JPH1169096A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily set an image forming mode or image forming conditions by detecting the position of an original from read image data, selecting a prescribed image forming mode and controlling copy operation, based on the set image forming conditions. SOLUTION: In preliminary scanning, the output of a line sensor is binarized in an original area detection part 29 after image processing and stored in an area memory to which two-dimensional (x) and (y) addresses are set. Therefore, image data reproduce the state on platen glass. Then, a book mode is set from the detected original placing position but when it is not the book mode, a binding amount and an erase amount are set corresponding to the selected editing mode and a magnification, paper size and select paper size are determined in response to the copy mode. Afterwards, the main scanning of original images is performed and provided image data are stored in a memory unit, transferred to a print processing unit 40 and outputted.

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, and more particularly, to an image forming apparatus capable of detecting a document placement position and an image area based on image data.

[0002]

2. Description of the Related Art In a digital image forming apparatus, an image of a document placed on a document table is read by a CCD or the like to generate image data for each pixel.
The image is output on paper by the image forming means. The digital image forming apparatus can detect a document placement position and an image area based on image data. Various image forming apparatuses that form images using read image data have been proposed. For example, an image reading apparatus described in Japanese Patent Laid-Open No. 61-244169 discriminates a document image area and outputs only image data of the document image area to a printer. Thus, the original can be placed at an arbitrary position on the original table. Further, JP-A-62-1370 and JP-A-2-3325.
Japanese Patent Application Laid-Open No. 4 (2004) discloses that an image outside a document area is erased. Further, Japanese Patent Laid-Open No. 2-188060 discloses that a read image is temporarily displayed on a monitor, and for a specified area on the monitor, erasing outside the area, automatic paper selection, or automatic magnification selection is performed. Have been. In the conventional image forming apparatus, various copy modes and copy conditions are set using switches on an operation panel or keys on a liquid crystal touch panel.

[0003]

However, the above-mentioned Japanese Patent Application Laid-Open Nos. 61-244169 and 62-137 describe above.
In the apparatus described in Japanese Patent Application Laid-Open No. 0-233204 or Japanese Patent Application Laid-Open No. 2-33254, an original can be placed at an arbitrary position on an original platen. It merely shows that image data is formed on paper of various sizes. In addition, Japanese Patent Application Laid-Open No. 2-1880
In the image forming apparatus disclosed in Japanese Patent Laid-Open No. 60-160, various editing processes are possible. However, since image editing can only be performed after an area is designated using a dedicated menu, the operation is complicated and the operation requires a long time. Further, in the conventional image forming apparatus, various copy modes are set using switches on the operation panel or keys on the liquid crystal touch panel.
The operation is complicated, and setting the copy mode takes a long time. Further, as the number of modes mounted on the copier increases, the number of mode setting keys on the operation panel also increases, and the configuration becomes complicated and the operation becomes complicated.

An object of the present invention is to provide an image forming apparatus which can easily set an image forming mode and image forming conditions.

[0005]

According to a first aspect of the present invention, there is provided a first image forming apparatus, comprising: reading means for reading a document placed on a document table; and image data of the document read by the reading means. Position detecting means for detecting the position of the document placed on the table; mode selecting means for selecting a predetermined image forming mode; and image forming conditions based on the position of the document detected by the position detecting means. Image forming condition setting means for setting the image forming mode, and control means for controlling the copying operation based on the image forming conditions set by the image forming condition setting means in the image forming mode selected by the image forming mode selecting means. . Thus, when the predetermined image forming mode is selected by the mode selecting means, the image forming mode setting means sets the image forming mode based on the interval between the predetermined position on the document platen and the document detected by the position detecting means. Set conditions automatically. Preferably, the image forming condition setting means sets the image forming condition based on a distance between a predetermined position on the document table and a position of a predetermined portion of the document detected by the position detecting means. For example, the predetermined image forming mode is an automatic magnification setting mode. Here, the image forming condition is a sheet size, a position of the predetermined portion of the document is a position of a portion farthest from a predetermined position on the document table, and the image forming condition setting unit includes: A paper size is determined based on a distance between a predetermined position on the platen and a position of a predetermined portion of the document detected by the position detecting means. Further, the position of the document detected by the position detecting means and the sheet size are determined. And automatically set the magnification of the output image. For example, the predetermined position on the platen is the lower left corner of the platen,
An original is set with the lower left end (position farthest from a predetermined position on the original platen) aligned with the size index on the original scale on the original platen, and image formation is started. Thus, the preliminary scanning is performed, and the document area is detected. As a result, the size indicated by the index including the lower left end of the document is set as the paper size. Then, the magnification of the output image is calculated based on the document size obtained from the detected document area and the above-mentioned paper size, and the reading magnification is set. Further, preferably, the image forming condition setting means,
An image forming condition is set based on an interval between a predetermined position on the document table and the document detected by the position detecting means.
For example, the predetermined image forming mode is an erase mode, and the image forming condition is an erase amount indicating a range in which an image is erased during image formation. Also, for example, the predetermined copy mode is a binding margin mode, and the image forming condition is a binding margin representing a length of shifting an image position during image formation. Assuming that the predetermined position on the platen is the lower right corner of the platen, the user selects the erase mode or the binding margin mode as the predetermined copy mode, and moves the document to a desired erase amount from the lower right reference position. Alternatively, the image forming apparatus is set to be separated by a length equal to the binding margin, and image formation is started. This allows
A preliminary scan is performed, and a document area is detected. As a result, the distance between the document and the reference position is calculated, and the erase amount or the binding margin is set.

According to a second image forming apparatus of the present invention, there is provided reading means for reading a document placed on a document table, and image data of the document read by the reading means being placed on the document table. Position detecting means for detecting the position of the document being read, mode setting means for setting an image forming mode based on the position of the document detected by the position detecting means, and image forming mode set by the mode setting means. Control means for controlling the image forming operation based on the That is, the mode setting means automatically sets the image forming mode based on the result of detecting the placement position of the document. For example, the mode setting means automatically sets a predetermined image forming mode when the document placement position detected by the position detection means is a predetermined position. For example, the predetermined position is outside a predetermined document detection range on the document table, and when a document is detected at this predetermined position, a predetermined image forming mode is set. The predetermined image forming mode is, for example, a book mode in which images of two portions on the left and right sides of a document are continuously formed.
The user places the document such that the center of the book document is aligned with the book reference position set on the platen and outside the normal document reading range. When image formation is started, preliminary scanning is performed, and a document area is detected. As a result, when it is recognized that the book document is set at the book reference position, the book mode is set.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. First, an overall configuration of a digital copying machine according to an embodiment of the present invention will be described. FIG. 1 is a sectional front view showing the entire configuration of the digital copying machine. In FIG. 1, a copier includes a scanning system 10 for reading a document and converting the image signal into an image signal, an image processing unit 20 for processing an image signal sent from the scanning system 10, and temporarily storing image data input from the image processing unit 20. Then, a rotary memory unit 30 that outputs to a printer device after performing an editing process, a print processing unit 40 that drives a semiconductor laser 61 based on image data output from the memory unit 30, and a laser beam from the semiconductor laser 61 is exposed. A laser optical system 60 for guiding an exposure position on the body drum 71, an image forming system 70 for developing a latent image by exposure, transferring the image onto recording paper, and fixing the image to form an image; Panel 90,
The image forming apparatus includes a document conveying unit 500 that conveys a document and reverses the front and back as necessary. Note that the reading unit is the scanning system 1
The printer unit is constituted by the print processing unit 40, the laser optical system 60, the image forming system 70, and the like.

The reading section reads an image of an original placed on the platen glass 19 and generates image data corresponding to each pixel of the image of the original. First scanner 11 having exposure lamp 12 and first mirror 13a and second scanner 1 having second and third mirrors 13b and 13c
4 is moved in the directions of arrows b and b '(sub-scanning direction) by driving the scan motor M2. The light of the exposure lamp 12 is reflected by the original on the platen glass 19,
Line sensor 1 via 3a, 13b, 13c and lens 15
7 is irradiated. The line sensor 17 has a large number of photoelectric conversion elements (CCDs) in a direction (main scanning direction) orthogonal to the paper surface of FIG.
Are read, an image is read at 400 DPI, and image data corresponding to each pixel is output. Further, as described above, when the first scanner 14 moves in the directions of the arrows b and b ′, the line sensor 17 can scan the document image. The sensor SE3 detects that the first scanner 11 is at the home position. The scan motor M2 moves the first and second scanners 11, 14 in the direction of arrow b at a higher speed than in the direction of arrow b '. That is, the scanning of the image by the line sensor 17 when the scanners 11 and 14 move in the direction of the arrow b is the preliminary scanning, and the position of the original on the platen is determined based on the image data output from the line sensor 17 at this time. Is detected. On the other hand, the scanning of the image by the line sensor 17 when the scanners 11 and 14 move in the direction of the arrow b 'is the main scanning. At this time, the original image is copied based on the image data output from the line sensor 17. Will be The image data output from the line sensor 17 is processed by the image processing unit 20 and then transmitted to the memory unit 30. The memory unit 30 includes the image processing unit 2
The image data received from 0 is temporarily stored and transmitted to the printer unit after the editing process or directly.

Next, the printer section will be described. The print processing unit 40 controls the laser optical system 60 based on the image data received from the memory unit 30. The laser optical system 60 emits a laser beam modulated (on / off) by the print processing unit 40 and emits a laser beam. The laser beam emitted from the semiconductor laser 61 is scanned on the photosensitive drum 71. Polygon mirror 62, fθ lens 63, mirror 64a,
64b and 64c. Around the photosensitive drum 71 that is rotationally driven in the direction of arrow c, along the rotational direction,
Charging charger 72, developing unit 73, transfer charger 7
4. A separation charger 75, a cleaner 76, and an eraser lamp 77 are arranged, and a toner image is formed by a well-known electrophotographic process, and is transferred onto a sheet. The paper is
The paper is supplied from paper feed cassettes 81a and 81b by paper feed rollers 82a and 82b, and is fed to a transfer charger 74 by a paper transport path 83 and a timing roller 84. The sheet on which the toner image has been transferred at the position of the transfer charger 74 is conveyed by a conveyor belt 85, a fixing device 86, and a discharge roller 87.
Is discharged onto the paper discharge tray through These various rollers and the photosensitive drum 71 are driven by a main motor M1. Further, near the paper feed cassettes 81a and 81b, paper size detection sensors SE1 and SE2 for detecting the size of the paper stored in each cassette are provided.

The document feeder 500 includes a document feed tray 51
The original set on the platen glass 19 is automatically
The document is conveyed upward, and the document read by the scanning system 10 is discharged to a document discharge unit 511. In the normal mode, one or a plurality of documents are set on the document feed tray 510 with the surface to be read facing upward, and the side regulating plate is adjusted to the width of the document. By doing so, the presence of a document on the document feed tray is detected by the empty sensor SE54. When the operation is started, the set originals are conveyed in order from the lowermost original by the paper feed roller 501, separated by the separating roller 502 and the separating pad 503, and fed one by one. The conveyed document passes through the intermediate roller 504, and after the registration sensor SE51 and the width size sensor SE53 detect the document,
The skew is corrected by the registration roller 505. Thereafter, the original is transferred to the registration roller 505 and the original transport belt 5.
In step 06, the document is conveyed over the platen glass 19, and immediately after the rear end of the document has passed the left end of the document scale 512, the document conveyance belt 506 and the registration roller 505 slightly reverse and stop. As a result, the right end of the original comes into contact with the edge of the original scale 512, and the original is placed on the platen glass 1.
9 is set to the correct position. At this time, the leading edge of the next document has reached the registration roller 505, so that the transport time of the next document is reduced. When the original is set at an accurate reading position on the platen glass 19, the scanning of the original by the scanning system 10 is performed. When the reading of the document is completed, the document is transported leftward by the document transport belt 506, the transport direction is changed by the reversing roller 507, and the document is discharged onto the discharge tray 511 after passing above the switching claw 508. In the case of a double-sided original, when reading of the first side is completed, the original is conveyed to the left by the original conveying belt 506, the conveying direction is changed by the reversing roller 507, and then sent out onto the platen glass 19 again by the switching claw 508. Then, the second side of the document is set at the reading position. The document whose second surface has been read is conveyed to the left by the document conveying belt 506, and is discharged onto a discharge tray 511 via a reversing roller 507, a switching claw 508, and a discharge roller 509. Further, the platen glass 19 of the document conveying belt 506 is used.
The side surface is colored orange. Thereby, the reflected light of the light of the exposure lamp 12 by the document conveying belt 506 is
For the line sensor 17, the color has a small spectral sensitivity. That is, for the line sensor 17, this is the same as the case where the document conveying belt 506 is black. Accordingly, since the background of the document is usually white, the line sensor 17 can identify the document and the lower surface of the document transport belt 506 even when the document transport belt 506 is closed. Further, even when the document conveying unit 500 is not closed, the reflected light of the document conveying belt 506 by the exposure lamp 12 does not reach the line sensor 17, so that the document area can be identified.

Next, the control circuit of the digital copying machine is shown in FIG.
This will be described with reference to FIG. The image processing unit 20 includes a CPU 21 for performing timing control of the entire apparatus, an A / D converter 22, a shading correction unit 23, a gradation correction unit 24,
Scaling unit 25, line buffer 26, binarization unit 2
7, an address decoder 28, and a document area detector 29. An image reading synchronization signal is supplied from the CPU 21 to the line sensor 17, the image processing unit 20, the memory unit 30, and the print processing unit 40. The signal input for each line from the line sensor 17 is analog data, and this analog data is A / D
The data is converted into digital image data of 8 bits per pixel by the converter 22, and shading correction is performed by the shading correction unit 23. Next, gradation correction such as MTF correction and γ correction is performed by the gradation correction unit 24, and scaling processing is performed by the scaling processing unit 25. The line buffer 26 stores the image data after the scaling process for one line, and sends the image data to the document area detection unit 29 when the scanners 11 and 14 move in the b direction (forward movement), and sends the image data to the b ′ direction. Also has a switching function for sending the image data to the binarization processing unit 27 when moving (returning).

The original area detecting section 29 is provided on the platen glass 19.
The upper document position is detected. Also, the binarization processing unit 27
After converting the bit image data into binary data by error diffusion processing, the data is transferred to an address in the memory unit 30 specified by the address decoder 28. The memory unit 30 has a capacity capable of storing 50 pages of A3 size originals. The image memory 31 for one page in it is 2
It is configured to have a dimensional address, and x in the sub-scanning direction.
The address and the y address are set in the main scanning direction. In the present image forming apparatus, since A3 original is read at 400 DPI, x is set from 0 to 6799, and y is set from 0 to 4799. A similar image memory is provided for another 49 pages. The image data written in the memory unit 30 is transmitted to the print processing unit 40 based on an instruction from the CPU 21.
Transferred to In the print processing unit 40, the received image data is converted into an analog image signal by the D / A converter 41, and based on the analog image data, the LD driver 42
Drives and controls the semiconductor laser 61. Also, the CPU 21
Also controls the input and display of signals from various operation keys on the operation panel 90.

Next, the operation panel 90 of the digital image forming apparatus will be described with reference to FIG. The operation panel 90 includes a liquid crystal touch panel 91, numeric keys 92 for inputting numbers such as the number of copies and a copy magnification, a clear key 93a for resetting the numbers and the like to a standard value "1", and set values set in the copying machine. Are provided with a panel reset key 93b for resetting to a standard value, a stop key 93c for stopping the copy operation, and a start key 96 for starting the copy operation. An AMS mode key 99 for selecting an automatic magnification setting mode (AMS mode), an erase mode key 94 for selecting an erase mode, a binding margin mode key 95 for selecting a binding margin mode, and an AMS mode are selected. There is also provided a display section 99a for displaying that the binding mode has been selected, a display section 94a for displaying that the erase mode has been selected, a display section 95a for displaying that the binding margin mode has been selected, and the like. Further, the operation panel 90 includes a copy mode such as a copy simplex mode, a copy duplex mode, and a simplex 2in.
1-mode, 2-sided 2-in-1 mode, 4-sided 1-in-1 mode,
A copy mode key 97 for selecting one of the two-sided 4-in-1 mode and the weekly magazine binding mode, and the copy mode selected and set is copy one-sided mode, copy-sided mode, single-sided 2-in-1 mode, double-sided 2-in-1 mode, single-sided 4-in-1 mode, and double-sided 4-in-1 mode. Mode and weekly magazine binding mode. (Nin
The one mode is a mode for forming an image by reducing N documents to one sheet. Further, an operation panel 90 has an original mode key 98 for selecting any one of the one-sided original mode, the two-sided original mode, and the book mode, a display section 98a for displaying that the selected and set original mode is the one-sided original mode, A display unit 98b for displaying that the original is in the duplex mode, and a display unit 98c for displaying that the book is in the book mode.
Etc. are provided. In addition, the liquid crystal touch panel 91
Displays the operating status of the copier, such as exposure level, copy magnification, recording paper size, etc., various abnormal status of the copier such as occurrence of jam, occurrence of serviceman call, occurrence of paper empty, and other information. Copy magnification,
An input for designating an automatic selection mode for recording paper or the like can be made.

Next, in the present digital image forming apparatus,
An outline of a copying operation under the control of the CPU 21 will be described with reference to a timing chart of FIG. When the start key 96 is pressed at time t ₀ , the scan motor M2 of the reading unit IR drives the scanners 11 and 14, and scanning of the original in the b direction (forward movement) is started. At the same time, when the exposure lamp 12 is turned on and the first scanner 11 is separated from the home position sensor SE3 (time t ₁ ), the line sensor 17 outputs an image signal. Then, to complete the b direction scanning of the original platen glass throughout (forward movement) of (time t _2), the scan motor M2 is braked for reversing the scan motor M2 is reversed at time t _4, original b ' Start scanning in the direction (backward movement). Note that the scanning speed is 16 times higher than in the backward movement for reading an image, since it is sufficient to know only the document placement area during the forward movement. Time t ₂ later, the document region detection unit 29 performs detection processing of the document placing area on the platen glass 19, at time t ₃ and the detection result is found. The scanning speed of the document is predetermined, and the time (t ₃ −t ₁ ) required for detecting the position of the document is also stored in the CPU 21. Therefore, the time t ₆ to the line sensor 17 during the backward scan reads a time t ₅ and a document tip read the document trailing edge, the detection result of the document placing area was found (time t ₃₎ at the same time turn out. Then, at time t ₅ to read the trailing edge of the document,
The output of the line sensor 17 is written to the image memory 31 after the above-described image processing. Thereafter, since the line sensor 17 at time t ₆ is the timing of reading the document trailing edge, of the original image data into the image memory 31 the write is completed.

[0015] At time t ₇ home position sensor SE3 is turned on again. Here, the brake for stopping the scan motor M2 is applied, the output of the line sensor 17 is stopped, and the exposure lamp 12 is turned off. And then
Writing of image data into the read image memory 31 of the original image is completed, the printer portion P is in the operating state at time t _8, the reading and image formation of image data from the image memory 31 is started at time t ₉ You. At such a timing, the document image is copied on the paper in accordance with the selected copy mode. In this digital image forming apparatus, as shown in FIG. 4, scanning is performed over the entire area of the platen glass 19 at the time of preliminary scanning (backward movement). That's why.

Next, detection of the document placement area will be described. FIG. 5 shows the configuration of the document area detection unit 29. During forward scanning of a document, the output from the line sensor 17 is temporarily stored in a line buffer 26 after image processing, and the image data from the line buffer 26
Are binarized by the binarization circuit 291 in the above. Since the binarization circuit 291 is for the purpose of detecting the document area, unlike the case of the binarization circuit 27 of the image processing unit 20, the simple binarization circuit 291 is used.
Value processing is being performed. The threshold value is higher than that of the binarization circuit 27, so that there is no erroneous detection even when there is a large area black image in the document image or when the binding portion of the book document is raised. Specifically, while the binarization circuit 291 determines that the density level of 256/256 to 200/256 is black, the binarization circuit 27 averages 256/256 to 128 / When the density level is 256, it is determined to be black. Also, at this time, regardless of the magnification designated by the copy magnification selection key 902, the scaling processing section 25 performs the same magnification processing based on the magnification signal from the CPU 21.

The image data binarized by the binarizing circuit 291 is stored in the area memory 292 of the document area detecting section 29 under the instruction of the address decoder 293 from the CPU 21. At this time, the CPU 21 processes the image data sequence in the main scanning direction in units of 2 bytes (16 pixels), but writes only one pixel of the most significant bit into the area memory 292. That is, the image data output from the line sensor at a resolution of 400 DPI has a resolution of 1 in the main scanning direction.
After being thinned out by the CPU 21 so as to be 1/6 (25 DPI), the data is stored in the area memory 292. Also,
Since the moving speed of the first scanner 11 at the time of the forward movement is increased to 16 times the moving speed at the time of the backward movement, the speed at which the line sensor 17 sub-scans the document image at the time of the forward movement is 16 times that at the time of the backward movement. On the other hand, since the reading of the line sensor 17 is performed under a reference clock having a constant period, the resolution of the image read by the line sensor 17 in the sub-scanning direction is 25 DPI, which is 1/16 of the backward movement when moving forward. Become. In this way, the area memory 292 stores image data at a low resolution (25 DPI) in both the main scanning direction and the sub-scanning direction. This is because the document area detection unit 29 only needs to know the document position, so that it is not necessary to recognize the image at high resolution, and the less the image data is, the shorter the time required for the image processing for detecting the document position is. That's why. The resolution is 25D
Since the pixel interval in an image that is a PI is about 1 mm,
In this embodiment, the position of the document can be detected in units of about 1 mm. Two-dimensional addresses of x and y are set in the area memory 292, and the image data stored therein reproduces the state on the platen glass 19. Area memory 2
A broken line at 92 indicates the position of the document represented by the two-dimensional address. In practice, the original is often placed slightly inclined. FIG. 5 shows a state in which the document is placed in a counterclockwise direction with broken lines, and FIG. 6 shows a state in which the document is placed in a clockwise direction with broken lines. In each of the states of FIGS. 5 and 6, the vertices of the four corners of the document are denoted by S, T, V, and U in order from the right on the X coordinate in the figure.

The system described above has various modes (book mode, binding margin mode, erase mode, automatic document size (AMS) mode, automatic paper size (APS) mode, and manual mode) described below.
As will be described later on the mode setting (FIG. 15), the book mode is set from the detected document placement position.
When the mode is not the book mode, the binding margin and the erase amount are set from the document placement position in accordance with the set editing mode (the binding margin mode and the erase mode). Further, according to the copy mode (automatic document size mode, automatic paper size mode, manual mode), the magnification, paper size, and selected paper size are determined from the detected document placement position.

First, the book mode will be described. In the book mode, as shown in FIG. 7, a book (book original) 100 is opened, placed on the original glass 19, and two pages are sequentially read and copied. Here, the book (book original) 100 is placed at the center of the upper side of the original glass, with the center aligned with the upper book reference position (triangular mark) 102. That is, the book is placed beyond the normal reading range indicated by the broken line 104 (partitioned by A3T in the horizontal direction and A4Y in the vertical direction). It should be noted that the central portion of the book is shown in a distinctive manner, schematically showing that the central portion of the book is dark. B5Y, B written on the original scale on the platen 19
Reference marks 5T, A4Y, A4T, B4T, and A3T are manuscript size indices with reference to the lower right corner of the manuscript table, where Y and T represent horizontal and vertical. When the copying operation is started, preliminary scanning is performed, and the document area is detected. When it is recognized that the document is set at the book reference position, the book mode is set. Then, an optimal sheet is set according to the document size obtained from the detected document area. After that, first, the A scan for scanning the right page (the left side in FIG. 7) of the book document 100 is performed, and then the B scan for scanning the left page (the right side in FIG. 7) of the book document 100 is performed. The image data thus obtained is sent to the printer unit P. As described above, the book mode is set by simply setting the document at the book reference position 102, and the image is formed by being divided into respective pages.

Next, the binding margin mode will be described. The binding margin mode is a binding margin mode key 9 on the operation panel 90.
5 is selected. In the binding margin mode, in order to add a binding margin to the read document image, the image position is shifted by the binding margin to reproduce the document image. As shown in FIG. 8, the A4Y original 110 is set on the original table 19 at a distance 116 equivalent to the desired binding margin 114 from the lower right reference position 112. When the copying operation is started, preliminary scanning is performed, and a document area (hatched portion) is detected, whereby the document 110 and the reference position 1 are detected.
Then, a distance 116 between them is calculated, and a binding margin 114 is set. Thereby, the binding margin 118 is set. Then, an optimal sheet is set according to the document size obtained from the detected document area. After that, the original image is fully scanned, and the obtained image data is sent to the printer unit P. Thus, the position of the document image is shifted or the document image is scaled to form an image in accordance with the binding margin 114 set according to the placement position of the document 110.

Next, the erase mode will be described.
The erase mode is selected by an erase mode key 94 on the operation panel 90. In the erase mode, when an erase amount on the right side in the image diagram is set, an image corresponding to the erase amount is erased. As shown in FIG. 8, an A4Y original (hatched portion) 120
Are set at a distance 126 from the lower right reference position 112 by a length 126 equivalent to the desired erase amount 124. When the copying operation is started, a preliminary scan is performed, and the original area is detected, whereby the distance 12 between the original and the reference position is determined.
6 is calculated, and the erase amount 124 is set. Then, an optimal sheet is set according to the document size obtained from the detected document area. After that, the original image is fully scanned, and the obtained image data is sent to the printer unit. In this manner, a portion 128 of the document image is erased according to the erase amount set based on the document placement position, and an image is formed.

Next, the automatic magnification size mode (AMS mode) will be described. In the AMS mode, the operation panel 9
0 is selected by the AMS mode key 99 above. FIG.
As shown at 0, the A4T original 130 is set with the lower left end aligned with the A3T index 132 on the original scale, and when the copying operation is started, first, a preliminary scan is performed, and the original area is detected. A3T indicated by the index 132 corresponding to the lower left end of the document is set as the paper size. Then, the copy magnification is calculated based on the document size obtained from the detected document area and the above-described paper size, and the read magnification is set. After that, the original image is fully scanned, and the obtained image data is sent to the printer unit. Thus, the A4T original 130 is enlarged to a desired A3T size to form an image.

Next, details of each operation mode are shown in FIGS.
Will be described with reference to the flowchart of FIG. FIG.
3 is an overall flowchart of the present system. First, initialization is performed (step # 11). Next, control processing of input signals of various switches from the operation panel 90 (step #)
12, see FIG. 12), document area detection (step # 13),
A mode setting process (step # 14) is performed. Next, an image input process (step # 15) is performed until the input of the image data is completed (NO in # 16). When the input of the image data is completed (YES in step # 16), an image data output process is performed (step # 17), and the process returns to step # 12.

FIG. 12 is a flowchart showing details of the input signal processing (FIG. 11, step # 12). First,
Erase mode key 9
The determination is made on the on-edge of No. 4 (step # 101). If it is determined that it is the on-edge, the lighting state of the display unit 94a indicating the selection of the erase mode is next determined (step #).
102), when the display unit 94a is lit,
a is turned off, and the erase mode is released (step # 10).
3). If the display section 94a is off, the display section 94a indicating the selection of the erase mode is turned on to set the erase mode (step # 104). Next, the selection setting state of the binding margin mode is determined by the on-edge of the binding margin mode key 95 (step # 105). Binding allowance mode key 9
If it is the on-edge of No. 5, then the lighting state of the display unit 95a indicating the selection of the binding margin mode is determined (step #).
106). When the display section 95a is lit, the display section 95
a is turned off, and the binding allowance mode is released (step # 10).
7). If the display section 95a is off (step # 1)
06, NO), display section 95a showing selection of binding margin mode
Is turned on to set the binding allowance mode (step # 10).
8). Next, the selection setting state of the AMS mode is determined by the ON edge of the AMS mode key 99 (step # 10).
9). If it is the ON edge of the AMS mode key 99, then the lighting state of the display unit 99a indicating the selection of the AMS mode is determined (step # 110). If the display unit 99a is on, the display unit 99a is turned off, and the AMS mode is canceled (step # 111). If the display unit 99a is off (NO in step # 110), the display unit 99a indicating selection of the AMS mode is turned on, and the AMS mode is set (step # 112). Next, it is determined whether or not the start key 96 on the operation panel for instructing the start of copying is pressed based on the on-edge of the start key 96 (step # 1).
13) If it is on-edge, a scan start request is output (step # 114).

FIGS. 13 and 14 are flowcharts of the processing for detecting the document position (FIG. 11, step # 13). First, the value of the x address of the area memory 292 is set to 0, and the variable F is initialized to 0 (step # 200). Then, the check is started from the line of x = 0. In step # 201, the number L (x) to L (x + 4) of white pixels in each of the five consecutive lines (the area memory 292 in FIG. 5)
L (x) is shown in FIG.
202 L (x) ~L (x + 4) is judged whether all larger than the predetermined value epsilon ₁ in. Note that ε ₁ and ε ₂ described below
The value of ～Ipushiron ₄ are both suitably about 2 mm. L (x)-L
(x + 4) is smaller than even epsilon ₁ in one of (NO at step # 202), L (x) ~L (x + 4) until greater than all epsilon _1, while incrementing the x (step #
203), and repeats the processing of steps # 201 to # 202. If L (x) ~L (x + 4) is larger than all epsilon _1, it determines that the vertex S of the original is detected, the vertex S x
Let the coordinate S _x be x and the y coordinate S _y be y (x) + L (x) / 2
(Step # 204). Note that y (x) is the minimum value of the y addresses of the continuous white pixels on the x-th line. As described above, by making the determination in units of five lines while increasing the value of x one by one, it is possible to prevent erroneous determination due to dust on the platen glass.

The next steps # 205 to # 207 are for judging the inclination of the original on the platen glass.
First, in step # 205, y (x) and y (x + 1) are compared. If the original is inclined clockwise (see FIG. 5B), y (x) is larger than y (x + 1) (YES in step # 205), and the variable F is set to 1 (step # 20).
6). On the other hand, when the document is tilted counterclockwise (see FIG. 5A), y (x) is smaller than y (x + 1) (NO in step # 205), and the variable F is set to 0 (step # 207).
That is, if the variable F is 1, it indicates that the document is tilted clockwise, and if the variable F is 0, it indicates that the document is tilted counterclockwise. Next, in steps # 208 to # 210, the vertex T is detected. First, comparing the difference in the number of white pixels of consecutive adjacent lines with a predetermined value epsilon ₂ (step #
208). Until the difference of the number of white pixels is smaller than epsilon ₂ (NO at step # 208), while incrementing the x (step # 209), the determination in step # 208 to the difference in the number of white pixels is less than epsilon ₂ repeat. When the difference in the number of white pixels of consecutive adjacent lines is smaller than epsilon ₂
(YES at step # 208), it is determined that the apex T of the original is detected, the x-coordinate T _x of the vertex T and x, y coordinates _{T y F · y + (1} -F) · (y + L (x)) (Step # 21
0).

Next, in steps # 211 to # 216, the vertex V is detected. First, while increasing the value of x by 3 until the difference in the number of consecutive white pixels of adjacent lines becomes smaller than −ε ₃ (step # 212),
Step 211 is repeated. By the way, since there are many lines between the vertex T on the front end side of the document and the vertex V on the rear end side, it is not determined whether each line is the vertex V of the document. It takes too long. At this time, since there is almost no influence of dust on the platen glass, it is desirable to increase the overall detection speed even if accuracy is somewhat sacrificed. Therefore, step # 2
In step 12, the value of x is increased by 3 to detect whether or not the document is at the rear end every three lines. First, when the difference in the number of white pixels of consecutive adjacent lines is less than-epsilon ₃ (YES in Step # 211), and returns a value of 2 x (Step # 213). This is the judgment of step # 211
Since it is line by line, the determination in step # 211 is YES
This is because there is a possibility that the value at the time of may jump over the x coordinate of the true vertex. Then, step # 211
The same determination as the difference between the number of white pixels of adjacent lines-epsilon ₃
It repeats while increasing x by 1 until it becomes smaller (steps # 214 to # 215). When the difference in the number of white pixels of consecutive adjacent lines is less than-epsilon ₃ (step # 214
YES), it is determined that the vertex V of the document has been detected, the x coordinate V _x of the vertex V is set to x, and the y coordinate V _{y is set} to (1−F) · y + F ·
(y + L (x)) (step # 216).

Subsequently, the detection of the vertex U is performed in the same procedure as the detection of the vertex S. That is, until the number of white pixels contiguous in adjacent five lines L (x) ~L (x + 4) is less than all epsilon _4, while incrementing the x, step # 21
8 is repeated. If L (x) ~L (x + 4) is less than all epsilon _4, determines that the vertices U of the original is detected, the x-coordinate U _x of vertices U and x, y coordinates U _y y (x) + L ( x) /
2 (step # 220). The coordinates of the vertices S, T, U, and V of the document are obtained as described above, and the position where the document is placed and the size of the document can be determined from the coordinates of these vertices. Thereafter, the document placement position and document size are calculated from the coordinates of the vertices, the mode is set, the document image is fully scanned, and the obtained image data is output to the printer unit.

Hereinafter, control at the time of mode setting will be sequentially described. FIGS. 15 and 16 show control for setting a mode based on vertex coordinates obtained by document area detection (FIG. 1).
1 is a flowchart of step # 14). First,
A coordinate conversion is performed (step # 300). That is, since the coordinate values of the detected document vertices S, T, U, and V are indicated using the x and y addresses of the area memory 292, they are converted to the XY coordinate system of the image memory 31. As described above, an X address is set in the sub-scanning direction and a Y address is set in the main scanning direction in the image memory 31, and the range of X and Y is set according to the following equations (1a) and (1b). ing. 0 ≦ X ≦ 6799 (= X ₀ ) (1a) 0 ≦ Y ≦ 4799 (= Y ₀ ) (1b) The area memory 292 is 1/16 of the image memory 31
In step # 300, the coordinate system is converted based on the following equations (2a) and (2b). X = 16x (2a) Y = 16y (2b)

Next, the original vertex S, converted into the XY coordinates,
The coordinates of T, U, and V are read (step # 301), and based on these, the vertices S '( _S'x , _S'y ), T' ( _T'x ,
The coordinates of T ′ _y ), U ′ (U ′ _x , U ′ _y ), and V ′ (V ′ _x , V ′ _y ) are determined according to the following equations (3a) to (3h) (step # 30).
2). As a result, an appropriate position can be determined even when a document is placed obliquely. S ' _x = (S _x + T _x ) / 2 (3a) S' _y = (S _y + V _y ) / 2 (3b) T ' _x = (S _x + T _x ) / 2 (3c) T' _y = ( _{U y + T y) / 2} (3d) U 'x = (U x + V x) / 2 (3e) U' y = (U y + T y) / 2 (3f) V 'x = (U x + V x) / 2 (3g) V ' _y = (S _y + V _y ) / 2 (3h) Then, the length (the length in the sub-scanning direction) D _x and the width (the length in the main scanning direction) D _y of the document are calculated. It is determined by the following equations (4a) and (4b) (step # 303). D _x = (S ′ _x + T ′ _x −U ′ _x −V ′ _x ) / 2 (4a) D _y = (T ′ _y + U ′ _y −S ′ _y −V ′ _y ) / 2 (4b)

Next, whether the book mode is set or not is determined based on the document placement position. First, it is determined in which direction the document is inclined (step # 304). In result of the step # 304, since if tilted clockwise is set a reference position of the book original as shown in FIG. 9, S _y and V _y are both read range A3 (BK
It is determined whether or not the number is outside the range (1) (step # 30)
5). Further, in the results of step # 304, it is determined whether the case is tilted counterclockwise is outside the likewise T _y and U _y are both A3 of the reading range and the step # 305 (BK1) (step # 306 ). Step # 305
If the determination in steps 306 and 306 is YES, the book mode is set (step # 307). Step # 305
If the determination in steps 306 and 306 is NO, it is next determined whether the edit mode (binding margin, erase) has been set (step # 308). If it is determined that the binding margin mode is set, set S ′ _x to the binding margin amount
(Step # 309). Further, in the judgment of step # 308, if the erase mode is determined to be set as in step # 309, it sets the S _'x to erase amount (Step # 310).

Next, the copy mode set by the AMS mode key 99 is determined (step # 311).
When it is determined that the automatic magnification setting (AMS) mode is not set and the manual mode or the automatic paper selection mode (APS) is set, the set magnification M is read (step # 312). If it is determined in step # 313 that the manual mode has been selected, the length (length in the sub-scanning direction) _Px and the width (length in the main scanning direction) Px of the selected sheet are determined. read _y
(Step # 316). On the other hand, if it is determined in step # 313 that the APS mode has been selected, the necessary paper is set based on the document sizes D _x and D _y determined in step # 303 and the set magnification M. Size P _x , P
_y is calculated according to equations (5a) and (5b) (step # 3).
14). _{P x = M · D x (} 5a) P y = M · D y (5b) Next, the sheet was determined size P _x, sheet feeding port is selected for paper perfect size P _y is set (Step # 315). If there is no paper feed port in which appropriate paper is set, a warning may be displayed on the operation panel 90.

In the determination at step # 311, the AMS
If it is determined that the mode is selected, the paper sizes _Px and _Py are set based on the result of the document area detection (step # 319, see FIG. 17). Then, the document sizes D _x and D _y determined in step # 303 and the
Paper size P _x determined in 319, based on the P _y, calculates an optimum copy magnification M in accordance with the following equation (6), CPU 21
(Step # 320). M = min (P _x / D _x , P _y / D _y ) (6) Here, min (a, b) means the smaller of a and b. By the above processing, the paper selection in the AMS mode is
The setting can be made simply by setting the original in accordance with the index of the desired size of the platen glass. Also, regardless of which mode of APS, AMS or manual is selected,
The document sizes _Px and _Py , the magnification M, and the paper sizes _Dx and _Dy are determined.

Next, the CPU 21 issues an instruction to the scaling unit 25 so that the reading magnification becomes M (step # 317). Then, the original reading range of the line sensor 17 in the sub-scanning direction, that is, t ₅ and t ₆ in the timing chart of FIG. 4 are set according to the following equations (7a) and (7b) (step # 318). _{t 5 = -V 'x / Vb} ' + t 1 + Const (7a) t 6 = -S 'x / Vb' + t 1 + Const (7b) here, Vb 'is the moving speed (scanning speed during return movement of the scanner 11 ), And Const is a unique constant determined by the characteristics of the scanners 11 and 14 and the scan motor M2.

Next, FIG. 17 is a flowchart of the control for setting the paper size in the AMS mode (FIG. 16, step # 319). Referring to FIG. 6 and Table 1, first,
X-coordinate V _'x of the lower left vertex of the document to determine how many (Step # 350), according to Table 1, set the desired paper size P _x, the P _y. For example, when a document is set as shown in FIG. 6, V ′ _x is about 6720, the sheet size is determined to be A3T from Table 1, and P _x = 420,
P _y = 297 is set. Similarly, B4T, A4T, B5T, A5
T, B6T, etc. are set (steps # 351 to # 35)
6).

[0036]

[Table 1]

FIG. 18 is a flowchart of the image input process (FIG. 11, step # 15). First, it is determined whether the book mode is set (step # 40).
0). If book mode is set, then
It is determined whether the A-scan has been completed (Step # 4)
01). If the A-scan has not been completed, the reading range of the sub-scan A-scan is set based on the result of document area detection (step # 402). If the A-scan has been completed (YE in step # 401)
S), the reading range of the sub-scanning B scan is set based on the result of document area detection (step # 403). Foregoing setting is made to the time t ₃ of the timing chart of FIG. Then, by driving the scanning motor M2 at time t _4, first, to start the backward movement of the second scanner 11, 14 (Step # 404). At step # 405, and compares the current time and the time t _5, t _6. Since time is first scanner 11 if prior to t ₅ is out of read range, becomes the decision NO in step # 405, step # 408 to determine whether the backward movement has been completed by the home position sensor SE3 The determination is also NO, and step # 40
Return to 4.

[0038] from the time t ₅ the t ₆ becomes YES is determined in step # 405, the flow proceeds to step # 406. The image data output from the line sensor 17 in step # 406 is subjected to image processing for each line in the main scanning direction, and is then developed on the image memory 31 (step # 407). The image data at this time is sequentially written on the image memory 31 based on Y = 0 in the main scanning direction and on the basis of X = 0 in the sub-scanning direction. Past the time t _6, but the determination of step # 405 since the first scanner 11 exceeds the range reading is NO, a step # 408
The scan motor M2 continues to be driven until the home position sensor SE3 detects the completion of the return movement. When the home position sensor SE3 detects the completion of the return movement (at time t
₇ ), the determination in step # 408 becomes YES, and the scan motor M2 is braked and stopped (step ##
409).

Next, the data of the image corresponding to the area outside the original placing area is deleted (step # 410). This means that 0 ≦ X ≦
V ′ _x , S′x ≦ X ≦ X ₀ , 0 ≦ Y ≦ V ′ _y , or U ′ _y ≦ Y
This is a process of setting image data at an address satisfying ≦ Y ₀ to 0. By erasing the image data outside the document placement area, it is possible to prevent the document cover 50 from being copied in a solid black shape on the paper. The same effect is obtained when copying is performed without closing the document cover 50. next,
Only image data inside a rectangular area having a size corresponding to the determined paper size, centered on the midpoint of S ', T', U ', V', is output to the printer. For this purpose, first, the X coordinates Xf ₁ , Xf ₂ of the X-direction end of the rectangular area and the Y coordinates Yf ₁ , Yf ₂ of the Y-direction end are obtained according to the equations (8a) to (8d). Then, only the image data of the addresses satisfying both Xf ₁ ≦ X ≦ Xf ₂ and Yf ₁ ≦ Y ≦ Yf ₂ are represented by X = Xf ₁ , X
= Xf ₁ +1... In order. As described above, in step # 411, the image memory 31 of the image data
The timing to start reading from is t ₉ shown in the timing chart of FIG.

As described above, in the present embodiment, the document placement area is detected, the document image is read, and the read document image is subjected to the processing according to the copy mode.
Image data is output to the printer unit. The printer unit performs a process according to the received image data, and outputs the image data to the printer unit. The printer unit receives the received image data and edit mode (erase,
A document image is formed on a sheet according to a binding margin. In the above embodiment, the number of sheets, density, and copy mode (one side,
By providing an index indicating each mode such as double-sided, 2-in-1 and the like, and finishing mode (non-sort, sort, staple, etc.), various modes can be set. Also,
An index indicating the composite mode set by the user may be provided for each scale.

[0041]

According to the present invention, the setting of the copy mode requiring a complicated operation can be easily set by detecting the document placement position on the document table.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating the overall configuration of a digital copying machine.

FIG. 2 is a block diagram of a control system.

FIG. 3 is a plan view of an operation panel.

FIG. 4 is a sequence diagram of a copying operation.

FIG. 5 is a diagram illustrating a configuration of a document area detection unit.

FIG. 6 is a view showing a document on a document table.

FIG. 7 is a view showing a document placement state in a book mode.

FIG. 8 is a diagram showing a state of placing a document in a binding margin mode.

FIG. 9 is a diagram showing a document placement state in an erase mode.

FIG. 10 is a diagram showing a document placement state in an automatic magnification setting mode.

FIG. 11 is a main flowchart of control of the copying machine.

FIG. 12 is a flowchart of an input process.

FIG. 13 is a flowchart of a part of processing of document area detection.

FIG. 14 is a flowchart of a part of processing of document area detection.

FIG. 15 is a flowchart of a part of a mode setting process.

FIG. 16 is a flowchart of a part of a mode setting process.

FIG. 17 is a flowchart of a paper size setting process.

FIG. 18 is a flowchart of an image input process.

[Explanation of symbols]

19 platen, 20 image processing unit, 21 C
PU, 29 document area detection unit, 90 operation panel,
94 Erase key, 95 Binding key, 98 Original mode key, 99 Automatic magnification setting mode key.

Claims (10)

[Claims] A reading unit configured to read a document placed on a platen; and a position detection unit configured to detect a position of the document placed on the platen based on image data of the document read by the reading unit. Means, a mode selecting means for selecting a predetermined image forming mode, an image forming condition setting means for setting image forming conditions based on the position of the document detected by the position detecting means, and the image forming mode selecting means And a control unit for controlling a copying operation based on the image forming condition set by the image forming condition setting unit in the image forming mode selected by the control unit. 2. The image forming apparatus according to claim 1, wherein the image forming condition setting unit includes: a predetermined position on a document table;
An image forming apparatus, wherein an image forming condition is set based on a distance from a position of a predetermined portion of a document detected by the position detecting means. 3. The image forming apparatus according to claim 2, wherein the predetermined image forming mode is an automatic magnification setting mode, the image forming condition is a sheet size, and the predetermined The position of the portion is a position of a portion farthest from the predetermined position on the document table, and the image forming condition setting means is configured to determine a predetermined position on the document table and a predetermined portion of the document detected by the position detection means. An image forming apparatus comprising: determining a paper size based on a distance from a position; and automatically setting a magnification of an output image based on the position of the document and the paper size detected by the position detection unit. 4. The image forming apparatus according to claim 1, wherein the image forming condition setting unit includes: a predetermined position on a document table;
An image forming apparatus, wherein an image forming condition is set based on a distance from a document detected by the position detecting means. 5. The image forming apparatus according to claim 4, wherein the predetermined image forming mode is an erase mode,
An image forming apparatus according to claim 1, wherein said image forming condition is an erase amount indicating a range in which an image is erased during image formation. 6. The image forming apparatus according to claim 4, wherein the predetermined copy mode is a binding margin mode, and the image forming condition is a length for shifting a position of an image during image formation. An image forming apparatus characterized in that the binding margin represents a binding margin. 7. A reading device for reading a document placed on a platen, and position detection for detecting a position of the document placed on the platen based on image data of the document read by the reading unit. Means, a mode setting means for setting an image forming mode based on the position of the document detected by the position detecting means, and controlling an image forming operation based on the image forming mode set by the mode setting means. An image forming apparatus, comprising: a control unit. 8. The image forming apparatus according to claim 7, wherein the mode setting unit sets a predetermined image forming mode when the document placement position detected by the position detection unit is a predetermined position. An image forming apparatus characterized by automatically setting. 9. The image forming apparatus according to claim 8, wherein the predetermined position is outside a predetermined document detection range on a document table. 10. The image forming apparatus according to claim 8, wherein the image forming mode is a book mode in which images of two portions on the left and right sides of the document are continuously formed. Forming equipment.