged or reduced according to the copy magnification is formed on the photosensitive drum 30. . This electrostatic latent image is developed by the developing device 33 and converted into a toner image. The toner image formed on the photoconductor drum 30 by the developing device 33 is transferred to the paper P that has already been fed through the transfer / peel charger 34, and is fixed on the paper P by the fixing device 58 (S
TP8).

On the other hand, when it is detected in step STP4 that the document D is set on the "corner reference" (ST
P4-Yes), the data of the read start position stored in the RAM 163 is cleared and RA
"Read delay T = 0" is set in M163 (STP9).

Thereafter, in steps STP7 and STP8, the image of the document D is copied onto the paper P as in the case where the document D is set at the "center reference". If it is not detected in step STP5 that the document D is set at the "center reference", that is, if neither "corner reference" nor "center reference" is determined (STP5)
-No), the system is once returned to the standby state.

FIG. 11 is a flow chart showing an example of the operation of the copying apparatus 2 when the user inputs the position where the document D is set on the document table 11 via the control panel 170.

As shown in FIG. 11, when the copying apparatus 2 is in the standby state, the user sets the document D on the document table 11 to operate the document position detecting sensor 17 (STP11). Here, when the output from the document position detection sensor 17 is ON (STP11-Ye)
In (s), “1” is set in the flag Fs in the RAM 163 indicating that the document D is set on the document table 11 by “corner reference”. On the other hand, when the output from the document position detection sensor 17 is off (STP11-No), "0" is set in the flag Fs.

Then, the reference change key 186 on the control panel 170 detects whether or not the reference position for setting the document D on the document table 11 has been changed (S).
TP12). Here, when the change of the reference position is input by the control panel 170 (STP12-Ye
s) is a RAM 16 indicating that the reference position has been changed.
The flag Fc in 3 is set to "0". On the other hand, when the change of the reference position is not input by the control panel 170 (STP12-No), "1" is set in the flag Fc.

Next, the contents of the flag Fs and the flag Fc are compared (STP13). Here, when Fs = Fc, that is, Fs = Fc = 0 or Fs = Fc = 1 (ST
(P13-Yes), it is determined that the document D is set on the document table 11 by the "corner reference". In this case, RA
The data of the reading start position stored in M163 is cleared and "read delay T = 0" is set in the RAM 163 (STP14).

Subsequently, the reflected light from the document D is transferred to the RAM 16
3, pixels from a predetermined position (not shown) of the CCD line sensor 24 corresponding to the reading start position stored in FIG. 3, are binarized by the A / D conversion circuit 125, and the threshold level is corrected via the shading correction circuit 126. And output to the line memory 127 (STP
15).

In the following, a delay value T corresponding to the clock in the main scanning direction is set at a predetermined position of the photosensitive drum 30 to which a predetermined potential is applied in accordance with the image forming operation described above, based on the writing position stored in the RAM 163. A recording laser beam from the added laser exposure device 32 is irradiated, and an electrostatic latent image corresponding to a state in which the image information of the document D is enlarged or reduced according to the copy magnification is formed on the photosensitive drum 30. . This electrostatic latent image is developed by the developing device 33 and converted into a toner image. The toner image formed on the photoconductor drum 30 by the developing device 33 is transferred to the paper P that has already been fed through the transfer / peel charger 34, and is fixed on the paper P by the fixing device 58 (S
TP16).

On the other hand, in step STP13, Fs
If either of Fc and Fc is "1" (STP13
-No) means that the document D is set on the document table 11 based on the "center reference". In this case, the data of the read start position stored in the RAM 163 is cleared and the “Read delay value T =
Q "is set. As described above, “Q” indicates that the difference between the reference positions of the corner reference and the center reference is n [m
m], and the corresponding width of the original document D is P, respectively, it is shown by Q = n−P / 2 (STP17).

Hereinafter, steps STP15 and STP1
6, the image of the document D is copied onto the paper P in the same manner as when the document D is set on the “corner basis”. In addition,
Instead of the document position detection sensor shown in FIG. 4, the reference line 12 of the reference display device 12 as shown in FIG.
a for detecting the contact between a and the leading edge of the document D, and detecting the contact between the side regulating member 11a of the document table 11 and one of the two sides in contact with the leading edge of the document D. The side edge detection switch 252 may be arranged. In this case, the side detection switch 252 may be omitted by devising the position where the tip detection switch 251 is arranged.

[0115]

As described above, according to the image forming apparatus of the present invention, the reading start position for reading the image of the document supported by the document table is determined by the "corner reference position" detected by the document position detection sensor. Switched between the "" and "center reference" positions by the CPU.

The position where the reading of the image of the document supported by the document table is started is the "corner reference" position based on the position designated by the reference display device and the position input by the control panel. "Central standard"
The position is switched by the CPU.

Further, the position where the reading of the image of the original image formed on the light receiving surface of the CCD image sensor is started is
Based on the position indicated by the reference display device and the position input by the control panel, the CPU switches between the “corner reference” position and the “center reference” position, and each cassette is input by the control panel. An image is formed corresponding to the position to start the reading changed by the CPU based on the size of the sheet fed by any one of the LCF and the LCF and the manual feeder.

As a result, even when the position where the document is set on the document table is changed, it is possible to provide the image of the document on the paper in a state that is substantially the same as the state where the document is set on the document table. Further, when the user has a plurality of copying machines and the copying machines have both the corner reference and the center reference, it is not desirable that the center of the recording material and the center of the image obtained by copying do not coincide. It is possible to prevent the generation of unnecessary duplicates and reduce the copy cost.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing an image forming apparatus incorporating an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of the image forming apparatus shown in FIG.

3 is a schematic plan view showing an example of a control panel of the image forming apparatus shown in FIGS. 1 and 2. FIG.

FIG. 4 is a schematic view showing the position of a document position detection sensor incorporated in the image forming apparatus shown in FIGS. 1 and 2.

5 is a schematic diagram showing an example of a reference display device incorporated in the image forming apparatus shown in FIGS. 1 and 2. FIG.

FIG. 6 is a schematic diagram showing a difference between a center reference and a corner reference when a document is set on the image forming apparatus shown in FIGS. 1 and 2.

FIG. 7 is a schematic diagram showing a relationship between a reading start position of an image of a document set on the document table of the image forming apparatus shown in FIGS. 1 and 2 on a corner basis and an image reading position of a CCD image sensor.

8 is a schematic diagram showing the relationship between the reading start position of the image of the original set on the original table of the image forming apparatus shown in FIGS. 1 and 2 and the image reading position of the CCD image sensor.

9 is a schematic diagram showing the relationship between the writing position of a laser beam emitted from the laser exposure device toward the photosensitive drum and the size of the sheet in the image forming apparatus shown in FIGS. 1 and 2. FIG.

10 is a flowchart showing a procedure for changing the reading start position of the image of the document in the image forming apparatus shown in FIGS.

11 is a flowchart showing a changing procedure different from the procedure for changing the reading start position of the image of the original shown in FIG.

FIG. 12 is a schematic diagram showing another example of the document position detection sensor shown in FIG.

[Explanation of symbols]

2 ... Digital copying device, 4 ... Image reading unit, 6 ... Image forming unit, 8 ... ADF
(Automatic document feeder) 11, 11 ...
12 ... reference display device, 13 ... exposure lamp,
14 ... Auxiliary reflector, 15 ... First mirror,
16 ... First carriage, 17 ... Document position detection sensor, 17a ... LED element, 17
b ... Photodetector, 20 ... Second carriage, 21 ... Second mirror, 22 ... Third
Mirror, 23 ... Imaging lens, 24 ...
CCD image sensor, 30 ... Photosensitive drum,
31 ... Charging Charger, 32 ... Laser Exposure Device, 33 ... Developing Device, 34 ... Transfer / Peeling Charger, 35 ... Peeling Claw, 36 ... Cleaning Device, 37 ... Eliminating Device, 40 ... Multi-Sheet Feeding Device, 41 ... Upper Cassette, 42 ... Middle cassette, 43 ... Lower cassette, 4
4a, 44b, 44c ... Pickup roller, 45a,
45b, 45c ... Conveying rollers, 46a, 46b, 46c
... Separation roller, 47 ... LCF (Large capacity feeder),
48 ... Pickup roller, 49a ... Conveyor roller,
49b ... Separation roller, 50 ... Manual feeder, 51 ... Pickup roller, 52 ...
Manual feed guide, 53 ... Conveyor rollers, 5
4 ... Conveying path, 55 ... Conveying roller, 56 ... Aligning roller, 56a ... Aligning sensor, 57 ... Conveying belt,
58 ... Fixing device, 59 ... Discharge tray,
60 ... Ejection switching unit, 61 ... First ejection roller, 62 ... Second ejection roller, 63 ... Sorting gate, 64 ... Inversion mechanism, 65 ... Temporary stacking unit, 66 ... Inversion path, 67 ... Pickup roller, 68 ... Inversion transport path, 69
... Paper feed roller, 71 ... Cover, 72
... original feeding table, 73 ... pickup roller, 74 ... sheet feeding roller, 75 ...
Aligning roller, 75a ... Aligning sensor,
76 ... Conveyor belt, 77 ... Belt roller,
78 ... Reversing roller, 79 ... Pinch roller,
80 ... flapper, 81 ... paper ejection roller,
82 ... Jam sensor, 110 ... Control panel section, 111 ... Control panel C
PU, 112 ... ROM, 113 ...
RAM, 120 ... Scanner unit, 121
... scanner CPU, 122 ... ROM,
123 ... RAM, 124 ... Mechanism control unit,
125 ... A / D conversion circuit, 126 ... Shading correction circuit, 127 ... Line memory, 128 ... Editor, 130 ... Printer section, 131
... printer CPU, 132 ... ROM, 13
3 ... RAM, 134 ... Motor drive circuit, 135 ... Input circuit, 136 ...
Mechanism control unit, 137 ... Temperature control circuit, 1
38 ... Voltage supply circuit, 139 ... Laser drive circuit,
140 ... Memory editing unit, 141 ... Memory control CP
U, 142 ... Image editing section, 143 ... Compression / expansion section, 144 ... Enlargement / reduction / rotation section, 1
45 ... Page memory, 146 ... Address control unit, 147 ... Memory management control unit, 148
… Interrupt control unit, 150… System unit,
151 ... System CPU, 152 ... Facsimile device,
153 ... Hard disk device, 154 ... LA
N (Local Area Network), 155 ... Printer controller, 160 ... Main control unit, 161, Main CPU, 162 ... R
OM, 163 ... RAM, 164 ...
Printer font ROM, 165 ... Display font ROM, 166 ... Data switching / buffer memory,
167 ... Image processing unit, 170 ... Control panel, 171 ... Touch panel,
172 ... LCD panel, 173 ... LED panel,
181 ... Numeric keys, 182 ... Clear key,
183 ... Print key, 184 ... All clear key, 185 ... Magnification setting key, 186 ...
Reference change key, 187 ... Copy mode setting key, 188 ... Cassette switching key, 189 ...
Density adjustment key, 201, 202 ...
211-219 ... Luminescent body, 221 ... Corner reference mark,
222 ... Central reference mark, 231-233 ...
Size mark, 234-239 ... Size mark,
251 ... Tip detection switch, 252 ... Side detection switch.

Claims (6)

[Claims] 1. A first position for supporting an original so that only the front end of the original comes into contact with a predetermined position, and one side of the front end of the original and two sides of the original contacting the front. Both of the first position and the second position, the original document supporting unit that supports both of them at a second position, and the position where the original document is set on the original document supporting unit. Reference display means for displaying the first and second reference positions corresponding to either of them, and whether the position of the document set on the document supporting means corresponds to the first position or the second position. Document position detecting means for detecting, paper size setting means for setting the size of the paper for outputting the image of the original set on the original supporting means, and output for the image of the original set on the original supporting means Enter the magnification to Image reading for reading the image of the document set on the document supporting unit with a predetermined width in a direction parallel to the leading end of the document and orthogonal to the leading end as light and dark information of light. Means, the display of the reference display means, the detection result of the document position detection means, the size of the paper set by the paper size setting, and the magnification input by the magnification input means. An image forming apparatus comprising: a reading position control unit that changes a position at which the image reading unit starts reading an image in a direction parallel to the leading end of the document. 2. A document supporting means for supporting a document, a document position detecting means for detecting a first position of the document set on the document supporting means and a second position different from the first position. An image reading unit that reads an image of the document set on the document supporting unit as light and dark information of light, and a position at which the image reading unit starts reading the image of the document is detected by the document position detecting unit. A reading position control unit that switches between the first position and the second position; a sheet feeding unit that feeds a sheet for outputting an image read by the image reading unit; The image of the document read by the reading unit is read at the position where the document is set on the document supporting unit and the predetermined position of the sheet fed through the sheet feeding unit. Image forming means for forming an image corresponding to the position for starting the reading changed by 置制 control means, the image forming apparatus having. 3. A document supporting means for supporting a document, a document position instructing means for instructing the first and second positions at which the document should be set on the document supporting means, and a document supporting means set for the document supporting means. Image reading means for reading the image of the original document as light and dark information of light; original position input means for switching the instruction of the original position instruction means between the first position and the second position; and the image reading means. A sheet feeding unit that feeds a sheet for outputting the image read by the image reading unit; a position at which the image reading unit starts reading the image of the document; A reading position control unit that switches between the first position and the second position based on the position input by the position input unit; The image of the original is changed by the reading position control means to a position where the original is set on the original supporting means and a predetermined position of the paper fed through the paper feeding means. An image forming apparatus including: an image forming unit that forms an image corresponding to a position where reading is started. 4. A document supporting means for supporting a document, a document position instructing means for instructing the first and second positions at which the document should be set on the document supporting means, and a document supporting means set on the document supporting means. Image reading means for reading the image of the original document as light and dark information of light; original position input means for switching the instruction of the original position instruction means between the first position and the second position; and the image reading means. A sheet feeding unit that feeds a sheet for outputting the image read by the image reading unit; a magnification input unit that inputs a magnification for outputting the image read by the image reading unit; The position at which the image reading is started is based on the position designated by the document position designating unit and the position input by the document position input unit, and the first position and the front position. Switching between the second position and the first position and the second position based on the magnification input by the magnification input means and the size of the paper fed by the paper feeding means. And a reading position control unit for changing the position of the document, and an image of the document read by the image reading unit is fed via the sheet feeding unit and the position where the document is set on the document supporting unit. An image forming apparatus, comprising: an image forming unit that forms an image at a predetermined position on the sheet, the image forming unit corresponding to the position to start the reading changed by the reading position control unit. 5. An original supporting means for supporting an original, and a front end of the original contacting when the original is set on the original supporting means, the original being orthogonal to the front end of the original. A first position indicating a position at which the document is set so that the two sides of the document are substantially centered in a direction parallel to the leading end of the document of the document supporting means and the document orthogonal to the leading end of the document. A document position indicating a second position indicating a position where the document is set so that one of the two sides is in contact with one of the two sides of the document supporting unit orthogonal to the leading edge of the document. Means, an image reading means for reading an image of the original document set on the original document supporting means as light and dark information of light, and a position at which the image reading means starts reading the image of the original document as the first position and The second A reading position control means for switching between positions, a paper feeding means for feeding a paper for outputting the image read by the image reading means, and an image of the original read by the image reading means. A position where the original is set on the original supporting means and a predetermined position of the paper fed through the paper feeding means, and a position where the reading is changed by the reading position control means. An image forming apparatus including: an image forming unit that forms an image correspondingly. 6. An original supporting means for supporting an original, and a front end of the original contacting when the original is set on the original supporting means, and the original orthogonal to the front end of the original. A first position indicating a position at which the document is set so that the two sides of the document are substantially centered in a direction parallel to the leading end of the document of the document supporting means and the document orthogonal to the leading end of the document. A document position indicating a second position indicating a position where the document is set so that one of the two sides is in contact with one of the two sides of the document supporting unit orthogonal to the leading edge of the document. Means, image reading means for reading the image of the original document set on the original document supporting means as light and dark information of light, and paper feeding means for feeding the paper for outputting the image read by the image reading means And the above The distance between the first position and the second position is n [m
m], the distance between the two sides of the document is P [mm], and when the document is set at the first position and when the document is set at the second position. When the change amount of the position at which the image reading unit starts reading the image of the original document is Q [mm], the position at which the image reading unit starts reading the image of the original document is Q = n-P / 2. Reading position control means for switching between the first position and the second position, and an image of the original read by the image reading means, at a position where the original is set on the original supporting means. And an image forming unit that forms an image at a predetermined position of the sheet fed through the sheet feeding unit corresponding to the position to start the reading changed by the reading position control unit. , Having image formation apparatus.