JP3628057B2 - Image forming apparatus - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an image forming apparatus that forms an image corresponding to image data by an electrostatic copying process and outputs the image on a sheet.
[0002]
[Prior art]
An image forming apparatus using an electrostatic copying process, for example, an electrophotographic copying apparatus, includes a document holding unit that holds a document to be copied, and image information of the document held by the document holding unit as light contrast information. An image reading unit to be taken out and an image forming unit that forms a copy image based on image information read by the image reading unit and then outputs the copy image to a recording material.
[0003]
The document holding unit includes, for example, a document table formed of a transparent material such as a glass plate, and a document scale that indicates a position where a document to be copied is to be placed.
[0004]
The image reading unit includes an illumination lamp that illuminates a document set on a document table, a CCD reading device that photoelectrically converts reflected light from the document illuminated by the illumination lamp into an electrical signal corresponding to image information, and An imaging lens device is provided for allowing reflected light from the document to enter the light receiving surface of the CCD reading device in a stable state. In general, the reflected light traveling from the document to the CCD reading device is bent multiple times by a plurality of mirrors arranged between the document table and the CCD reading device for the purpose of reducing the installation area of the device, and then the CCD reading. Guided to the light receiving surface of the device.
[0005]
The image forming unit includes a photosensitive member that holds an electrostatic latent image corresponding to an image of a document read by a CCD reading device, a charging device that charges the photosensitive member to a predetermined voltage, and a photosensitive member that is charged by the charging device. An image exposure device that emits image information light for forming an electrostatic latent image, a developing device that develops a developer by supplying a developer to an electrostatic latent image formed on the photoconductor by the image exposure device, and a photoconductor by the developing device The image forming apparatus includes a transfer device that transfers the developer image formed thereon onto a recording material as an image output material, a recording material feeding mechanism that feeds the recording material toward the transfer device, and the like. The developer image transferred to the recording material via the transfer device is melted by being heated by the fixing device, and is fixed to the recording material by the pressure supplied from the fixing device.
[0006]
By the way, as a position reference when setting the document on the document holding unit, an angle reference using two sides of the leading end of the document and one of the two sides in contact with the leading end, the leading end of the document, and the central portion thereof It is known to use the central standard.
[0007]
In the angle-based electrophotographic copying apparatus, it is not necessary to consider the size of the document when setting the document on the document holding unit, and the document should always be set at the same position. However, if the size of the recording material required based on the size of the document and the copy magnification does not match the size of the recording material actually supplied, the copy image obtained by copying is biased toward the corner of the recording material. It is known to be copied. Further, it is known that the recording material feeding mechanism is partially worn or easily changed with time, and that the lens operation of the imaging lens device and the brightness correction associated with the cosine fourth law are complicated.
[0008]
On the other hand, in the case of the central reference electrophotographic copying apparatus, even if the size of the recording material required based on the size of the original and the copying magnification does not match the size of the recording material actually supplied. In the range of a predetermined copying magnification, the image of the original can be copied almost at the center of the recording material. On the other hand, it is known that the center is easily shifted when an original is set on the original platen, and an undesired copy is easily generated.
[0009]
[Problems to be solved by the invention]
By the way, at present, both the above-mentioned angle-based electrophotographic copying apparatus and central-reference electrophotographic copying apparatus are mixed in the market. This causes a problem that undesired copies are frequently generated when the user replaces the copying apparatus used before with a copying apparatus having a different document reference position. In addition, when the user has a plurality of copying machines and the copying machines are both the corner reference and the center reference, a copy of which the center of the recording material and the center of the image obtained by copying do not coincide with each other is obtained. There are problems that are likely to occur.
[0010]
This not only increases copying costs, but also causes problems such as partial consumption of developer, that is, a decrease in image density in a specific area of an image obtained by copying.
An object of the present invention is to provide an image forming apparatus that forms a copy image in the center of a recording material regardless of the position of the original set on the original table.
[0011]
[Means for Solving the Problems]
The present invention has been made on the basis of the above-described problems. The document support means for supporting the document, and the first position of the document set on the document support means is different from the first position. An original position detecting means for detecting the position; an image reading means for reading an image of the original set on the original support means as light contrast information; and a position at which reading of the image of the original is started by the image reading means. A reading position control means for switching between the first position and the second position detected by the document position detecting means, and a sheet for outputting an image read by the image reading means A sheet feeding unit that performs scanning, and an image of the document read by the image reading unit before being fed through the position where the document is set on the document supporting unit and the sheet feeding unit. A predetermined position of the sheet, there is provided an image forming means for forming an image corresponding to the position for starting the reading changed by the reading position control means.
[0012]
According to the present invention, the document supporting means for supporting the document, the document position indicating means for indicating the first and second positions where the document should be set on the document supporting means, and the document supporting means are provided. Image reading means for reading the set image of the document as light contrast information, document position input means for switching the instruction of the document position instruction means between the first position and the second position, and A sheet feeding unit that feeds a sheet for outputting an image read by the image reading unit, and a position at which the image reading unit starts to read the image of the document by the document position instruction unit. And a reading position control means for switching between the first position and the second position based on the position input by the original position input means and the image reading means. The scanned image of the original is changed by the reading position control means to a position where the original is set on the original support means and a predetermined position of the paper fed via the paper feeding means. There is provided an image forming apparatus including an image forming unit that forms an image corresponding to the read start position.
[0015]
Furthermore, according to the present invention, the document supporting means for supporting the document, and the leading edge of the document is contacted when the document is set on the document supporting means, the leading edge of the document being A first position that indicates a position where the document is set so that two sides of the document that are orthogonal to each other are positioned approximately in the center in the direction parallel to the leading edge of the document of the document supporting means, and orthogonal to the leading edge of the document. A second position indicating the position where the original is set is indicated so that one of the two sides of the original is in contact with one of the two sides perpendicular to the front end of the original of the original supporting means. A document position indicating unit, an image reading unit that reads an image of the document set on the document support unit as light brightness information, and a sheet for outputting an image read by the image reading unit. Paper The distance between the feeding means 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 first When the amount of change of the position at which reading of the image of the document is started by the image reading means is Q [mm] depending on whether the document is set at the position or when the document is set at the second position, Q Read 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 according to = n−P / 2, and the image reading The image of the original read by the means is transferred by the reading position control means to a position where the original is set on the original support means and a predetermined position of the paper fed via the paper feeding means. Open the modified reading Image forming apparatus and an image forming means for forming an image corresponding to a position is provided.
[0017]
[Action]
According to the present invention, the position at which reading starts to read the image of the document supported by the document support means is between the first position and the second position detected by the document position detection means. It is switched by. Therefore, even when the position where the document is set on the document support means is changed, the image of the document can be provided on the paper in a state that is almost equal to the state where the document is set on the document support means.
[0018]
According to the present invention, the reading start position for reading the image of the document supported by the document supporting means is based on the position instructed by the document position indicating means and the position input by the document position input means. , Switching between the first position and the second position via the reading position control means. Therefore, even when the position where the document is set on the document support means is changed, the image of the document can be provided on the paper in a state that is almost equal to the state where the document is set on the document support means.
[0019]
Furthermore, according to this invention Read The taking position control means sets the distance between the first position and the second position of the document support means to n [mm], the distance between two sides of the document to P [mm], and the document to the first position. Q = n−P /, where Q [mm] is the amount of change in the position at which reading of the image of the document is started by the image reading means depending on whether it is set at the position or when it is set at the second position 2, since the position where the image reading unit starts reading the image of the document is switched between the first position and the second position, the image of the document read by the image reading unit is An image is formed at a position where the document is set on the support means and a predetermined position of the paper fed via the paper feeding means, corresponding to the position where reading is changed by the reading position control means. Is possible. Thus, even when the position where the document is set on the document support means is changed, the image of the document can be provided on the paper in a state that is almost equal to the state where the document is set on the document support means.
[0020]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 2, the image forming apparatus, that is, the electrophotographic digital copying apparatus 2 includes an image reading unit 4 that functions as a reading unit and an image forming unit 6 that functions as an image forming unit. Note that an upper portion of the image reading unit 4 is formed so as to be openable and closable with respect to a later-described document table of the image reading unit 4, and feeds an object to be read, that is, a document D, one by one toward the document table. An automatic document feeder (hereinafter referred to as “ADF”) 8 that functions as a document press for bringing the document D placed on the document table into close contact with the document table is set.
[0021]
The image reading unit 4 is opposed to the ADF 8 in a closed state at an upper portion thereof, and is placed on a document table 11 made of transparent glass on which a document D is set, and one end of the document table 11. And a reference display device 12 indicating a position where D should be set. A control panel described later with reference to FIG. 3 is disposed in the vicinity of the document table 11 surrounding the document table 11.
[0022]
Below the document table 11, as the configuration of the image reading unit 4, an exposure lamp 13 that illuminates the document D placed on the document table 11, and auxiliary reflection for condensing the light from the exposure lamp 13 on the document D A plate 14 and a first mirror 15 that bends the reflected light from the document D in the left direction in the figure are arranged. The exposure lamp 13, the auxiliary reflector 14, and the first mirror 15 are fixed to the first carriage 16, and are arranged so as to be movable in parallel with the document table 11 as the first carriage 16 moves. The first carriage 16 is moved in parallel along the document table 11 by receiving a driving force of a pulse motor (not shown) via a toothed belt (not shown).
[0023]
Where the document D is set on the document table 11 which will be described later with reference to FIG. 4 at a predetermined position below the document table 11 and near the reference display device 12 and the document table 11. A document position detection sensor 17 for detecting the above is disposed.
[0024]
On the left side of the document table 11 in the drawing, it can be moved in parallel with the document table 11 via a driving mechanism (not shown) such as a toothed belt and a DC motor in the direction in which the reflected light reflected by the first mirror 15 is guided. A second carriage 20 formed in the above is disposed.
[0025]
In the second carriage 20, a second mirror 21 that folds the reflected light from the document D guided by the first mirror 15 downward and a third mirror 22 that folds rightward in the drawing are arranged at right angles to each other. The second carriage 20 is driven by the first carriage 16 by a toothed belt (not shown) that drives the first carriage 16 and is parallel to the first carriage 16 along the document table 11 at a half speed. Moved to.
[0026]
An imaging lens that forms an image of the reflected light from the second carriage 20 at a predetermined magnification in a plane below the first carriage 16 and including the optical axis of the light reflected through the second carriage 20. 23 and a CCD image sensor 24 for converting the reflected light given the focusing property by the imaging lens 23 into an electric signal, that is, image data.
[0027]
The image forming unit 6 includes a photosensitive drum 30 as an image carrier that is rotatably positioned at the center of the copying apparatus 2. The photosensitive drum 30 is rotated at a predetermined rotation speed by a motor (not shown).
[0028]
At a predetermined position around the photosensitive drum 30, a charger 31 for charging the drum surface to a predetermined charge, a laser (not shown) corresponding to image data supplied from an image processing unit described later, that is, image information to be imaged. The laser beam generated from the diode is deflected in the axial direction of the photosensitive drum 30 by a polygon mirror 32a as a deflecting device, and the photosensitive drum 30 is passed through the first and second folding mirrors 32b and 32c and the fθ lens 32d. A laser exposure device 32 that forms an electrostatic latent image on the surface of the photosensitive drum 30 by exposing the surface of the photosensitive drum 30, and an electrostatic latent image formed on the surface of the photosensitive drum 30 by exposure by the laser exposure device 32 A developing device having a developing roller 33a that supplies toner as a developer and develops the toner at a desired image density. 33. To transfer the toner image formed on the photosensitive drum 30 to a transfer material, that is, copy paper P fed from a paper cassette described later, and to separate the paper P on which the toner image has been transferred from the photosensitive drum 30. The transfer / peeling charger 34, the peeling claw 35 for peeling the copy paper P from the surface of the photosensitive drum 30, the cleaning device 36 for cleaning the toner remaining on the surface of the photosensitive drum 30, and the surface of the photosensitive drum 30 A neutralizing device 37 for neutralizing the remaining potential is arranged in order.
[0029]
A multi-stage sheet feeder (hereinafter referred to as “PFP”) is provided at the bottom of the copying apparatus 2 positioned below the photosensitive drum 30 as sheet feeding means detachably mounted in a plurality of stages from the front side of the copying apparatus 2. 40 is disposed integrally with the copying apparatus 2.
[0030]
The PFP 40 includes an upper cassette 41, a middle cassette 42, and a lower cassette 43 for storing a plurality of types of copy paper P of various sizes, and each of the cassettes 41, 42, and 43 is conveyed along the longitudinal direction, for example. Each of the A4 size copy paper, the B4 size copy paper, and the A3 size copy paper placed so as to be stored is formed so as to be capable of storing about 500 sheets.
[0031]
At predetermined positions of the upper cassette 41, the middle cassette 42, and the lower cassette 43, pickup rollers 44a, 44b and 44c for taking out the paper P one by one from the respective cassettes 41, 42 and 43 are arranged.
[0032]
Conveying rollers 45a, 45b for separating the paper P one by one and at positions where the leading ends of the paper P taken out from the cassettes 41, 42 and 43 are passed by the respective pickup rollers 44a, 44b and 44c, and 45c and separation rollers 46a, 46b and 46c arranged integrally with the respective conveying rollers are arranged. The separation rollers 46a, 46b, and 46c are arranged so that their axes are in parallel with the transport rollers combined with each other at a predetermined pressure and rotate in a direction opposite to the rotation direction of the transport rollers. As a result, only the uppermost sheet P of the paper P taken out from each cassette is sent out to a conveyance path described later.
[0033]
On the right side of the PFP 40 in the drawing, a large-capacity feeder (hereinafter referred to as LCF) 47 formed so as to be capable of storing about 3000 sheets of paper P of frequently used size, for example, A4 size paper P, is provided. Yes. At a predetermined position of the LCF 47, a pickup roller 48 for taking out the sheets P stored in the LDF 47 one by one is arranged. A separation mechanism 49 including a transport roller 49a and a separation roller 49b, which are combined in a pair of upper and lower sides, is disposed between the pickup roller 48 and the photosensitive drum 30. The separation mechanism 49 rotates the separation roller 49b in a direction opposite to the direction in which the conveyance roller 49a is rotated, thereby conveying only the uppermost sheet P of the paper P taken out from the LDF 47 by the pickup roller 48, which will be described later. Send to the road.
[0034]
A manual feeder 50 capable of feeding the copy paper P is formed above the LCF 47 independently of the cassettes 41, 42, 43 and the LCF 47. Between the manual feeder 50 and the photosensitive drum 30, a manual pickup roller 51 that takes in the paper P inserted into the manual feeder 50, a manual guide 52 that guides the paper P taken in by the pickup roller 51, and a manual feed A conveyance roller 53 is provided for conveying the paper P guided toward the photosensitive drum 30 via the guide 52.
[0035]
Between each of the cassettes 41, 42 and 43 and the LCF 47 and the photosensitive drum 30, a conveyance path 54 for guiding the paper P from the cassettes 41, 42 and 43 and the LCF 47 toward the photosensitive drum 30 is formed. Yes. The conveyance path 54 further extends to the outside of the copying apparatus 2 through a transfer region defined between the photosensitive drum 30 and the transfer / peeling charger 33. The transport path 54 is provided with a plurality of transport rollers 55 for transporting the paper P fed from any cassette, LCF, or manual feed guide toward the photosensitive drum 30.
[0036]
In the vicinity and upstream of the photosensitive drum 30 in the conveyance path 54, the inclination of the copy paper P guided through the conveyance path 54 is corrected, and the leading edge of the toner image on the photosensitive drum 30 and the copy paper P An aligning roller 56 for feeding the copy paper P to the transfer area at the same speed as the moving speed of the outer peripheral surface of the photosensitive drum 30 is provided. Further, an aligning sensor 56 a that detects the arrival of the copy paper P to the aligning roller 56 is provided in front of the aligning roller 56, that is, on the side of the conveying roller 55.
[0037]
A conveyance belt 57 that conveys the paper P is incorporated in the direction in which the paper P that has passed through the transfer region travels. The sheet in which the sheet P is conveyed by the conveyance belt 57 and is difficult to apply heat to the photosensitive drum 30 includes a pair of heat rollers whose roller surfaces are pressed against each other, and the sheet onto which the toner image has been transferred. A fixing device 58 for fixing the toner image on the paper P by pressing the toner image and the paper P while melting the toner image by heating P is provided.
[0038]
On the side wall of the copying apparatus 2 facing the fixing device 58, a discharge tray 59 for discharging the paper P on which the toner image is fixed by the fixing device 58 is disposed.
Disposed between the fixing device 58 and the discharge tray 59 is a discharge switching unit 60 that guides the copy paper P, on which the toner image has been fixed by the fixing device 58, to either a paper reversing portion described later or the discharge tray 59. Yes.
[0039]
The discharge switching unit 60 is disposed between the first and second discharge rollers 61 and 62 that propel the paper P that has passed through the fixing device 58, and the first and second discharge rollers 61 and 62, and is fixed. A distribution gate 63 is provided for selectively distributing the copy sheet P that has passed through the apparatus 58 to either a discharge tray 59 or a sheet reversing unit described later.
[0040]
The reversing mechanism 64 reverses the front and back of the copy paper P that has already passed through the transfer area and the fixing device 58 and temporarily accumulated the copy paper P that has passed through the fixing device 58 to the temporary stacking portion 65. A reversing path 66 for guiding, a pick-up roller 67 for taking out the copy sheets P collected in the temporary stacking unit one by one, a reversing conveying path 68 for guiding the sheets P stored in the temporary stacking unit 65 to the aligning roller 56 again, and A paper feed roller 69 that feeds the paper P guided to the reverse conveyance path 68 toward the aligning roller 56 is provided.
[0041]
The ADF 8 includes a cover 71, and the rear end edge of the cover 71 is attached to the upper rear end edge of the copying apparatus 2 via a hinge device (not shown), and the entire ADF 8 is rotationally displaced as necessary. Thus, as already described in detail, it is formed to be openable and closable with respect to the document table 11 of the image reading unit 4.
[0042]
A document feeding table 72 that holds a plurality of documents D is provided on the upper surface of the cover 71 and slightly leftward. 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, that is, on one end side of the ADF 8, and the document table 11 of the image reading unit 4 from the left end side in the diagram. A pick-up roller 73 for supplying to one end side of the is disposed. An empty sensor 73 serving as a document detection sensor for detecting whether or not the document D is set on the document feed table 72 is disposed at a predetermined position on the document feed table 72. The document feed table 72 may be provided with a document width detection sensor (not shown) that functions in the same manner as the document position detection sensor 17 that detects the position where the document D is set on the document table 11.
[0043]
In the document take-out direction of the pickup roller 73, the document D picked up by the pickup roller 73 is fed toward the document table 11, and the leading edge of the document D fed by the paper feed roller 74 is aligned. An aligning roller 75 is disposed. Note that an aligning sensor 75 a that detects the arrival of the document D at the aligning roller 75 is disposed between the aligning roller 75 and the paper feed roller 74.
[0044]
A size that covers almost the entire document table 11 is given to the position inside the cover 71 and facing the document table 11 of the image reading unit 4 with the ADF 8 closed. A transport belt 76 is disposed that transports the document D transported from the document feed table 72 via the paper roller 74 and the aligning roller 75 to a predetermined position on the document table 11. The conveyor belt 76 is stretched around a pair of belt rollers 77 arranged on the left and right sides in the figure, and is rotated in both directions on the right side in the figure and the left side in the figure by a belt drive mechanism (not shown).
[0045]
On the right side of the ADF 8, a reverse roller 78 that sends the document D moved from the left side to the right side in the drawing by the conveying belt 76 toward the outside of the cover 71, a pinch roller 79 that presses the document D against the reverse roller 78, The flapper 80 for switching whether the document D conveyed by the reverse roller 78 and the pinch roller 79 is returned to the conveyance belt 76 or discharged onto a predetermined discharge position, that is, on the cover 71, and the flapper 80 are switched to the discharge side. In addition, a paper discharge roller 81 that discharges the document D conveyed by the reversing roller 78, a jam sensor 82 that detects jamming of the document in the vicinity of the reversing roller 78, and the like are disposed.
[0046]
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 will be described later with reference to FIG. A scanner unit 120 that reads the image information of the printer, a printer unit 130 that forms an image on the paper P based on the input image information, a memory unit 140 that processes image data supplied from the scanner unit 120 and an external device described later, For example, a system unit 150 that manages input of image data from a facsimile machine, a hard disk device, a computer and a word processor connected to a known local area network (hereinafter referred to as LAN), and a control panel unit 110, Scanner unit 120, print Part 130 is roughly divided into the main control unit 160 for controlling the delivery of each between the signal of the memory editing section 140 and the system section 150.
[0047]
The control panel unit 110 includes a control panel CPU 111, a read only memory (hereinafter referred to as ROM) 112 and a random access memory (hereinafter referred to as RAM) 113 connected to the control panel CPU 111. .
[0048]
Based on the data stored in the ROM 112 and the RAM 113, the control panel CPU 111 detects input by various switches and touch panels arranged in the control panel and the reference display device 12 which will be described later with reference to FIG. And the lighting and extinguishing of LEDs are controlled.
[0049]
The scanner unit 120 includes a scanner CPU 121 and a ROM 122 and a RAM 123 connected to the scanner CPU 121, and the CCD image sensor 24 of the image reading unit 4 is controlled by the control of the scanner CPU 121 based on control data stored in the ROM 122 and the RAM 123. The mechanism control unit 124 for energizing a DC motor or the like (not shown) for operating the image of the document D as light brightness information and moving the first carriage 16 and the second carriage 20 at a predetermined speed. A predetermined drive signal is output.
[0050]
The scanner unit 120 also converts the analog image data output from the CCD image sensor 24 into a digital signal via an A / D conversion circuit 125 and an A / D conversion circuit 125 that convert the analog image data into a digital signal by a well-known A / D conversion. The shading correction circuit 126 that removes the influence on the individual error of the output of the CCD image sensor 24 and the non-uniformity of the light quantity from the illumination lamp 13 from the converted image signal, and the original D read by the CCD image sensor 24 It has a line memory 127 for supplying image information to the memory editing unit 140 connected to the subsequent stage at a predetermined timing, and is read by the CCD image sensor 24 under the control of the scanner CPU 121 based on the data of the ROM 122 and RAM 123. Image information of document D is electrical signal Binarization to a predetermined threshold level after converted output to the page memory (to be described later) of the memory editing section 140 connected to the subsequent stage.
[0051]
Note that an ADF 8 is also connected to the scanner CPU 121. The ADF 8 feeds the document D under the control of the scanner CPU 121 based on the control by the main control unit 160 described later. In addition, when edit data from a coordinate input device (not shown) is input to the scanner CPU 121, predetermined control data is output to a page memory (to be described later) of the memory editing unit 140 and image data used for image formation. An editor 128 for controlling the size of the memory area for holding the image is also connected.
[0052]
The printer unit 130 includes a printer CPU 131, a ROM 132 and a RAM 133 connected to the printer CPU 131, and is applied to the paper P based on image information read through the image reading unit 4 and image data supplied from an external device described later. Form an image.
[0053]
The printer CPU 131 includes a photosensitive drum 30, a developing roller 33 a of the developing device 33, an aligning roller, a conveying belt, a fixing device, a reversing mechanism, and cassettes 41, 42, and 43 of the multi-stage paper feeding device 40 and an LDF 47. A motor driving circuit 134 for driving a motor (not shown) such as a pick-up roller and a conveying roller and a separation roller disposed in the document, a document position detection sensor 17 for detecting the position of the document D set on the document table 11, each cassette 41, 42 and 43 and a paper empty switch (not shown) arranged in each of the LDFs 47, a lever switch (not shown) arranged at predetermined positions of the conveyance path 54 and the reversing mechanism 64 and detecting a jam of the paper P, and an aligning sensor Switches such as 56a and An input circuit 135 used for inputting a signal output from the sensor, and a mechanism control unit 136 for energizing, for example, a sorting gate 63 of the discharge switching unit 60 or a solenoid (not shown) included in the cleaning device 35. Is connected.
[0054]
The printer CPU 131 also includes a temperature control circuit 137 that controls the temperature of the fixing device 58, a voltage supply circuit 138 that supplies a predetermined voltage to the charging charger, the developing device, the transfer / peeling charger, and the like, and the laser exposure device 32. A laser drive circuit 139 that modulates the intensity of the laser beam emitted from the laser diode corresponding to image data supplied from a page memory to be described later is connected, and the printer CPU 131 based on the data in the ROM 132 and RAM 133 is connected. An image is formed on the paper P by the control.
[0055]
The memory editing unit 140 includes a memory control CPU 141, and an image supplied from the scanner unit 120 or an external device in response to instructions from both a main CPU (to be described later) of the main control unit 160 and a system CPU (to be described later) of the system unit 150. After the data is converted into bitmap data used for intensity modulation of the laser beam emitted from the laser diode of the laser exposure device 32 of the printer unit 130, the data is temporarily stored in a page memory shown later.
[0056]
The memory control CPU 141 uses the image data supplied from the external device via the system unit 150 and the image processing unit, which is read through the scanner unit 120 and then described later, to a predetermined format. An image editing unit 142 that edits the converted image data of the document D, a compression / expansion unit 143 that compresses or expands the input image data, and an enlargement / reduction / rotation that enlarges, reduces, or rotates the input image data A page memory 145 that stores the image data processed by the unit 144, the image editing unit 142, the compression / decompression unit 143, and the enlargement / reduction / rotation unit 144 one page at a time, an address control unit 146 that manages memory addresses, Memory management control unit 147 that manages memory data, and image data captured by image editing unit 142 An interrupt control unit 148 gives an instruction for processing such as compression / decompression and enlargement / reduction / rotation is connected to.
[0057]
The system unit 150 includes a system CPU 151 that controls capturing of image data supplied from other than the scanner unit 120, and includes a facsimile device 152, a hard disk device 153, a computer (not shown), a word processor, and the like as external devices connected to the system CPU 151. Control each of the connected LAN 154 and the printer controller 155 that converts the 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 that can be processed by the copying apparatus 2. Then, the image editing unit 142 of the memory editing unit 140 is caused to input image data.
[0058]
The main control unit 160 has a main CPU 161 that controls the operation of the copying apparatus 2, that is, the CPUs 121, 131, 141, and 151 of the control panel unit 110, scanner unit 120, printer unit 130, memory editing unit 140, and system unit 150. doing.
[0059]
The main CPU 161 includes a ROM 162 that stores initial data for operating the copying apparatus 2, and the control panel unit 110, the scanner unit 120, the printer unit 130, and the memory editing unit under the control of the CPUs 121, 131, 141, and 151. A RAM 163 that holds various data input from each of the unit 140 and the system unit 150 is connected.
[0060]
The main CPU 161 also includes a printer font ROM 164 that holds a printer font used for storing code data input via the system unit 150 in the page memory 145 of the memory editing unit 140, and an editing display device (not shown). A display for displaying a predetermined image on a liquid crystal display / input panel of a control panel, which will be described later with reference to FIG. A display font ROM 165 that holds fonts, and is used for designating a destination of image data read by the scanner unit 120 and switching image data to be supplied to the printer unit 130. The line memory 127 and the memory editing unit 140 of the scanner unit 120 are also used. No page Data switching / buffer memory 166 functioning as a buffer memory for image data transferred between the memory 145 and between the page memory 145 and the laser exposure device 32, and masking or trimming the input image data An image processing unit 167 is connected.
[0061]
FIG. 3 is a schematic plan view showing an example of a control panel incorporated in the copying apparatus shown in FIG.
According to FIG. 3, the control panel 170 is used to specify a plurality of input keys capable of inputting a transmission destination name and the like as a copy condition, an image editing operation, or a facsimile apparatus communication function operation and a facsimile transmission destination. Touch panel 171 and touch panel 171 used as speed dial keys used in speed dial mode for presetting facsimile numbers are formed integrally with touch panel 171 to display the operation status of copying apparatus 2 and ADF 8 or various key areas constituting the touch panel. A liquid crystal display / input device (hereinafter referred to as an LCD panel) 172 and an LED panel 173 for displaying the status of the copying apparatus 2 such as out of paper or paper jam. The LCD panel 172 changes various display patterns and input key areas corresponding to display data stored in the ROM 162 of the main control unit 160, for example, a reference position when the document D is set on the document table 11. A pattern or the like suggesting input of a possible reference position selection mode is displayed.
[0062]
The control panel 170 also includes, for example, numeric keys 181 from 0 to 9 used for inputting the number of copies, a clear key 182 for clearing the number of copies, that is, returning to “1”, a print key 183 for starting copying, and copying. An all clear key 184 for initializing conditions, a magnification setting key 185 for setting a copy magnification, and a reference change key for inputting a change of a reference position for operating the reference display device 12 according to either the center reference or the angle reference. 186, a copy mode setting key 187 for setting a copy mode such as double-sided / double-sided, single-sided / double-sided, and a paper supply source that accommodates paper sizes for printing image data, that is, sheets of different sizes Switching to output a switching signal corresponding to an instruction to switch the cassette and LCF Key 188 and, and density adjustment key 189 for setting the image of the output image formed on a sheet to a predetermined concentration is disposed.
[0063]
4 is a schematic diagram showing an example of a document position detection sensor incorporated in the copying apparatus shown in FIG.
As shown in FIG. 4, the document position detection sensor 17 is located below the document table 11 of the copying apparatus 2 and at the corners of two sides surrounded by the document table 11 and the reference display device 12, that is, on the document table 11. The document D is arranged at a position corresponding to the corner of the area where the document D can be set.
[0064]
The document position detection sensor 17 is, for example, an LED element 17a that emits light of a predetermined wavelength, and a photodetector 17b that is arranged so that reflected light is incident only when the light emitted from the LED element 17a is reflected by the document D. When a reflected light having a predetermined light intensity is incident on the photodetector 17b, a document detection voltage having 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 central reference, when 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 in contact with the end of the document D becomes small, the document position detection sensor 17 is disposed close to the end of the document table 11.
[0065]
FIG. 5 is a schematic plan view showing an example of a reference display device incorporated in the copying apparatus shown in FIG.
The reference display device 12 is disposed from above the document table 11 so as to press down the left end portion 11a of the document table 11 in the drawing.
[0066]
The reference display device 12 includes a display device body 200 and a plurality of light emitters 201, 202, and 211 to 219 incorporated in the display device body 200. Further, reference marks 221 and 222 and size marks 231 to 239 that are independently illuminated when the light emitters 201, 202, and 211 to 219 are lit are arranged on the upper surface of the display device main body 200.
[0067]
The light emitters 201 and 202 illuminate the reference marks 221 and 222 for indicating the reference positions when the document D is set on the document table 11, respectively, and the reference change key 186 of the control panel 170 is pressed. Each time, the light emitter 201 indicating the angle reference and the light emitter 202 indicating the center reference are alternately turned on. Thus, each time the reference change key 186 is pressed, the reference marks 221 and 222 are alternately displayed.
[0068]
The light emitters 211 to 219 illuminate the size marks 231 to 239, respectively. The light emitters 211 to 213 together with the angle reference mark 221 when the angle reference is input via the reference change key 186, respectively. , Size marks 231 to 233 arranged at positions corresponding to the sizes of the documents “A4”, “B4”, and “A3” are displayed. The light emitters 214 to 219 are arranged on two sides of the originals “A4”, “B4”, and “A3” together with the center reference mark 222 when the center reference is input via the reference change key 186. The size marks 234 to 239 arranged at the corresponding positions are displayed.
[0069]
Next, the reference position of the document when the image of the document is copied by the copying apparatus and the operation of 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.
[0070]
As shown in FIG. 6, when an “A3” size document D is set on the document table 11 on the basis of a corner, the leading edge of the document D is brought into contact with the reference line 12 a of the reference display device 12 and the leading edge. One side of the two sides in contact with the side is abutted against the side regulating member 11a of the document table 11 arranged so as to be orthogonal to the reference line 12a. As a result, the document D is set at the upper side of the document table 11 in the drawing and the left side in the drawing with the reference mark 221 shown in FIG. 5 and one of the four corners of the document D aligned.
[0071]
On the other hand, when the “A3” size document D is set on the document table 11 with the center reference, the center of the leading edge of the document D is aligned with the reference mark 222 shown in FIG. The tip of D is in contact with the reference line 12a of the reference display device 12. That is, the “A3” size document D is set between the size marks 238 and 239 shown in FIG.
[0072]
Here, the difference in the reading position of the image of the document D between the corner reference and the center reference of the document A of “A3” size, that is, the position of the side regulating member 11a of the document table 11, that is, the side of the document D in the corner reference. A distance Q between the position of Da and the position of the side Da ′ of the document D at the center reference _A3 When [mm] is obtained, the difference in the reference position between the angle reference and the center reference is n [mm], and the width of the document A of “A3” size is P _A3 [Mm] when indicated respectively
Q _A3 = N-P _A3 / 2
Is required.
[0073]
Similarly, regarding the document D of all sizes, when the difference Q [mm] in the reading position of the image of the document D between the corner reference and the center reference is obtained, the reference position between the corner reference and the center reference is obtained. Is indicated by n [mm] and the width of the corresponding document D is indicated by P [mm].
Q = n−P / 2
Indicated by
[0074]
Next, the relationship between the image reading position of the document D and the writing position of the image formed on the paper P will be described with reference to FIGS.
In general, when the copying apparatus 2 reads an image of the document D set on the document table 11, a first direction in which the image area included in the document D coincides with the longitudinal direction of the CCD image sensor 24, that is, the main scanning direction. And the second direction orthogonal to the main scanning direction, that is, the sub-scanning direction for convenience, and after reading the image information with a width in the predetermined sub-scanning direction with respect to the main scanning direction, the reading is performed once in the sub-scanning direction. A method of photoelectrically converting all image information of the document D by shifting the reading position by an amount corresponding to the obtained width in the sub-scanning direction and repeating the document D length method is used.
[0075]
In many cases, the direction in which the axes of the illumination lamp 13 and the photosensitive drum 30 of the first carriage 16 are extended, that is, the direction in which the reference display device 12 is extended coincides with the main scanning direction, and the first carriage 16 is The direction of movement and the direction in which the tourism attitude m 30 is rotated, that is, the direction orthogonal to the reference line 12a of the reference display device 12, and the sub-scanning direction are matched.
[0076]
Thereby, the reflected light from the area of the predetermined width of the document D illuminated by the illumination lamp 17 of the first carriage 16 is reflected in turn by the first mirror 15, the second mirror 21 and the third mirror 22, and then the imaging lens. The first image information in the main scanning direction having a predetermined width in the sub-scanning direction is photoelectrically converted by the image forming unit 23 on the light receiving surface of the CCD image sensor 24. Subsequently, the first carriage 16 is moved by a predetermined width in the sub-scanning direction, whereby 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 by the CCD image sensor 24 in order. Thus, the image information of the document D is read as light / dark information by the illumination lamp 17 being illuminated. Note that 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 limited to the reading resolution inherent to the CCD image sensor 24 or the reading resolution inherent to the CCD image sensor 24. According to the resolution corresponding to the input from the control panel, for example, 1/400 dot per inch (hereinafter referred to as [dpi]) or 1/200 [dpi] is specified.
[0077]
By the way, as shown in FIG. 7A, when the document D is set with reference to the corner, the reading start position when the image information of the document D is read via the CCD image sensor 24 is shown in FIG. b) When the document D is viewed from the front surface, that is, the image information surface of the document D, as shown in FIG. 5B, it is coincident with the left end of the image reading position of the CCD image sensor 24 regardless of the size of the document D, ie, the document size.
[0078]
On the other hand, when the document D is set with the center reference as shown in FIG. 8A, 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. 8B, the size of the document D, that is, the reading start position unique to the document size is matched.
[0079]
On the other hand, the laser exposure device 32 of the copying apparatus 2 has a writing position obtained from the relative position between the sheet P fed to the photosensitive drum 30 from each of the PFP 40, the LCF 47, and the manual feeder 50 and the photosensitive drum 30. The laser beam corresponding to the image data to be imaged is irradiated.
[0080]
By the way, the paper P fed toward the photosensitive drum 30 has passed through a partial wear or fixing device of a paper transport mechanism represented by various rollers and a transport belt for transporting the paper P. In order to prevent “wrinkles” that may occur on the paper P, the center of the main scanning direction and the center of the paper P in the direction perpendicular to the direction in which the paper P is conveyed are matched regardless of the paper size. Sent.
[0081]
For this reason, as shown in FIG. 9, the writing position of the laser beam irradiated from the laser exposure device 32 toward the photosensitive drum 30 is defined in advance according to the size of the paper P on which the image is formed. Must be matched to a specific export. Since the size of the paper P is defined according to the size of the original D and the copy magnification input from the control panel 170, the writing position of the laser beam from the laser exposure device 32 is the same as the size of the original D. It goes without saying that it does not depend on this.
[0082]
That is, the writing start position, that is, the writing timing of the laser beam emitted from the laser exposure device 32 toward the photosensitive drum 30 is set on the document table 11 by the “corner reference” or “center reference” method. Even when the size of the paper P is “A3”, the difference in the size of the paper Pn actually used (n indicates the size of the paper) is expressed as x [mm. , And the delay of the writing position with respect to the paper Pn is y [mm], when the size of the paper Pn is “A4”,
y _A4 = X _A4 / 2
Similarly, when the size of the paper Pn is “B4”,
y _B4 = X _B4 / 2
As shown by the above, a unique writing position is given to the size of the paper P.
[0083]
Next, an operation for copying a document image by the copying apparatus shown in FIGS. 1 and 2 will be described.
The copying apparatus 2 is warmed up and initialized according to a control program stored in the ROM 162 when a main switch (not shown) is turned on. The ADF 8 is also initialized according to a control program stored in an ADFROM (not shown) according to an instruction from the scanner CPU 121 of the scanner unit 120 under the control of the main CPU 161. It is assumed that the ADF 8 feeds the document D to the document table 11 with “center reference”.
[0084]
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, it is checked by an ADF CPU (not shown) that an empty sensor (not shown) of the ADF 8 is turned on. When it is detected by the empty sensor that the document D is set on the document tray 72, the pickup roller 73 is driven in accordance with the supply of a drive current from a motor drive circuit (not shown) to a paper feed motor (not shown). The lowermost document of the document D set on the tray 72 is guided to the paper feed roller 74. The document D guided to the sheet feeding roller 74 is further conveyed toward the aligning roller 75.
[0085]
Subsequently, when the leading edge of the document D passes through the aligning sensor 75a, a clutch (not shown) is turned on via an ADF mechanism control unit (not shown), and the aligning roller 75 is stopped. As a result, the document D taken out from the document tray 72 by the pickup roller 73 is temporarily stopped, whereby the inclination of the document D with respect to the document conveyance direction is corrected. After that, the belt roller 77 is rotated in the first direction, that is, the document feeding direction by a driving motor (not shown), and the conveying belt 76 is rotated. Then, a clutch (not shown) is turned off at a predetermined timing. The document D is fed to the transport belt 76. Thereafter, the conveyance belt 76 is rotated by the conveyance motor for a predetermined time, whereby the document D is conveyed onto the document table 11 of the copying apparatus 2. The conveyance belt 76 is stopped after a predetermined time has elapsed since the trailing edge of the document D has passed through the aligning sensor 75a, that is, a time determined in advance by the interval between the aligning sensor 75a and the reference indicating device 12. Rotation due to inertia is prevented by a brake (not shown).
[0086]
When the leading edge of the document D is detected by the aligning sensor 75a, the ADF CPU (not shown) notifies the scanner CPU 121 of the scanner unit 120 of the copying apparatus 2 that the document D has been conveyed to a predetermined position. Based on the size of the document D detected via the ADF 8 and the copy magnification set via the control panel 170, the main CPU 161 selects a cassette containing the paper P having the optimum size. Subsequently, the read start position of the image data to be read from the CCD line sensor 24 to the line memory 127 is called from the ROM 162 and 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 document 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 The reading start position based on the height, that is, the copyable document area is calculated. At the same time, the writing start position on the photosensitive drum 30 by the laser exposure device 32 is defined by the same method, and then read from the ROM 162 and stored in the RAM 163.
[0087]
Since the upper limit of the size of the copyable document area is limited by the maximum paper size that can be fed by the copying apparatus 2, the maximum paper size that can be fed is set to “A3”. Then, for example, even when the size of the document D is “B4” and 141% is input as the copy magnification, the actually copyable size is limited to the size of “A4”. Therefore, in this case, the reading start position is set to a position corresponding to the “A4” size. Further, for example, when a copy magnification of 105% is input to the “A4” size document D, a cassette containing the “B4” size paper P is selected and the document D is read. As the start position, the read start position of the “B4” size document including the displacement of the read position corresponding to the copy magnification is called from the ROM 162. Separately, when an original D smaller than the “A4” size and larger than the “B5” size is set on the original platen 11 and a copying magnification of 100% is selected, an “A4” size paper P is loaded. While the accommodated cassette is selected, the reading start position of the “A4” size document with a copy magnification of 100% is called from the ROM 162 as the reading start position of the document D.
[0088]
Next, the illumination lamp 13 of the first carriage 16 is turned on with a predetermined brightness, and the first carriage 16 is moved at a predetermined speed along the original D on the original table 11 by the rotation of a pulse motor (not shown). . Subsequently, the image information of the document D placed on the document table 11 is reflected as light generated by being illuminated through the exposure lamp 13 and the reflection plate 14, and the first mirror 15 of the first carriage 16 and The second mirror 21 and the third mirror 22 of the second carriage 20 are sequentially reflected and imaged on the reading surface of the CCD line sensor 24 via the imaging lens 23.
[0089]
The image information of the document D imaged on the CCD line sensor 24, that is, the reflected light from the document D is photoelectrically converted at a predetermined resolution by the CCD line sensor 24, and then the CCD corresponding to the reading start position stored in the RAM 163. The pixels are taken in order from a pixel at a predetermined position (not shown) of the line sensor 24, binarized by the A / D conversion circuit 125, the threshold level is corrected via the shading correction circuit 126, and output to the line memory 127.
[0090]
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 is subjected to predetermined correction and conversion such as character specification and contour correction, for example, and the page memory. It is output to 145. The image data input to the page memory 145 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.
[0091]
In parallel with the reading of the image information of the document D by the scanner unit 120 (or at a predetermined timing), a motor (not shown) is energized by the supply of the motor drive voltage from the motor drive circuit 134 under the control of the main CPU 161, and the photosensitive member. The drum 30 is rotated at a desired speed. At the same time, a predetermined potential is applied from the charging device 31 to the surface of the photosensitive drum 30 under the control of the voltage supply circuit 138. For example, the initial surface potential supplied to the photosensitive drum 30 is set to approximately −650 volts.
[0092]
Subsequently, the image data corresponding to the image of the document D, that is, the page memory 145 is stored on the surface of the photosensitive drum 32 by the laser exposure device 32, and the serial data is converted from the bitmap data through a parallel-serial conversion circuit (not shown). A laser beam modulated in accordance with the print signal converted into is irradiated. Note 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 already described. Needless to say, a delay corresponding to a predetermined main scanning direction clock is added from the horizontal synchronizing signal.
[0093]
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 formed in this way is developed by the voltage supply circuit 138 with toner supplied from the developing roller 33a of the developing device 33 to which a developing bias voltage of −450 volts is applied, for example. In addition, the toner image is transferred onto the paper P as a toner image by the transfer output from the transfer / peeling charger 34 to which a predetermined transfer voltage is applied by the voltage supply circuit 138.
[0094]
The toner image transferred to the paper P is peeled from the surface of 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. Then, the toner is conveyed to the fixing device 58 by the conveying belt 57 and fixed on the paper P via the fixing device 58.
[0095]
The sheet P on which the toner image is fixed is discharged to a discharge tray 59 disposed outside the copying apparatus 2 via first and second discharge rollers 61 and 62.
The photosensitive drum 30 having the toner image transferred onto the paper P is continuously rotated, and after the residual toner is removed through the cleaning device 36, it is neutralized by the neutralizing device 37, and subsequently used for the next image formation.
[0096]
On the other hand, when reading of the first document D currently located on the document table 11 is completed, the next document D is fed to the ADF CPU (not shown), that is, the document by an instruction of the scan CPU 121 under the control of the main CPU 161. A replacement of D is required. That is, the conveyance motor is rotated by the drive current from the motor drive circuit (not shown) to the conveyance motor (not shown), and the conveyance belt 76 is rotated. As a result, the first document currently set on the document table 11 is conveyed toward the reverse roller 78, and is discharged to the document receiving area formed at a predetermined position of the cover 71 by the flapper 80 and the discharge roller 81. Is done.
[0097]
Subsequently, an empty sensor (not shown) checks whether or not there is a subsequent document D, and if the document D remains, the document feeding operation is repeated, and the document table 11 is subsequently repeated in the same manner as the first document. Then, the second document is set and the image information of the second document is read.
[0098]
In this way, a series of image formation is repeated for all the originals D set on the original tray 72 of the ADF 8.
Next, in the copying apparatus shown in FIGS. 1 and 2, the copying operation when the document D is directly set on the document table 11 by the user will be described.
[0099]
FIG. 10 is a flowchart 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 a standby state, the user sets a document D on the document table 11, and then a sheet of a size that the user wants to obtain a copy through the control panel 170. The size is entered (STP1).
[0100]
Next, the copy magnification to be copied is input by the operation of the control panel 170 by the user (STP2).
Subsequently, a copyable document area is defined based on the input paper size and copy magnification (STP3).
[0101]
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 with the “corner reference” (STP4-No), it is subsequently determined whether or not the document D is set with the “center reference” (STP5). .
[0102]
When it is detected in step STP5 that the document D is set at “center reference” (STP5-Yes), the data of the reading start position stored in the RAM 163 is cleared and the “reading” is stored in the RAM 163. Delay value T = Q "is set. Note that “Q” is indicated when the difference in the reference position between the angle reference and the center reference is n [mm] and the width of the corresponding document D is P, as already described.
Q = n−P / 2
(STP6).
[0103]
Subsequently, the reflected light from the document D is sequentially captured from a pixel at a predetermined position (not shown) of the CCD line sensor 24 corresponding to the reading start position stored in the RAM 163, and binarized by the A / D conversion circuit 125, and then shading is performed. The threshold level is corrected through the correction circuit 126 and output to the line memory 127 (STP7).
[0104]
Thereafter, a delay value T is added to a predetermined position of the photosensitive drum 30 to which a predetermined potential is applied in accordance with the image forming operation already described based on the main scanning direction clock based on the writing position stored in the RAM 163. The recording laser beam from the 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 copying 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 photosensitive drum 30 by the developing device 33 is transferred to the paper P that has already been fed via the transfer / peeling charger 34, and is fixed to the paper P by the fixing device 58 (STP8). .
[0105]
On the other hand, when it is detected in step STP4 that the document D is set with the “corner reference” (STP4-Yes), the data of the reading start position stored in the RAM 163 is cleared and the RAM 163 stores the data. “Reading delay T = 0” is set (STP9).
[0106]
Thereafter, in steps STP7 and STP8, the image of the document D is copied onto the paper P in the same manner as when the document D is set with “center reference”. If it is not detected in step STP5 that the document D is set at “center reference”, that is, if neither “corner reference” nor “center reference” is determined (STP5-No), the standby state is temporarily entered. Returned.
[0107]
FIG. 11 is a flowchart illustrating an example of the operation of the copying apparatus 2 when a user inputs a position where the document D is set on the document table 11 via the control panel 170.
[0108]
As shown in FIG. 11, when the copying apparatus 2 is in the standby state, the document position detection sensor 17 is operated by setting the document D on the document table 11 by the user (STP11). Here, when the output from the document position detection sensor 17 is on (STP11-Yes), the flag Fs in the RAM 163 “1” is set to “1” indicating that the document D is set on the document table 11 with “corner reference”. Is set. On the other hand, when the output from the document position detection sensor 17 is OFF (STP11-No), “0” is set to the flag Fs.
[0109]
Subsequently, it is detected by the reference change key 186 of the control panel 170 whether or not the reference position for setting the document D on the document table 11 has been changed (STP12). Here, when the change of the reference position is input from the control panel 170 (STP12-Yes), “0” is set to the flag Fc in the RAM 163 indicating that the reference position has been changed. On the other hand, when the change of the reference position is not input from the control panel 170 (STP12-No), “1” is set to the flag Fc.
[0110]
Next, the contents of the flag Fs and the flag Fc are compared (STP13). Here, when Fs = Fc, that is, when Fs = Fc = 0 or Fs = Fc = 1 (STP13-Yes), it is determined that the document D is set on the document table 11 with the "angle reference". In this case, the data of the reading start position stored in the RAM 163 is cleared, and “reading delay T = 0” is set in the RAM 163 (STP14).
[0111]
Subsequently, the reflected light from the document D is sequentially captured from a pixel at a predetermined position (not shown) of the CCD line sensor 24 corresponding to the reading start position stored in the RAM 163, and binarized by the A / D conversion circuit 125, and then shading is performed. The threshold level is corrected via the correction circuit 126 and output to the line memory 127 (STP15).
[0112]
Thereafter, a delay value T is added to a predetermined position of the photosensitive drum 30 to which a predetermined potential is applied in accordance with the image forming operation already described based on the main scanning direction clock based on the writing position stored in the RAM 163. The recording laser beam from the 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 copying 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 photosensitive drum 30 by the developing device 33 is transferred to the paper P that has already been fed via the transfer / peeling charger 34, and is fixed to the paper P by the fixing device 58 (STP16). .
[0113]
On the other hand, if either Fs or Fc is “1” in step STP13 (STP13-No), the document D is set on the document table 11 with “center reference”. In this case, the data of the reading start position stored in the RAM 163 is cleared and “reading delay value T = Q” is set in the RAM 163. Note that “Q” is indicated when the difference in the reference position between the angle reference and the center reference is n [mm] and the width of the corresponding document D is P, as already described.
Q = n−P / 2
(STP17).
[0114]
Thereafter, in steps STP15 and STP16, the image of the document D is copied onto the paper P in the same manner as when the document D is set with the “corner reference”.
Note that, instead of the document position detection sensor shown in FIG. 4, a leading edge detection switch for detecting that the reference line 12a of the reference display device 12 and the leading edge of the document D contact each other as shown in FIG. A side detection switch 252 that detects that 251 and the side regulating member 11a of the document table 11 are in contact with one of the two sides in contact with the leading edge of the document D may be disposed. In this case, the side detection switch 252 may be omitted by devising the position where the tip detection switch 251 is arranged.
[0115]
【The invention's effect】
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 the “corner reference” position detected by the document position detection sensor and the “center”. The CPU switches between the “reference” position.
[0116]
In addition, the reading start position for reading the image of the document supported by the document table is based on the position designated by the reference display device and the position input by the control panel, and the “corner reference” position and the “center reference position”. The position is switched by the CPU.
[0117]
Further, the position at which reading of the image of the original image formed on the light receiving surface of the CCD image sensor is started is determined by the CPU based on the position designated by the reference display device and the position input by the control panel. It is switched between the “reference” position and the “central reference” position, and is changed by the CPU based on the size of the sheet fed by each cassette, LCF, and manual feeder when input from the control panel. An image is formed corresponding to the position where reading is started.
[0118]
As a result, even when the position where the document is set on the document table is changed, the image of the document can be provided on the sheet in a state substantially equal to the state where the document is set on the document table. Further, when the user has a plurality of copying apparatuses and the copying apparatuses are both the angle reference and the center reference, the center of the recording material and the center of the image obtained by copying are not desired. Can be prevented, and the copy cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram showing an image forming apparatus in which an embodiment of the present invention is incorporated.
2 is a schematic 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.
4 is a schematic diagram showing the position of a document position detection sensor incorporated in the image forming apparatus shown in FIGS. 1 and 2. FIG.
FIG. 5 is a schematic diagram illustrating an example of a reference display device incorporated in the image forming apparatus illustrated in FIGS. 1 and 2;
6 is a schematic diagram showing a difference between a center reference and a corner reference when an original is set on the image forming apparatus shown in FIGS. 1 and 2. FIG.
7 is a schematic diagram showing a relationship between an image reading start position of a document set on the document table of the image forming apparatus shown in FIGS. 1 and 2 on the basis of a corner and an image reading position of a CCD image sensor. FIG.
8 is a schematic diagram showing a relationship between an image reading start position of an original set on the original table of the image forming apparatus shown in FIGS. 1 and 2 and a CCD image sensor image reading position. FIG.
9 is a schematic diagram showing a relationship between a writing position of a laser beam emitted from a laser exposure device toward a photosensitive drum and a size of a sheet in the image forming apparatus shown in FIGS. 1 and 2. FIG.
10 is a flowchart showing a procedure for changing a reading start position of an image of a document in the image forming apparatus shown in FIGS. 1 to 5. FIG.
FIG. 11 is a flowchart showing a changing procedure different from the procedure for changing the reading start position of the document image shown in FIG. 10;
12 is a schematic diagram showing another example of the document position detection sensor shown in FIG.
[Explanation of symbols]
2 ... digital copying machine, 4 ... image reading unit,
6 ... image forming unit, 8 ... ADF (automatic document feeder),
11 ... manuscript table, 12 ... reference display,
13 ... exposure lamp, 14 ... auxiliary reflector,
15 ... 1st mirror, 16 ... 1st carriage,
17: Document position detection sensor, 17a: LED element,
17b ... photo detector, 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 nail,
36 ... Cleaning device, 37 ... Static elimination device,
40 ... multi-stage paper feeder, 41 ... upper cassette,
42 ... middle cassette, 43 ... lower cassette,
44a, 44b, 44c ... pickup roller,
45a, 45b, 45c ... conveying rollers,
46a, 46b, 46c ... separation rollers,
47 ... LCF (Large Capacity Feeder), 48 ... Pickup roller,
49a ... Conveying roller, 49b ... Separating roller,
50: Manual feeder, 51 ... Pickup roller,
52 ... Manual feed guide, 53 ... Conveying roller,
54 ... conveying path, 55 ... conveying roller,
56 ... Aligning roller, 56a ... Aligning sensor,
57 ... Conveying belt, 58 ... Fixing device,
59 ... discharge tray, 60 ... discharge switching unit,
61 ... 1st discharge roller, 62 ... 2nd discharge roller,
63 ... Sorting gate, 64 ... Reversing mechanism,
65 ... Temporary stacking unit, 66 ... Inversion path,
67 ... Pickup roller, 68 ... Reverse conveyance path,
69 ... feed roller 71 ... cover,
72: Document feeding table 73: Pickup roller,
74 ... feed roller, 75 ... aligning roller,
75a ... aligning sensor, 76 ... conveyor belt,
77 ... Belt roller, 78 ... Reverse roller,
79 ... Pinch roller, 80 ... Flapper,
81 ... paper discharge roller, 82 ... jam sensor,
110 ... Control panel section, 111 ... Control panel CPU,
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,
133 ... RAM, 134 ... motor drive circuit,
135: input circuit, 136: mechanism control unit,
137 ... Temperature control circuit, 138 ... Voltage supply circuit,
139 ... Laser drive circuit, 140 ... Memory editing section,
141: Memory control CPU, 142: Image editing unit,
143 ... compression / decompression unit, 144 ... enlargement / reduction / rotation unit,
145: Page memory, 146: Address control unit,
147 ... Memory management control unit, 148 ... Interrupt control unit,
150 ... System part 151 ... System CPU,
152 ... facsimile machine, 153 ... hard disk drive,
154 ... LAN (Local Area Network)
155 ... Printer controller, 160 ... Main control unit,
161: main CPU, 162: ROM,
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 ... Standard change key, 187 ... Copy mode setting key,
188 ... cassette switching key, 189 ... density adjustment key,
201, 202 ... luminous body, 211-219 ... luminous body,
221 ... Corner reference mark, 222 ... Center reference mark,
231 to 233 ... size mark, 234 to 239 ... size mark,
251 ... Tip detection switch, 252 ... Side detection switch.

Claims (3)

A first position where the document is supported so that only the leading edge of the document is in contact with a predetermined position, and the leading edge of the document and one of the two sides of the document in contact with the leading edge are predetermined. Document supporting means for supporting at any one of the second positions for supporting the position;
Reference display means for displaying a first reference position and a second reference position corresponding to either the first position or the second position as a position where the original is set on the original support means;
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 paper for outputting the image of the original set on the original support means;
A magnification input means for inputting a magnification for outputting an image of the document set on the document support means;
Image reading means for reading the image of the document set on the document support means as light brightness / darkness information with a predetermined width in a direction parallel to the leading edge of the document and perpendicular to the leading edge;
The image reading means based on 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. Reading position control means for changing a position at which reading of an image in a direction parallel to the leading edge of the document is started,
An image forming apparatus. Document support means for supporting the document;
Document position detection means for detecting a first position of the document set on the document support means and a second position different from the first position;
Image reading means for reading an image of the original set on the original support means as light contrast information;
A reading position control means for switching between the first position and the second position detected by the document position detecting means, a position at which reading of the image of the document is started by the image reading means;
Paper feeding means for feeding paper for outputting the image read by the image reading means;
The image of the original read by the image reading means is placed at a position where the original is set on the original supporting means and a predetermined position of the paper fed via the paper feeding means. An image forming means for forming an image corresponding to the position where the reading is started changed by the control means;
An image forming apparatus. Document support means for supporting the document;
When the document is set on the document support means, the leading edge of the document is brought into contact, and two sides of the document perpendicular to the leading edge of the document are the leading edge of the document on the document supporting means. A first position that indicates a position where the document is set to be positioned approximately in the center in a parallel direction, and one of the two sides of the document that is orthogonal to the leading edge of the document is the one of the document support means. An original position indicating means for indicating a second position for instructing a position where the original is set so as to be in contact with one of two sides orthogonal to the leading edge of the original ;
Image reading means for reading an image of the original set on the original support means as light contrast information;
A paper feeding means for feeding paper for outputting an image read by the image reading means;
The distance between the first position and the second position is n [ mm ] ,
The distance between the two sides of the document is P [ mm ] , and
The amount of change in the position at which the image reading unit starts reading the image of the original is set by Q.sub.2 when the original is set at the first position and when the original is set at the second position . when the mm],
Q = n−P / 2
Accordingly, the position to start reading of an image of said original by said image reading means, a reading position control means switches between the pre-Symbol first position and said second position,
The image of the original read by the image reading means is placed at a position where the original is set on the original supporting means and a predetermined position of the paper fed via the paper feeding means. An image forming means for forming an image corresponding to the position where the reading is started changed by the control means;
An image forming apparatus.

Images