JPH09312735A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To complete the image processing in a shorter time independently of a direction of an original by providing an image rotating means capable of rotating an image of an original read by an image read means. SOLUTION: This device is provided with an image rotation means 51 that rotates an image of an original read by an image read means 50 by 90 deg.. For example, an image rotating function is provided to, e.g. a page memory. An image rotation control means 55 controls rotation/non-rotation of the image rotation means 51 corresponding to number of processing recognized by a sheet number recognition means 54 prior to image forming by an image forming means 52 when a short side of the original is set in parallel with the main scanning direction of the image read means 50, that is, the original is set longitudinally on an original platen. Concretely the processing number recognized by the sheet number recognition means 54 is compared with a prescribed reference number and when the processing number is more than the reference number, the image rotation means 51 rotates the image of the original by 90 deg..

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 such as a copying machine which reads an image of a document and forms an image based on the image of the document.

[0002]

2. Description of the Related Art In this type of image forming apparatus, when a document is set on a document table and a copy operation is started, copy paper is selected based on the size of the document and a designated copy magnification. ing. For example, even if the original size is the same A4 size, if the designated magnification is the same size (100%), A4 size copy paper is selected and the designated magnification is 86.
In the case of%, B5 size copy paper is selected.

In general, the orientation of the original placed on the original table is the vertical orientation in which the short side of the original is parallel to the main scanning direction during image reading, and the long side of the original with respect to the main scanning direction. There are two horizontal patterns with the sides parallel. In addition, the orientation of the copy paper set in the paper feed cassette is either vertical, in which the long side of the paper is parallel to the paper transport direction, or horizontal, in which the short side of the paper is parallel to the paper transport direction. There are two patterns. Especially, copy paper set in the former direction is SEF (Short Edg.
The e-feed) paper is called, and the copy paper set in the latter direction is called LEF (Long Edge Feed) paper. Then, SEF paper is selected for the original set in the portrait orientation, and LEF is selected for the original set in the horizontal orientation.
Paper is selected.

[0004]

By the way, when comparing a series of processing times from the start of reading an image of an original to the end of the image forming operation by the difference in the orientation of the original, when the original is set in the horizontal direction, that is, The processing time is shorter when LEF paper is selected. This is because the reading length in the sub-scanning direction (the direction orthogonal to the main scanning direction) during image reading becomes shorter when the document is set sideways, and when the LEF paper is used, the reading length of the paper in the paper conveyance direction becomes smaller. This is because the length is shortened. Especially when the number of processed images is increased, the total length of multiple sheets that are continuously conveyed through the specified sheet gap is shortened. Processing time will also be shortened. Therefore, as the number of processed sheets increases, the difference in the processing time caused by the difference in the orientation of the original becomes larger. However, conventionally, even when the number of processed sheets reaches tens (for example, 20 sheets or more), the copying operation is started without paying attention to the orientation of the original, and as a result, the SEF sheet that takes time is selected. was there. Then, there is a possibility that the waiting time for other copying work becomes long and the daily work is hindered.

The present invention has been made to solve the above problems, and an object of the present invention is to form an image forming apparatus capable of completing an image forming process in a shorter time regardless of the orientation of a document. To provide.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and is an image reading unit for reading an original image by scanning an original set in a predetermined direction, and an image reading unit. In an image forming apparatus having an image forming unit for forming an image based on a document image read by the document reading unit, the number recognition unit for recognizing the number of processed images to be image-formed and the document image read by the image reading unit If the short side of the document is set parallel to the main scanning direction of the image reading means and the image rotating means capable of rotating, the number of processed sheets recognized by the number-of-sheets recognizing means prior to image formation by the image forming means. And a predetermined reference number of sheets, and when the number of processed sheets is larger than the reference number of sheets, an image rotation control means for rotating the original image by 90 degrees by the image rotating means is provided. It is use.

In the image forming apparatus of the present invention, when the short side of the document is set parallel to the main scanning direction of the image reading means, the number of processed sheets recognized by the sheet number recognizing means and the predetermined reference number of sheets are set. The image rotation control means compares.
At this time, when the number of processed sheets is larger than the reference number, the image rotation control unit gives the image rotation unit an instruction to rotate the original image. As a result, the image rotating means rotates the original image read by the image reading means by 90 degrees, and the image forming means forms an image based on the rotated original image. As a result, even when the original is set in the portrait orientation, the LEF paper is automatically selected as the copy paper when the number of processed sheets exceeds the reference number.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention when applied to, for example, a copying machine will be described below in detail with reference to the drawings. The present invention is not limited to application to a copying machine, and is applied to all image forming apparatuses that read an image of a document set in a predetermined direction and form an image based on the read document image. It is possible.

FIG. 1 is a schematic diagram showing the basic structure of the entire copying machine to which the present invention is applied. The copying machine 1 shown in the figure mainly includes a document 2 set on a document table such as a platen glass.
Image reading unit 4 for reading the image of the image with the CCD sensor 3,
The image reading unit 4 includes an image processing unit 5 for processing an image signal of the original 2 and a photoconductor 6 for charging, exposing, developing, and transferring, and an image output unit 7 having a sheet conveying system. There is.

The photosensitive member 6 incorporated in the image output section 7 is
After being uniformly charged by the charger 8, the laser beam scanner 9 scans the laser beam which is turned on and off according to the image signal whose pulse width is modulated, thereby forming an electrostatic latent image on the surface. . The photoconductor 6 on which the electrostatic latent image is formed is developed by the developing device 10, and the toner image obtained by this is transferred to the transfer preliminary charger 11 and the transfer charger 1.
2 is transferred to the sheet 13. The sheet 13 on which the toner image has been transferred in this way is separated by the peeling charger 14 from the photosensitive member 6
After being separated from the sheet, the sheet is conveyed to the fixing device 16 by the sheet conveying device 15, where the image is fixed and discharged to the copy receiver 17.

On the other hand, in addition to the above-described components, a cleaner 18 for removing the residual toner after the transfer by the transfer charger 12 from the photoreceptor 6 and a charger 8 around the photoreceptor 6.
A pre-exposure device 19 that exposes the photoconductor 6 is arranged so that the charging by the can is performed uniformly. Further, the sheets 13 to be copied are the paper feed cassettes 20a to 20h arranged in multiple stages.
They are stored in a stacked state in 20d and are fed from these paper feed cassettes 20a to 20d to paper transport rollers 21a to 21j.
The toner image on the photoconductor 6 is transferred by. Further, an automatic document feeder 22 is installed on the upper part of the copying machine 1. The automatic document feeder 22 automatically supplies a document to a document table which is an image reading position, and automatically discharges a document that has been read from the document table.

FIG. 2 is a block diagram showing the basic construction of the image processing system of the copying machine to which the present invention is applied. In the image processing system shown in the figure, reference numeral 30 is a C that optically reads an image of the original 31 and sequentially outputs a read signal in pixel units.
A CD sensor 32 is an analog signal processing unit that buffers and amplifies the analog signal read by the CCD sensor 30,
Reference numeral 33 is an A / D conversion unit that converts the analog signal into a digital signal after clamping and sample-holding, 34 is a shading correction (SD) unit that corrects the light amount of the optical system and element variation of the CCD sensor 30, and 35 is the original document 31.
A / E unit for removing the density of the background portion of the image, 36 is an enlargement / reduction unit for performing the enlargement / reduction and the density interpolation processing accompanied therewith, 3
7 is edge enhancement in a character image, halftone dot removal in a halftone image,
A digital filter (DF) unit for performing processing such as smoothing on a photographic image, 38 is an image editing unit for processing characters, extracting / deleting images, processing such as stamping and shading, 39
Is a CPU that controls all of them.

On the other hand, reference numeral 40 is a gradation correction unit for performing density reproducibility and data conversion at the time of density adjustment, and 41 is 8 bits, 2
An error diffusion processing unit for converting image data of 56 gradations into image data of 1 to 3 bits, 256 gradations, 42 is a page memory for recording the image data, and performing an image rotation process when necessary at the time of reading, 43 Is a selector (SEL) for selecting whether to output a copy at the same time as reading an image or to output a copy with the image data read from the page memory 42.
4 is a buffer memory that absorbs the difference between various image processing clocks before and after that, 45 is 1
Pulse width modulation (PWM) unit for generating a pulse width modulation signal from image data of 3 bits, 256 gradations, 46 is laser beam modulation and raster scanning by the pulse width modulation signal generated by the pulse width modulation unit 45 Image writing (ROS) for forming an electrostatic latent image on the photoconductor 47
Reference numeral 48 denotes a CPU that controls all of these.

FIG. 3 is a functional block diagram showing the main structure of the copying machine to which the present invention is applied. In FIG. 3, the image reading means 50 reads the image of the original by scanning the original set on the original table in a predetermined direction. The image is read from the above-mentioned CCD sensor or the original on the CCD sensor. It is composed of an optical scanning system for forming a reflected light image and the above-mentioned various image processing systems.

The image rotating means 51 is the image reading means 5 described above.
The original image read by 0 can be rotated by 90 degrees, and in the present embodiment, the page memory (see FIG. 2) described above has an image rotating function. By the way, the image rotation direction of the image rotation means 51 is as follows.
It only needs to have a function that can rotate 90 degrees in at least one direction, but considering the support for double-sided copying, etc., the rotation directions are +90 degrees and -90 degrees so that the images are not reversed on the front and back sides of copy paper. It is preferable to have a bidirectionality of degrees (or +270 degrees) and a function of rotating 180 degrees as a rotation angle.

The image forming means 52 is the image reading means 5 described above.
An image is formed on the basis of the original image read by 0, which is composed of the above-mentioned image writing section by laser scanning, the photoconductor and its peripheral equipment. The paper transport means 53 is for transporting the paper stored in the paper feed cassette toward the image forming means 52 as described above, and for discharging the paper on which the image is formed out of the machine. It is composed of a sheet conveying roller, a sheet conveying belt, and the like. Number recognition means 54
Is for recognizing the number of sheets to be processed by the image forming means 52, and recognizes the number of sheets to be processed from the information on the number of copies which is instructed via the operation panel of the copying machine.

The image rotation control means 55, when the short side of the document is set parallel to the main scanning direction of the image reading means 50, that is, when the document is set vertically on the document table, Prior to the image formation by the image forming means 52, the rotation / non-rotation by the image rotating means 51 is controlled according to the number of processed sheets recognized by the number-of-sheets recognizing means 54. Specifically, the number of processed sheets recognized by the number-of-sheets recognizing means 54 is compared with a predetermined reference number (described later), and when the number of processed sheets is larger than the reference number, the image rotating means 51 rotates the original image by 90 degrees. To do so, a control signal for processing execution is output to the image rotation means 51.

More specifically, the image rotation control means 55.
Is provided with a calculation unit 56 for calculating the reference number described above, and a comparison / control unit 57 for comparing / controlling the reference number obtained by the calculation unit 56 and the number of processed numbers recognized by the number recognizing unit 54. The rotation / non-rotation control signal for the rotation means 51 is output from the comparison / control unit 57. The paper size recognition unit 58 determines the size (including orientation) of the paper to be copied from the paper size input from the operation panel of the copying machine and the paper size information selected by the automatic paper selection function. To recognize. Incidentally, in the paper transport means 53, the image rotation control means 55
On the basis of the rotation / non-rotation control signal from the paper and the paper size recognized by the paper size recognition means 58, the paper to be copied and the paper feed cassette in which the paper is stored are specified.

Now, a method of calculating the reference number of sheets in the arithmetic unit 56 will be described. First, the reference number is "J", the process speed (mm / sec) is "S",
Time (sec) from the start of copying operation to the start of image transfer to the first sheet when rotating the original image
Is "Ta", and when the original image is not rotated, the time (sec) from the start of the copying operation to the start of image transfer to the first sheet is "Tb", the long side dimension of the sheet (copy sheet) (Mm) is "La", short side dimension (mm) is "Lb"
In such a case, the calculation unit 56 calculates “J”, which is the reference number, by the following formula 1. J = S · (Ta−Tb) / (La−Lb) ... Equation 1

In the equation (1), the process speed "S" is the conveying speed of the paper at the time of image transfer, and this is known information determined by the specifications of the copying machine together with the times "Ta" and "Tb". Is. Further, in “Ta”, the detection time of the document size, the reading time of the document image, the image recording time to the page memory,
It includes a transport time for transporting the first sheet of paper from the paper feed cassette to the image transfer position, and control and processing time required between these operations. Of these, the reading time of the original image and the image recording time to the page memory are not included in “Tb”. This is because when it is not necessary to rotate the document image, the image recording to the page memory and the image transfer to the copy sheet are performed simultaneously with the reading of the document image. Therefore,
From these differences (Ta-Tb), the time loss when rotating the document image is obtained. Further, the long-side dimension “La” and the short-side dimension “Lb” of the sheet are information obtained from the sheet size recognized by the sheet size recognizing unit 58, and from the difference (La−Lb) between them,
The length reduction amount per sheet with respect to the sheet conveyance direction is obtained.

From the above, the reference number "J" is used when the document is set in the portrait orientation on the document table (image reading means 5).
When the short side of the document is set parallel to the main scanning direction of 0), the time loss caused by rotating the document image is eliminated by performing image formation on a number of sheets, and the total is eliminated. The number of sheets indicates whether the processing time can be shortened, that is, the number of sheets that can be compensated for the time loss when the document image is rotated. It is set as a comparison standard.

Next, the rotation processing of the original image by the image rotating means 51 will be described. FIG. 4 is a block diagram showing the internal configuration of a page memory having an image rotation function. In FIG. 4, reference numeral 60 is a memory (RAM) in which image data is recorded, 61 is a memory controller for controlling writing / reading of image data with respect to the memory 60, 6
Reference numeral 2 denotes a CPU for setting / writing image data to / from the memory controller 61, a rotation mode, and setting a write / read address, a write / read area, and the like.

The memory controller 61 also includes an address controller 63, a data controller 64, and a C
It is configured by the PU interface 65. Of these, the address controller 63 is the CPU 62 to the C
Information on the writing / reading and rotation modes, the number of pixels in the main scanning direction, the writing / reading start address, the writing / reading area, which is given via the PU interface 65, and the writing / reading to / from the memory 60 by the synchronization signal input from the outside The read address is generated and output. The data controller 64 also performs buffer control when switching the direction of write / read image data for the memory 60.

Next, a specific image rotation process will be described with reference to FIG. 5 together with the relationship between pixel coordinates of image data and memory addresses. First, the image data has n pixels in the main scanning direction as one line, and this is read by m lines in the sub scanning direction. The reading order of pixels, that is, the flow of image data is 0, 1, 2, 3, ... N-1 for one line from the origin in the figure in the main scanning direction, and then n, n + 1, n + 2. ... and so on, and the final read pixel becomes mn-1. If these image data are recorded in the memory 60 in the order of reading, the number of each pixel becomes the memory address. That is, image data (pixel value) is recorded one by one corresponding to the memory address indicated by each pixel number. Therefore, when the image data recorded in the memory 60 is read out without being rotated, the memory addresses may be incremented in the order of recording.

On the other hand, in the case of rotating the image data by 90 degrees, 2n in the direction of arrow A from the starting point of n-1 pixel in the figure.
-1,3n-1, ..., mn-1 and one line are read, then n-2, 2n-2 ,. Image data is read out, and finally (m-1) n pixels are read out. The address generation at this time is performed by the CPU 6 in the address controller 63.
A value obtained by multiplying the number n of pixels in the main scanning direction given from 2 by 1 times, 2 times, 3 times, etc. for each pixel by a multiplier or an adder is obtained, and from this, "-1" in the first line, Two
It is performed by setting "-2" in the line 3 and "-3" in the line 3.

By the way, when the image is rotated in the opposite direction even when rotated by 90 degrees (when the image is rotated by 270 degrees), (m-1) n pixels in the figure are sequentially read out in the direction of the arrow B from the starting point to 180 points. In the case of the degree rotation, it is performed by sequentially reading in the direction of arrow C from the starting point mn-1 in the figure. Regarding the method of generating the address in the image rotation processing, various modified examples are conceivable, such as directly controlling the memory address using a counter or controlling the address using a counter and a table.

Next, the processing procedure of the copying machine to which the present invention is applied will be described with reference to the flowchart of FIG.
First, prior to the copy operation, a document is set on the document table in a predetermined direction, and copy conditions such as the number of copies and copy magnification are input via the operation panel (step S1). At this time, the number-of-processes (K) to be image-formed is recognized by the number-of-copies recognizing unit 54 from the input number of copies.

Next, the size of the document set on the document table is detected (step S2). This document size detection is performed by a plurality of sensors provided under the document table and optical scanning of the image reading means 50. Further, here, the size of the original document and whether the original document is set in the vertical or horizontal direction are detected. Further, the paper size recognition unit 58 recognizes the size of the paper to be copied according to the previously input copy magnification.

Subsequently, it is judged whether the document is oriented vertically, that is, whether the shorter side of the document is set parallel to the main scanning direction of the image reading means 50 (step S3). Here, when it is determined that the orientation of the original is landscape, LEF paper of a size corresponding to the previously input copy magnification (the short side of the paper is set to be parallel to the paper transport direction). The copy sheet is selected (step S4), and the image forming process is executed by the image forming means 52 (step S5). The image forming process in this case is performed simultaneously with the reading of the original image by the image reading means 50.

On the other hand, when it is determined that the document is oriented vertically, the arithmetic unit 56 of the image rotation control means 55 calculates the reference number (J) according to the above equation 1 (step S6). ), The standard number of sheets (J) obtained here
And the number of processed sheets (K) recognized by the sheet number recognition means 54 are compared (step S7). When it is determined that the number of processed sheets (K) is smaller than the reference number of sheets (J), SEF paper of a size corresponding to the previously input copy magnification (the long side of the paper is parallel to the paper transport direction). The copy paper set so that the image forming means 52 is selected (step S8), and the image forming process is directly executed by the image forming means 52 (step S5). The image forming process in this case is also performed simultaneously with the reading of the document image.

On the other hand, when it is determined that the number of processed sheets (K) is larger than the reference number of sheets (J), the image reading means 50.
The original image is read by (step S9). The image data of the document read at this time is recorded in the page memory. Next, the read original image is rotated 90 degrees by the image rotating means 51 (step S10). And
The LEF paper suitable for the previously inputted copy magnification is selected (S4), and the image forming processing by the image forming means 52 is executed (step S5). The image forming process in this case is
It is performed based on the image data read from the page memory, that is, the original image that has been rotated by 90 degrees.

As described above, in the present embodiment, when the original is set in the portrait orientation for a long processing time, the number of sheets (K) to be image-formed compensates for the time loss when the original image is rotated. Only when the number exceeds the standard number (J)
Since the image of the original is rotated 90 degrees to form the image using LEF paper, it is possible to always form the image in the shortest processing time regardless of the orientation of the original. Become.

Incidentally, the value of the reference number of sheets (J) to be compared with the number of sheets to be treated (K) is ideally determined by the above formula 1 in order to shorten the processing time as much as possible. However, while the number of copies is small, the difference in processing time due to the difference in the orientation of the original is small,
For example, some users may request that "the above-mentioned time saving function should be activated only when the number of copies exceeds 10." Therefore, as the value of the reference number of sheets (J), in addition to the value obtained by the above equation 1, various values can be set if it can be arbitrarily set in the environment setting mode of the copying machine or the like. It is possible to flexibly respond to the user's request.

[0034]

As described above, according to the image forming apparatus of the present invention, when the short side of the document is set parallel to the main scanning direction of the document reading unit, the number recognition unit recognizes it. The image rotation control means compares the number of processed sheets with a predetermined reference number of sheets, and when the number of processed sheets is larger than the reference number of sheets in the comparison result, the original image read by the image reading means is rotated by 90 degrees by the image rotating means, Since an image is formed by the image forming means based on the rotated original image, the LEF paper is automatically used even when the original is set in the portrait orientation, which requires a long processing time. The image forming process that has been performed can be executed. As a result, regardless of whether the document is set in portrait or landscape orientation, the image forming conditions with a short processing time are automatically selected. Even without doing so, it becomes possible to perform the copying work quickly and efficiently.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a basic configuration of a copying machine to which the present invention is applied.

FIG. 2 is a block diagram showing a basic configuration of an image processing system of a copying machine to which the present invention is applied.

FIG. 3 is a functional block diagram showing a main configuration of a copying machine to which the present invention is applied.

FIG. 4 is a block diagram showing an internal configuration of a page memory.

FIG. 5 is a principle diagram illustrating a specific example of image rotation processing.

FIG. 6 is a flowchart showing a processing procedure of a copying machine to which the present invention is applied.

[Explanation of symbols]

 50 image reading means 51 image rotating means 52 image forming means 54 number of sheets recognizing means 55 image rotation controlling means

Claims (3)

[Claims] 1. An image reading means for reading an original image by scanning an original set in a predetermined direction, and an image forming means for forming an image based on the original image read by the image reading means. In an image forming apparatus having the same, a sheet number recognition unit for recognizing the number of sheets to be image-formed, and a document image read by the image reading unit are
When the image rotation means capable of rotating once and the short side of the document are set in parallel to the main scanning direction of the image reading means, the number recognition means recognizes them before the image formation by the image formation means. An image rotation control means for comparing the processed number of sheets with a predetermined reference number and rotating the original image by 90 degrees by the image rotating means when the number of processed sheets is larger than the reference number. A characteristic image forming apparatus. 2. The image forming apparatus according to claim 1, wherein the image rotation control means sets, as the reference number, a compensation sheet number capable of compensating for a time loss when the document image is rotated. 3. The image forming apparatus according to claim 1, wherein the reference number of sheets can be set to an arbitrary value.