JP2004255646A - Image formation position adjusting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image formation position adjusting device which can correctly adjust a formation position of images. <P>SOLUTION: The device is configured to adjust the formation position of an object image to a recording material 81 at the time of forming the object image to the recording material 81 by an image formation apparatus. The image of the recording material 81 and a background body 88 are taken by a digital camera 27, and recording material image data D3a which represents an image of the recording material 81 is extracted from input image data D2a. In the device, a CPU 19 obtains a displacement amount with respect to a target position of the formation position of a test pattern to the recording material 81 on the basis of the recording material image data D3a, and the formation position of the object image in the image formation apparatus 30 is corrected on the basis of the displacement amount. The operator can correct the formation position of the image without requiring trouble. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for adjusting a formation position of a target image formed on a recording material by an image forming apparatus.
[0002]
[Prior art]
In a copying machine, a copying operation is first actually performed using the copying machine in order to adjust the formation position of an image on copy paper. Next, the operator measures the shift amount between the image formed on the copy sheet and the image on the original sheet by using a ruler, and calculates a correction value for correcting the shift amount. The correction value obtained in this way is input by operating the operation panel, and the central processing unit (CPU) in the copying machine adjusts the emission timing of the laser light and the like, and shifts the image formation position to the normal position. I am adjusting.
[0003]
In such a copying machine, an operator such as a serviceman measures a deviation amount of an image actually formed by the copying machine using a ruler, so that an error easily occurs, and differences due to individual differences of the operators are reduced. Will happen. In addition, since the adjustment is performed manually by the operator, the adjustment must be performed several times by repeating trial and error, and the operation time increases. In order to solve such a problem, there is a device that automatically adjusts the image forming position so to speak.
[0004]
FIG. 13 is a simplified front view showing the internal structure of a general-purpose terminal printer 1 according to the prior art. The general-purpose terminal printer 1 has a reading unit 3 and a printing unit 4 along the transport path 2. In the general-purpose terminal printer 1, while the installation sheet having the reference image inserted from the suction / discharge port 5 is transported in the first direction along the transport path 2, the image is read by the reading unit 3, and the image is printed by the printing unit 4. Prints superimposed on the installation paper. Next, while the installation sheet is transported along the transport path 2 in the second direction opposite to the first direction, the image is read by the reading unit 3, and the position of the reference image and the newly printed image is determined. The shift amount is detected. The printing position in the printing unit 4 is corrected based on the detection result (for example, see Patent Document 1).
[0005]
FIG. 14 is a block diagram schematically showing a configuration of another conventional printer 6. The printer 6 stores the correction value input by the input means 7 in the storage means 8, and corrects the printing position by the printing means 9 based on the correction value. An image representing a print medium printed by the printer 6 is obtained by the image reader 11, and a correction value is obtained from the shift amount of the printing position by the data processing means 10 based on the image. The data is input to the printer 6 and the printing position is corrected (for example, see Patent Document 2).
[0006]
[Patent Document 1]
JP-A-4-69267
[Patent Document 2]
JP-A-7-125314
[0007]
[Problems to be solved by the invention]
In the technique disclosed in Patent Document 1, the installation paper is repeatedly reciprocated between the reading device 3 and the printing unit 4, so that the skew caused by the influence of the transportation roller and the case where the installation paper is transported in the first direction. There is a problem that an accurate correction result is not always obtained due to the influence of a difference in the conveying speed when the sheet is conveyed in the second direction.
[0008]
The technique disclosed in Japanese Patent Application Laid-Open No. H11-157572 cannot accurately determine the amount of deviation when the print medium is not arranged at an accurate position due to, for example, skew of the print medium when the print medium is arranged on the image reader 11. There is a problem that an accurate correction result cannot be obtained.
[0009]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming position adjusting device capable of accurately correcting an image forming position.
[0010]
[Means for Solving the Problems]
The present invention is an apparatus for adjusting the formation position of a target image on a recording material when forming the target image on the recording material by the image forming apparatus,
Image input means for obtaining input image data representing an acquired image which is an image of a recording material on which a target image is formed by the image forming apparatus and a background body provided with the recording material;
Extracting means for extracting recording material image data representing a recording material image that is an image of the recording material from the input image data;
Calculation processing means for obtaining a shift amount of a formation position of the target image with respect to the recording material from the target position based on the recording material image data, and obtaining a correction value for correcting the formation position of the target image in the image forming apparatus. The image forming position adjusting device is characterized in that:
[0011]
According to the present invention, the input image data representing the image of the recording material and the background on which the target image has been formed by the image forming apparatus is input and provided to the extracting means. The extracting means extracts recording material image data representing an image of the recording material from the input image data, and provides the recording material image data to the arithmetic processing means. The arithmetic processing unit may determine a shift amount of a formation position of the target image with respect to the recording material with respect to the target position based on the recording material image data, and may obtain a correction value for correcting the formation position of the target image in the image forming apparatus. it can. The image forming position adjusting device can correct the forming position of the target image in the image forming device based on the correction value thus obtained.
[0012]
As described above, the image forming position adjusting device inputs the image of the recording material on which the target image is formed by the image forming device, together with the image of the surrounding background body, by the image input means, so that the target image for the recording material is automatically The formation position can be adjusted. Therefore, the operator does not need to measure the amount of deviation of the target image from the target position and calculate the correction amount for the recording material on which the target image is formed, thereby simplifying the operation and shortening the operation time. Can be. Further, not only the image of the recording material is obtained by the input means, but also the image of the surrounding background body is obtained together, and the recording material image data representing the recording material image is extracted from the input image data representing the obtained image. Therefore, when the image of the recording material is acquired, accurate recording material image data can be obtained even if the recording material is displaced from the input means called skew, for example. Therefore, based on the recording material image data, the amount of deviation of the formation position of the target image can be accurately obtained, a highly accurate correction value can be obtained, and the formation position of the target image can be corrected with high accuracy. The image data can be read into the image input means without worrying about the influence of the skew of the recording material, and it is not necessary to measure the shift amount, so that the operation time can be greatly reduced.
[0013]
Further, the invention is characterized in that the target image is a test pattern for adjusting the formation position of the target image.
[0014]
According to the present invention, the target image used when adjusting the formation position of the target image on the recording material is a test pattern for adjusting the formation position of the target image. The test pattern is an image in which the shift amount of the formation position can be easily obtained. By using this test pattern, the shift amount of the formation position of the target image with respect to the recording material can be obtained more accurately than in the case of using other than the test pattern. Thus, the position where the target image is formed on the recording material can be corrected with high accuracy.
[0015]
Further, the present invention is characterized in that the image input means is a digital camera which captures a recording material and a background to obtain digital image input image data.
[0016]
According to the present invention, by using a digital camera as the image input means, it is possible to easily obtain an acquired image including the recording material image by imaging the recording material together with the background. Also, input image data can be obtained as digital data. The digital data can be easily processed, the recording material image data can be extracted by the extracting means, and the digital data is hardly affected by noise, and the forming position can be corrected with high accuracy.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a block diagram of an image forming position adjusting device 12 according to an embodiment of the present invention. The image forming position adjusting device 12 is a device for adjusting the forming position of the target image on the recording material when the target image is formed on the recording material by the image forming device 30 such as a digital copying machine. The image forming position adjusting device (hereinafter sometimes simply referred to as “adjusting device”) 12 includes an image input unit 27, a cutout circuit 16 as an extracting unit, and a central processing unit (abbreviation: CPU) as an arithmetic processing unit. And 19). The image input unit 27 acquires and inputs input image data representing an acquired image which is an image of the recording material 81 on which the target image has been formed by the image forming apparatus 30 and the background 88 on which the recording material 81 is provided. The cutout circuit 16 extracts recording material image data representing a recording material image that is an image of the recording material 81 from the input image data. The CPU 19 obtains a shift amount of the target image formation position with respect to the recording material from the target position based on the recording material image data, and obtains a correction value for correcting the target image formation position in the image forming apparatus 30.
[0018]
The image forming apparatus 30 is an apparatus that forms an acquired target image on a recording material, and includes a light receiving unit 13, an A / D converter 14, a white / black correction circuit 15, a cutout circuit 16, a memory 17, An operation panel 18, a CPU 19, a laser control circuit 20, a laser diode 21, a laser light position detection unit (BD) 22, a drum 23, an exposure lamp (CL) 24, a decoding processing circuit 150, The distortion correction circuit 28 is included. The image forming position adjusting device 12 is a part of the image forming device 30 and includes a decoding processing circuit 150 as a decoding processing means, an image distortion correcting circuit 28 as an image distortion correcting means, It comprises a white / black correction circuit 15 as a black correction means, a cutout circuit 16 as a cutout means, a memory 17 as a storage means, a CPU 19 as a control operation processing means, and an image input means 27.
[0019]
Therefore, the image distortion correction circuit 28, the white / black correction circuit 15, the cutout circuit 16, the memory 17, and the CPU 19 are shared by the image forming position adjusting device 12 and the image forming device 30. The image input unit 27 is a unit externally connected to the image forming apparatus 30 in a detachable manner, and is realized by an imaging unit such as a digital camera.
[0020]
The image forming apparatus 30 irradiates the original 25 with illumination light from the exposure lamp 24 and receives reflected light at the light receiving unit 13 using a light receiving element (photoelectric conversion element) and a charge coupled device (Charge Coupled Device; CCD). Then, the target image formed on the document 25 is read. The reading unit 40 obtains a read image combining the document 25 and the platen behind the document 25. The read image has a document image area, which is an image of the document 25 on which the target image is formed, and a document table image area disposed therearound. The light receiving unit 13 photoelectrically converts the reflected light to generate read data VCCD of analog data representing a read image, and the read data VCCD is provided to the A / D converter 14 by an electric signal.
[0021]
The A / D converter 14 converts the read data VCCD, which is analog data, into read data D1 of digital data, and supplies the read data D1 of the digital data to the white / black correction circuit 15. The white / black correction circuit 15 corrects the variation of the output of the CCD in the light receiving unit 13 such as uneven light distribution and image variation to the read data D1 of the digital data to obtain a quantitative value. The white / black correction circuit 15 supplies the corrected read data D2 to the cutout circuit 16 by an electric signal.
[0022]
In the cutout circuit 16, image processing is performed on the corrected read data D2, and only the document image data D3 which is data of a document image area is extracted from the read data D2. The extracted document image data D3 is provided to the memory 17 and stored.
[0023]
In forming an image, the formed image data D3x stored in the memory 17 is given to the laser control circuit 20, and the emission data D4 based on the formed image data D3x is given to the laser diode 21, and the emission data D4 The laser beam is scanned from the laser diode 21 onto the photosensitive drum 23 and irradiated. As a result, the target image described on the document is formed as an electrostatic latent image on the surface of the photosensitive drum 23 based on the image data D3x. Further, the toner is adhered to the photosensitive drum 23 so as to correspond to the electrostatic latent image to be visualized to form a toner image, and the toner image is electrostatically transferred to a recording material and fixed. Thus, the target image is formed on the recording material 81.
[0024]
The formed image data D3x is data generated based on the document image data D3 given from the cutout circuit 16 in accordance with a command from the operation of the operation panel 18 by the operator. For example, in the case of a normal copy, which is the same magnification, and in which the correction such as the density is not performed, the formed image data D3x and the original image data D3 are the same. When enlargement, reduction, color correction, and the like are instructed, the formed image data D3x is data corrected from the document image data D3.
[0025]
The laser light position detector 22 is for knowing the reference position of the laser light. The reference position is a predetermined irradiation position of the laser beam. The CPU 19 receives the signal indicating the reference position from the laser light position detector 22, and acquires the reference position. The CPU 19 gives a command to the laser control circuit 20 based on the reference position of the laser light, adjusts the timing of giving the laser diode 21 the emission data D4 of the laser light corresponding to the image data D3, The timing of the emitted laser light is controlled.
[0026]
The CPU 19 is a unit that controls the image forming apparatus 30 as a whole. When the operation panel 18 is operated by the operator, a command such as a command for copying is input and given to the CPU 19. The CPU 19 controls each component included in the image forming apparatus 30 based on the input command so that the target image is formed on the recording material as described above.
[0027]
Further, the image distortion correction circuit 28 corrects the distortion of the image input by the image input means 27 and supplies the image to the white / black correction circuit 15. Such an image forming apparatus 30 is provided with an interface such as a universal serial bus (Universal Serial Bus: abbreviated as USB), and the image input unit 27 is configured to be detachably connectable via this interface. I have.
[0028]
The image input unit 27 is realized by a digital camera, and captures an image of the recording material 81 on which the target image has been formed by the image forming apparatus 30. At this time, the background material 88 is disposed behind the recording material 81, and a range including the background material 88 is imaged all around the recording material 81. As the background 88, a background having a color different from the color of the recording material 81 is preferably used. Thus, the recording material 81 and the background 88 are imaged, and the input image data D0a of the acquired image including the recording material 81 and the background 88 is input. The input image data D0a input by the image input unit 27 is digital data.
[0029]
If the image input unit 27 is a digital camera or the like, the input image data D0a may be encoded by a predetermined encoding method, such as being compressed by the JPEG method. That is, the image input unit 27 may be a unit that encodes and outputs data of an image obtained by imaging. In this case, since the image forming apparatus 30 on the receiving side needs a unit for decoding the input image data D0a, the decoding processing circuit 150 is provided. The input image data D0a is provided to the decoding processing circuit 150. The decoding processing circuit 150 decodes the input image data D0a, and supplies the decoded input image data D0ad to the image distortion correction circuit 28.
[0030]
Since the image input unit 27 is realized by a digital camera, the input image data D0a to be input is slightly distorted due to the aberration of the lens of the digital camera and the relative position between the lens and the recording material 81. There is a risk. The image distortion correction circuit 28 performs a process of correcting such image distortion to obtain original correct image data.
[0031]
The distortion-corrected input image data D1a is provided to the white / black correction circuit 15. The white / black correction circuit 15 corrects a variation in output of each pixel in the image input unit 27 such as uneven light distribution and image variation to obtain a quantitative value, similarly to the read data D1. The input image data D2a corrected in black and white in this manner is supplied to the cutout circuit 16.
[0032]
In the cutout circuit 16, as in the case of the read data D2, by performing predetermined image processing, only the image portion of the recording material 81 is extracted, and the recording material image data D3a representing the image of the recording material 81 can be obtained. . The extracted recording material image data D3a is provided to the memory 17 and stored.
[0033]
The memory 17 supplies the recording material image data D3a to the CPU 19. Conversely, the CPU 19 reads the recording material image data D3a from the memory 17 and analyzes it. In the present embodiment, the CPU 19 reads from the memory 17 line data D5a for one line extending in the main scanning direction among the recording material image data D3a. The main scanning direction is a direction corresponding to a direction in which the light receiving elements in the light receiving unit 13 of the image forming apparatus 30 are arranged in a line, and the sub-scanning direction is a direction in which the light receiving unit 13 moves. The CPU 19 analyzes the recording material image data D3a read from the memory 17, in this embodiment, the line data D5a, that is, analyzes the line data D5a, and detects a shift amount of the target image printed on the recording material 81 with respect to the recording material 81. Then, a correction value for correcting this deviation is obtained.
[0034]
Originally, the formation position of the target image on the document 25 and the formation position of the target image on the recording material 81 must match. However, the formation position actually formed on the recording material 81 may be different due to an attachment error of each component. In some cases, the target position corresponding to the formation position on the document 25 may be deviated. The amount of the shift is the shift amount, and the CPU 19 obtains the correction value for correcting the shift so as to be formed at the target position.
[0035]
FIG. 2 is a front view schematically showing the entire internal structure of the image forming apparatus 30. The image forming apparatus 30 includes a scanner unit 31, a laser printer unit 32, a multi-stage paper feed unit 33, and a sorter. The scanner unit 31 includes a document table 35 made of transparent glass 82, a two-sided automatic document feeder (RDF) 36, a scanner unit 40, a lamp reflector assembly 41, a light receiving unit 13, a reflection mirror 43, , A lens 44. The laser printer unit 32 includes a manual paper feed tray 45, a laser writing unit 46, an electrophotographic process unit 47, a fixing device 49, and a first transport path 50. The multi-stage paper feed unit 33 has a first cassette 51, a second cassette 52, a third cassette 53 and a fifth cassette 55, a common transport path 56, and second to sixth transport paths 57 to 61. .
[0036]
The laser writing unit 46 includes a laser diode 21 that emits a laser beam corresponding to image data from the memory 17, a polygon mirror 75 that deflects the laser beam at a constant angular velocity, and a laser beam that is deflected at a constant angular velocity. And an fθ lens 76 for correcting the light to be deflected at a constant speed on the photosensitive drum 23. The electrophotographic process unit 47 includes the photosensitive drum 23, a fixing device 49 and a charger (not shown) around the photosensitive drum 23, a developing device, a transfer device, a peeling device, a cleaning device, and a static eliminator. Have.
[0037]
The scanner unit 40 includes a lamp reflector assembly 41 for exposing the document 25, a plurality of reflection mirrors 43 for guiding a reflected light image from the document 25 to the light receiving unit 13, and a reflected light image from the document 25 formed on the light receiving unit 13. A lens 44 and an exposure lamp 24. The light receiving unit 13 is mounted on the lamp reflector assembly 41.
[0038]
The common transport path 56 is configured to transport the recording material from the first cassette 51, the second cassette 52, and the third cassette 53 toward the electrophotographic processing unit 47.
[0039]
The common transport path 56 joins the fourth transport path 59 from the fifth cassette 55 on the way to the electrophotographic process section 47 and communicates with the fifth transport path 60. The fifth transport path 60 joins the double-sided / combined transport path 50 b and the sixth transport path 61 from the manual paper feed tray 45 at a junction 62. The transport path that has joined at the junction 62 is configured to communicate with an image forming position between the photosensitive drum 23 of the electrostatographic processing unit 47 and the transfer device. A junction 62 between the fifth and sixth transport paths 60 and 61 and the double-sided / combined transport path 50b is provided at a position close to the image forming position.
[0040]
A first transport path 50 is provided downstream of the recording material on which an image is formed by the fixing device 49 in the transport direction. The first transport path 50 branches into a second transport path 57 leading to the sorter 34 and a third transport path 58 leading to the multi-stage paper feed unit 33.
[0041]
The third transport path 58 is branched in the multi-stage paper feed unit 33, and a reverse transport path 50a and a double-sided / combined transport path 50b are provided as the branched transport paths. The reversing conveyance path 50a is a conveyance path for reversing the front and back of the recording material in the duplex copying mode for copying both sides of the document 25. The double-sided / combined conveyance path 50b is a conveyance path for conveying a recording material such as copy paper from the reverse conveyance path 50a to the image forming position of the photosensitive drum 23 in the double-sided copy mode. The double-sided / synthetic conveyance path 50b is provided on the photosensitive drum without reversing the recording material in a single-sided synthetic copy mode in which an image of a different document or a different color toner is used to form an image on one side of the recording material. This is a transport path for transporting to the image forming position 23.
[0042]
The scanner unit 31 reads an image of the document 25 placed on the document table 35 while the scanner unit 40 moves along the lower surface of the document table 35. When using the automatic document feeder (RDF) 36 for two-sided printing, a plurality of documents 25 are set once, and the document 25 is automatically set in a state where the scanner unit 40 is stopped at a predetermined position below the RDF 36. While reading the document 25 one by one, or both sides, according to the operator's selection.
[0043]
Image data obtained by reading the image of the document 25 with the scanner unit 40 is temporarily stored in the memory 17. Thereafter, the image data is sent to an image processing unit based on a command from the operator via the operation panel 18 and subjected to various processes, and then temporarily stored in the memory 17 again. The data is given to the laser printer unit 32.
[0044]
The image data provided to the laser printer unit 32 is scanned by a laser beam by the laser writing unit 46 in the laser writing unit 46 and the electrophotographic processing unit 47, so that static electricity on the surface of the photosensitive drum 23 is charged. It is formed as an electrostatic latent image. The toner image visualized by the toner adhering to the electrostatic latent image is electrostatically transferred and fixed onto the surface of the recording material conveyed from the multi-stage paper supply unit 33. Thereafter, the recording material on which the image is formed is sent from the fixing device 49 to the sorter 34 via the first and second transport paths 50 and 57. Alternatively, the recording material on which the image has been formed is conveyed to the reverse conveyance path 50a via the first and third conveyance paths 50 and 58.
[0045]
FIG. 3 is a block diagram showing the image forming apparatuses 30 in groups related to control and image processing. The image forming apparatus 30 includes an image data input unit 70, an image processing unit 71, an image data output unit 72, the memory 17, and the CPU 19. The CPU 19 has an image processing control unit 74 that is responsible for controlling image processing.
[0046]
The image data input unit 70 has a CCD unit 70a, a histogram processing unit 70b, and an error diffusion processing unit 70c. The CCD unit 70a includes a light receiving unit 13, an A / D conversion circuit 14, and a white / black correction circuit 15. A histogram processing unit 70b and an error diffusion processing unit 70c are interposed between the white / black correction circuit 15 and the cutout circuit 16. The CCD unit 70a supplies the read data D2 to the histogram processing unit 70b as a digital signal of 256 gradations (8 bits).
[0047]
Instead of the white / black correction circuit 15, a circuit for performing MTF (Modulation Transfer Function) correction or gamma correction may be provided instead.
[0048]
The histogram processing unit 70b accumulates the number of pixels for each of the 256 grayscale pixel densities based on the read data D2 from the CCD unit 70a to obtain histogram data as density information. The histogram processing unit 70b supplies the obtained histogram data to the image processing 74 as necessary, and supplies the obtained histogram data to the error diffusion processing unit 70c together with the read data D2 as pixel data.
[0049]
In the error diffusion processing unit 70c, based on the histogram data, using an error diffusion method, which is a kind of pseudo halftone processing unit, in other words, a method of reflecting a binarization error in the binarization determination of an adjacent pixel. The read data D2 from the CCD unit 70a is converted into one bit (binary), and a redistribution operation is performed to faithfully reproduce the local area density in the document. In this way, the read data D2 is corrected and the corrected read data D2 is provided to the cutout circuit 16.
[0050]
The read data VCCD read by the light receiving unit 13 is binarized and white / black corrected by the A / D converter 14, and processed by the error diffusion method while taking a histogram based on the read data D2. The read data D2 after the processing is supplied to the cutout circuit 16. Then, the document image data D3 is cut out and temporarily stored in the memory 17.
[0051]
The input image data D1a provided from the image distortion correction circuit 28 to the white / black correction circuit 15 is also subjected to the same processing by the histogram processing unit 70b and the error diffusion processing unit 70c.
[0052]
The image processing unit 71 includes first and second multi-value processing units 71a and 71b, a combination processing unit 71c, a density conversion processing unit 71d, a scaling processing unit 71e, an image processing unit 71f, and an error diffusion processing. And a compression processing unit 71h. The image processing unit 71 is a processing unit that finally converts the document image data D3 into formed image data D3x desired by the operator based on the operation of the operation panel 18 by the operator. Processing is performed. The image processing unit 71 is configured to perform processing by the processing unit until the image data is finally stored in the memory 17 as converted image data. Each of the above-described processing units included in the image processing unit 71 functions as needed, and may not function in some cases.
[0053]
In the first and second multi-value processing sections 71a and 71b, the data binarized by the error diffusion processing section 70c is converted again into 256 gradations. The synthesis processing unit 71c selectively performs a logical operation for each pixel, that is, an operation of a logical sum, a logical product, or an exclusive logical sum. The data to be subjected to this calculation is image data stored in the memory 17. The density conversion processing section 71d arbitrarily sets the relationship between the input density and the output density for the 256-level digital signal based on a predetermined tone conversion table. The scaling unit 71e calculates the pixel data (density value) for the target pixel after scaling by performing an interpolation process based on the input known data in accordance with the designated scaling factor. After the multiplication, the main scanning is scaled.
[0054]
In the image processing unit 71f, various image processing is performed on the input pixel data, and information collection on a data string such as feature extraction is performed. The error diffusion processing unit 71g performs the same processing as the error diffusion processing unit 70c of the image data input unit 70. The compression processing unit 71h compresses the data into binary data by encoding called run length. As for the compression of image data, compression functions in the last processing loop when the final output image data is completed.
[0055]
The image data output unit 72 includes a restoration unit 72a, a multi-value processing unit 72b, an error diffusion processing unit 72c, and a laser output unit 72d. The laser output section 72d includes the laser control circuit 20 and the laser diode 21. The image data output unit 72 restores the formed image data D3x stored in the memory 17 in a compressed state by the restoration unit 72a, converts the original image data D3x back to the original 256 gradations by the multi-value processing unit 72b, and performs error diffusion. After the processing unit 72c performs error diffusion of the quaternary data that provides a smoother halftone representation than the binary data, the processed image data D3x after the processing is provided to the laser output unit 72d.
[0056]
Therefore, in the restoration unit 72a, the image data compressed by the compression processing unit 71h is restored. The multi-value processing section 72b performs the same processing as the multi-value processing sections 71a and 71b of the image processing section 71. The error diffusion processing section 72c performs the same processing as the error diffusion processing section 70c of the image data input section 70. In the laser output section 72d, the digital image data is converted into a laser on / off signal in the laser control circuit 20 based on the control signal from the CPU 19. The converted signal is given to the laser diode 21 and the laser light is turned on / off.
[0057]
The data handled by the image data input unit 70 and the image data output unit 72 is stored in the memory 17 in the form of binary data in order to reduce the capacity of the memory 17. Processing in the form of value data is also possible.
[0058]
FIG. 4 is a perspective view showing a configuration for operating the photosensitive drum 23 with laser light. The image forming apparatus 30 includes a laser writing unit 46, the photosensitive drum 23 of the electrophotographic process unit 47, and a reflection mirror 79, and these also configure the image forming value adjusting device 12. The laser writing unit 46 includes a polygon mirror 75, an fθ lens 76, and first and second laser beam position detectors 22a and 22b (hereinafter, when an unspecified laser beam position detector is indicated, a suffix “a”). , B ”is omitted and a reference numeral“ 22 ”is assigned).
[0059]
On both sides of the fθ lens 76, the first and second laser beam position detectors 22a and 22b are arranged at an interval from the fθ lens 76 so as to sandwich the fθ lens 76. The polygon mirror 75 is arranged on a vertical bisector of a straight line connecting the first laser light position detector 22a and the second laser light position detector 22b. The photosensitive drum 23 is arranged such that the rotation axis of the photosensitive drum 23 is perpendicular to the conveyance path of the recording material 81.
[0060]
The laser light position detector 22 is for detecting the reference position of the laser light by a BD signal which is an output signal obtained by irradiating the laser light position detector 22 with the irradiated laser light. The BD signal is a signal emitted from the position detector sensor 22 when the laser light is applied to the position detector sensor 22. Therefore, the CPU 19 can know the position of the laser beam by knowing which of the first and second position detector sensors 22a and 22b the BD signal is emitted from.
[0061]
The laser light emitted from the laser diode 21 is reflected by the polygon mirror 75 rotating around the axis and deflected at a constant angular velocity. The axis of the polygon mirror 75 is parallel to a plane perpendicular to the axis of the photosensitive drum 23. The laser light reflected by the polygon mirror 75 irradiates the laser light position detector 22 while moving at a constant angular velocity with respect to the rotation axis of the polygon mirror 75, and passes through the fθ lens 76. When the laser beam passes through the fθ lens 76, the laser beam is corrected so as to be deflected at a constant speed on the photosensitive drum 23, is reflected by the reflection mirror 79, and scans the photosensitive drum 23. The recording material 81 is conveyed in a direction 101 from the conveyance path to the photosensitive drum 23. The photosensitive drum 23 electrostatically transfers an image onto the surface of the recording material 81 while rotating in the direction 100 in which the recording material 81 is sent out.
[0062]
The image forming position adjusting device 12 corrects the position shift L1 of the main scanning line of the laser light emitted from the laser writing unit 46 to the photosensitive drum 23. Causes of the displacement L1 are a displacement of the relative position between the laser writing unit 46 and the photosensitive drum 23 and a displacement of the polygon mirror 75 and the fθ lens 76 inside the laser writing unit 46. The relative position L2 between the conveyed recording material 81 and the photosensitive drum 23 differs depending on the image forming apparatus 12, and therefore, it is necessary to adjust the relative position L2. Therefore, the image forming position adjusting device 12 absorbs a shift of each image forming device 12 by emitting a laser beam in accordance with the relative position between the recording material 81 and the photosensitive drum 23, and transfers the image to the recording material 81. It is formed at a regular position.
[0063]
FIG. 5 is a flowchart showing the adjustment A mode among the operations for adjusting the target image formation position, and FIG. 6 is a flowchart showing the adjustment B mode among the operations for adjusting the target image formation position. FIG. 7 is a plan view showing a state where the test chart 82 is placed on the transparent glass 83 of the document table 35 of the image forming apparatus 30. FIG. 8 is a diagram illustrating a procedure for acquiring the recording material image data D3a representing the recording material 81. FIG. 9 is a front view showing the recording material 81. FIG. 10 is a front view showing the test chart 82. FIG. 11 is a timing chart of emission of laser light.
[0064]
The operation of adjusting the test chart 82, which is the target image, to the formation position has an adjustment A mode and an adjustment B mode, and is executed from the adjustment A mode under the overall control of the CPU 19. In the adjustment A mode, the test chart 82 is printed on the recording material 81, and in the adjustment B mode, the amount of deviation is obtained to obtain a correction value.
[0065]
In the adjustment A mode, when started in step s0, in step s1, the CPU 19 determines whether or not a command to start the adjustment A mode is given by operating the operation panel 18. If a command to start the adjustment A mode has not been given, the process returns to step s1, and this step s1 is repeated until this command is given. If it is determined that a command to start the adjustment A mode has been given, the process proceeds to step s2.
[0066]
The operator operates the operation panel 18 to set the mode to the adjustment A mode, and places the test chart 82 on which the test pattern 90 is formed as the target image on the transparent glass 83 of the document table 35. As shown in FIG. 7, the test chart 82 has a print surface on which the test pattern 90 of the test chart 82 is formed facing the transparent glass 83, and the test chart 82 is printed on the position display plate 84 on which the document placement position mark 85 is formed. Along the one side edge 82a, the position in the direction in which the one side edge 82a extends is determined based on the mark 85, for example, by aligning the center position of the test chart 82 with the mark 85 so that the one side edge 82a extends. It is placed with alignment.
[0067]
In the present embodiment, an adjustment test chart 82 is used in the operation of adjusting the formation position of the target image. A test pattern 90 is formed on the test chart 82. The test pattern 90 is formed by, for example, a frame line 86 having a margin L3 uniformly from the four sides of an A4-size rectangle as shown in FIG. In the center of the test chart 82 in the longitudinal direction, there is provided a center line 87 extending over the entire region in the frame in the width direction. The test chart 82 is arranged such that one side edge 82 a arranged at one end in the width direction is along the position display plate 84.
[0068]
In step s2, the CPU 19 determines whether the print switch SW1 has been operated. If the print switch SW1 has not been operated, the process returns to step s2 and repeats step s2 until the print switch SW1 is operated. If it is determined that the print switch SW1 has been operated, the process proceeds to step s3.
[0069]
In step s3, the CPU 19 gives a command to the scanner unit 40 to read the test chart 82. Thus, the test chart 82 is read by the scanner unit 40. The light receiving unit 13 is realized by a line sensor having 5000 pixels and 400 dpi, and reads the light in a direction in which the light sensor 13 extends as a main scanning direction. For example, when using an A4 size test chart 82, the main scanning direction is arranged in the longitudinal direction of the test chart 82, and about 297 mm can be read in the main scanning direction to obtain line data.
[0070]
The light receiving unit 13 is mounted on the lamp reflector assembly 41 and is configured to be displaceable in a sub-scanning direction perpendicular to the main scanning direction, and obtains a plurality of line data in the sub-scanning direction by scanning the test chart 82. Thus, the data of the entire test chart 82, and thus the data of the test pattern 90, can be read. Among the data read in this manner, one-line data extending in the main scanning direction includes data of the center line 87 and the frame line 86 except for blank areas at both ends in the width direction. In this way, the original image data D3 representing the test chart 82 is stored in the memory, and the formed image data D3x is stored in the memory 17 based on this.
[0071]
In step s4, the CPU 19 gives a command to the laser control circuit 20 to irradiate the photosensitive drum 23 with laser light based on the formed image data D3x representing the test chart 82. Specifically, since the laser light is irradiated while scanning in the main scanning direction by the rotation of the polygon mirror, a state where the irradiation position in the main scanning direction matches the reference position is detected, and the laser beam is formed at a timing based on this. The laser beam is irradiated so as to form the image data D3x.
[0072]
More specifically, the CPU 19 counts the clock CLK given by the timer 8 from the falling edge of the BD signal based on the BD signal indicating the reference position from the BD 22, as shown in FIG. The memory 17 is controlled so that the formed image data D3x representing the read test chart 82 is supplied to the laser control circuit 20. The laser control circuit 20 supplies the emission data D4 corresponding to the given formed image data D3x to the laser diode 21, whereby the laser light is emitted from the first pixel to the photosensitive drum 23.
[0073]
In step s5, the CPU 19 controls so that the electrostatic latent image drawn on the photosensitive drum 23 is transferred and formed on the recording material 81 as a toner image, and the recording material 81 is discharged. Then, the process proceeds to step s6 to end the adjustment A mode. As described above, the adjustment A mode is a procedure in which the test pattern 90 is formed on the recording material 81 by the image forming apparatus 30 using the test chart 82.
[0074]
In the recording material 81 on which the test pattern 90 is formed as described above, it is assumed that the test pattern 90 is shifted in one longitudinal direction. Specifically, the center line 87 representing the center in the longitudinal direction is shifted from the center in the longitudinal direction of the recording material 81 to the R (rear) side, which is one side, as shown in FIG. I do. This means that the emission position of the laser light is shifted to the R side by a shift amount L4, so it is necessary to correct the laser light emission position to shift to the F (front) side by the shift amount L4. When such a shift occurs, it is necessary to correct the image forming position according to the shift amount. In order to determine the shift amount L4, it is necessary to determine the distance between the center line of the recording material 81 and the center line 87 of the test pattern 90 formed on the recording material 81.
[0075]
The procedure for obtaining and adjusting the shift amount is the adjustment B mode. As a preparation for executing the adjustment B mode, the recording material 81 on which the test pattern 90 of FIG. 8A is formed is imaged by the image reading means (hereinafter, sometimes referred to as a “digital camera”) 27. When an image is taken by the digital camera 27, in order to clearly detect the end of the recording material 81, the test material 90 is made to appear on the background 88 as shown in FIG. Is provided, and the recording material 81 and the surrounding background body 88 are imaged together. When capturing an image, the optical axis of the reading lens of the digital camera 27 is set to be perpendicular to the surface of the recording material 81 in order to minimize distortion of the captured image. When the recording material 81 itself is white, the color of the background body 88 is, for example, black or dark blue.
[0076]
In this manner, the digital camera 27 is image-formed by the image forming apparatus so that the recording material 81 can be imaged and the input image data D0a representing the acquired image captured by the digital camera 27 can be supplied from the digital camera 27 to the image distortion correction circuit 28. 30 and starts the adjustment B mode from step a0, and proceeds to step a1.
[0077]
In step a1, the CPU 19 determines whether or not a command to start the adjustment B mode has been given by operating the operation panel 18. If a command to start the adjustment B mode has not been given, the process returns to step a1 and repeats step a1 until this command is given. If it is determined that a command to start the adjustment B mode has been given, the process proceeds to step a2. The adjustment B mode is set by operating the operation panel 18 by the operator.
[0078]
In step a2, the CPU 19 determines whether or not the read switch SW2 has been operated. If the read switch SW2 has not been operated, the process returns to step a2, and repeats step a2 until it is operated. If it is determined that the read switch SW2 has been operated, the process proceeds to step a3. Thus, in step a2, the process waits for the operator to press the read switch SW2.
[0079]
In step a3, the CPU 19 controls the image distortion correction circuit 28 to read the input image data D0a representing the acquired image of the recording material 81 and the surrounding background 88 from the digital camera 27, and proceeds to step a4. move on. In step a4, the CPU 19 causes the image distortion correction circuit 28 to correct the input image data D0a, and proceeds to step a5.
[0080]
In step a5, the CPU 19 causes the white / black correction circuit 15 to correct the input image data D1a to correct the light distribution unevenness and the image variation to obtain a quantitative value, and then proceeds to step a6. At step a6, the CPU 19 causes the cutout circuit 16 to extract only the recording material image data D3a representing the recording material image as shown in FIG. 8C from the input image data D2a, and proceeds to step a7. In step a7, the CPU 19 causes the memory 17 to store the recording material image data D3a.
[0081]
In step a8, the CPU 19 reads line data D5a for one line in the main scanning direction from the recording material image data D3a from the memory 17. At this time, the line data D5a corresponding to the portion of the test chart 82 excluding the margin is read. Then, the process proceeds to step a9. In step a9, the CPU 19 analyzes the line data D5a and determines the amount of deviation L4 between the center line in the longitudinal direction of the recording material 81 and the center line 87 representing the center in the longitudinal direction of the test pattern 90 printed on the recording material 81. Ask. The shift amount L4 is a shift amount from the target position where the test pattern 90 should be formed. The shift amount L4 is obtained, and the process proceeds to step a10. In the present embodiment, the shift amount L4 is a value converted to a clock count, and is used as it is as a correction value.
[0082]
In step a10, it is determined whether the sign of the shift amount L4 is positive or negative. The sign of the deviation amount L4 indicates the direction of deviation of the test pattern 90 from the target position. For example, as shown in FIG. A shift of minus (-) indicates a shift in the other longitudinal direction, and a shift of plus or minus 0 (± 0) indicates no shift, that is, a shift amount L4.
[0083]
If the sign of the shift amount L4 is plus, the process proceeds to step a11. If it is minus, the process proceeds to step a12. If it is plus or minus 0, the process proceeds to step a13. When the sign is plus, the center line 87 representing the longitudinal center of the test pattern 90 printed on the recording material 81 is shifted to the R side which is one side with respect to the longitudinal center line of the recording material 81. I have. In this case, therefore, in step a11, the emission position of the laser beam is shifted to the F side, which is the other side, by a clock representing the emission timing so as to correct the shift amount L4 by the number of pixels corresponding to the shift amount L4. Is corrected by the correction value corresponding to the shift amount L4. That is, the clock count value n1 for providing the formed image data D3x to the control circuit is a value obtained by subtracting the shift amount L4 from the initial count value n.
[0084]
When the sign is minus, the center line 87 indicating the longitudinal center of the test pattern 90 printed on the recording material 81 is shifted to the F side with respect to the longitudinal center line of the recording material 81. In this case, therefore, in step a12, the emission position of the laser beam is shifted to the R side, which is one side, to correct the shift amount L4 by the number of pixels corresponding to the shift amount L4. Is corrected by the correction value corresponding to the shift amount L4. That is, the clock count value n1 for providing the formed image data D3x to the control circuit is a value obtained by adding the shift amount L4 from the initial count value n.
[0085]
After executing steps a11 and a12, the process proceeds to step a13. In step a13, the adjustment B mode ends.
[0086]
The correction of the formation position in the image forming apparatus 30 is performed by changing the timing at which the emission data D4 starts to be supplied from the laser control circuit 20 to the laser diode 21. In the present embodiment, the first pixel is printed from the F side of the recording material 81. Therefore, when it is desired to shift the formation position of the target image to the F side by L4, as shown in FIG. 11, in Step S31, the corrected count number n1 of CLK is obtained by n−L4 = n1, and emitted from the n1th CLK. What is necessary is just to set so that the data D4 is supplied from the laser control circuit 20 to the laser diode 21. When it is desired to shift the formation position of the target image to the R side by L4, the count number n1 of the corrected CLK is obtained by n + L4 = n1 as shown in step S32, and the emission data D4 is output from the laser control circuit 20 from the n1th CLK. What is necessary is just to set to give to the laser diode 21.
[0087]
FIG. 12 is a diagram showing a shift amount L4 of the scanning range of the laser beam on the photosensitive drum 23 before and after correction. In FIG. 12, a laser beam emitted from a laser diode (not shown) and having passed through the writing unit 46 scans a predetermined range of the photosensitive drum 23. The scanning range of the photosensitive drum 23 before the correction of the laser beam is the first scanning range R. As described with reference to FIG. 11, for example, when it is desired to shift the formation position of the target image 82 toward the F side by L4, the corrected CLK count number n1 is obtained by n−L4 = n1, and the emission data D4 is obtained from the n1th CLK. The laser control circuit 20 gives the laser diode 21. As a result, the scanning range of the photosensitive drum 23 after the correction of the laser beam can be set to the range of the second scanning range R1.
[0088]
Thereby, the formation position of the test chart 82 printed on the recording material 81 can be shifted to the F side by the shift amount L4, and the correct position of the recording material 81, in other words, the center position of the recording material 81 in the longitudinal direction. The center line 87 in the longitudinal direction of the test pattern 90 of the test chart 82 can be formed.
[0089]
The input image data D0a representing the images of the recording material 81 and the background 88 on which the target image has been formed by the image forming apparatus 30 described above is input and provided to the cutout circuit 16. The cutout circuit 16 extracts recording material image data D3a representing the image of the recording material 81 from the input image data D0a, and supplies the recording material image data D3a to the arithmetic processing unit. The arithmetic processing means calculates the amount of deviation of the formation position of the target image with respect to the recording material 81 from the target position based on the recording material image data D3a, and calculates a correction value for correcting the formation position of the target image in the image forming apparatus 30. You can ask. The image forming position adjusting device 12 can correct the forming position of the target image in the image forming device based on the correction value thus obtained.
[0090]
As described above, the image forming position adjusting device 12 automatically records the straight line of the recording material 81 on which the target image is formed by the image forming device 30 together with the image of the surrounding background body 88 by means of the image input means 27, that is, automatically. The position where the target image is formed on the material 81 can be adjusted. Therefore, the operator does not need to measure the amount of deviation of the target image from the target position and calculate the correction amount for the recording material 81 on which the target image has been formed, thereby simplifying the operation and shortening the operation time. Can be. Further, the input means obtains not only the image of the recording material 81 but also the image of the surrounding background 88, and converts the input image data D0a representing the acquired image into the recording material image data D3a representing the recording material image. Therefore, when the image of the recording material 81 is acquired, even if the recording material 81 is displaced from an input called skew, for example, accurate recording material image data D3a can be obtained. Therefore, based on the recording material image data D3a, the amount of deviation of the formation position of the target image can be accurately obtained, a highly accurate correction value can be obtained, and the formation position of the target image can be corrected with high precision. The operator can read the recording material 81 into the image input means without worrying about the influence of the skew, and it is not necessary to measure the displacement L4, so that the operation time can be greatly reduced.
[0091]
The target image used when adjusting the formation position of the target image on the recording material 81 is a test pattern 90 for adjusting the formation position of the target image. The test pattern 90 is an image in which the shift amount L4 of the formation position can be easily obtained, and by using the test pattern 90, the formation position of the target image on the recording material 81 is more accurate than in the case where a test pattern other than the test pattern 90 is used. The position of the target image on the recording material 81 can be corrected with high accuracy.
[0092]
In addition, by using a digital camera as the image input unit 27, an image including the recording material image can be easily obtained by imaging the recording material 81 together with the background 88. Further, the input image data D0a can be obtained as digital data. The digital data can be easily processed, the recording medium image data D3a can be extracted by the extracting means, and the digital data is hardly affected by noise, and the formation position can be corrected with high accuracy.
[0093]
In the present embodiment, the direction for automatically adjusting the formation position of the test chart on the recording material 81 with reference to the center line in the main scanning direction has been described. A similar method can be used to automatically adjust the test chart formation position on the recording material 81 based on the writing portion in the scanning direction.
[0094]
Although the image input unit 27 has been described as being configured to encode and output image data, it is not necessarily limited to this configuration, and may be configured to output without encoding. In this case, there is no need to decode the input image data D0a, and the decoding processing circuit 150 may not be provided. If the input image data is coded by providing a decoding processing circuit 150, the input image data is decoded by the decoding processing circuit 150, and then supplied to the image distortion correction circuit 28, and the input image data is coded. If not, the CPU 19 controls the decoding processing circuit 150 and the image distortion correction circuit 28 so that the decoding processing is not performed by the decoding processing circuit 150 but is supplied to the image distortion correction circuit 28. May be. In this case, the CPU 19 determines the encoding or non-encoding of the input image data according to the format of the image input means 27, etc., and if it is encoded, gives it to the encoding processing circuit 150, and it is not encoded In such a case, high-speed processing may be achieved by directly giving the signal to the image distortion correction circuit 28.
[0095]
【The invention's effect】
According to the present invention, the input image data representing the image of the recording material and the background on which the target image has been formed by the image forming apparatus is input and given to the extracting means. The extracting means extracts recording material image data representing an image of the recording material from the input image data, and provides the recording material image data to the arithmetic processing means. The arithmetic processing unit may determine a shift amount of a formation position of the target image with respect to the recording material with respect to the target position based on the recording material image data, and may obtain a correction value for correcting the formation position of the target image in the image forming apparatus. it can. The image forming position adjusting device can correct the forming position of the target image in the image forming device based on the correction value thus obtained.
[0096]
As described above, the image forming position adjusting device inputs the image of the recording material on which the target image is formed by the image forming device, together with the image of the surrounding background body, by the image input means, so that the target image for the recording material is automatically The formation position can be adjusted. Therefore, the operator does not need to measure the amount of deviation of the target image from the target position and calculate the correction amount for the recording material on which the target image is formed, thereby simplifying the operation and shortening the operation time. Can be. Further, not only the image of the recording material is obtained by the input means, but also the image of the surrounding background body is obtained together, and the recording material image data representing the recording material image is extracted from the input image data representing the obtained image. Therefore, when the image of the recording material is acquired, accurate recording material image data can be obtained even if the recording material is displaced from the input means called skew, for example. Therefore, based on the recording material image data, the amount of deviation of the formation position of the target image can be accurately obtained, a highly accurate correction value can be obtained, and the formation position of the target image can be corrected with high accuracy. The image data can be read into the image input means without worrying about the influence of the skew of the recording material, and it is not necessary to measure the shift amount, so that the operation time can be greatly reduced.
[0097]
According to the invention, the target image used when adjusting the formation position of the target image on the recording material is a test pattern for adjusting the formation position of the target image. The test pattern is an image in which the shift amount of the formation position can be easily obtained. By using this test pattern, the shift amount of the formation position of the target image with respect to the recording material can be obtained more accurately than in the case of using other than the test pattern. Thus, the position where the target image is formed on the recording material can be corrected with high accuracy.
[0098]
Further, according to the present invention, by using a digital camera as the image input means, it is possible to easily obtain an acquired image including the recording material image by imaging the recording material together with the background. Also, input image data can be obtained as digital data. The digital data can be easily processed, the recording material image data can be extracted by the extracting means, and the digital data is hardly affected by noise, and the forming position can be corrected with high accuracy.
[Brief description of the drawings]
FIG. 1 is a block diagram of an image forming position adjusting device 12 according to an embodiment of the present invention.
FIG. 2 is a front view schematically showing the entire internal structure of the image forming apparatus 30.
FIG. 3 is a block diagram showing the image forming apparatuses 30 in groups related to control and image processing.
FIG. 4 is a perspective view showing a configuration for operating a laser beam on a photosensitive drum 23.
FIG. 5 is a flowchart illustrating an adjustment A mode among operations for adjusting a formation position of a target image.
FIG. 6 is a flowchart illustrating an adjustment B mode among operations for adjusting a formation position of a target image.
FIG. 7 is a plan view showing a state where a test chart 82 is placed on a transparent glass 83 of a document placing table 35 of the image forming apparatus 30.
FIG. 8 is a diagram illustrating a procedure for acquiring recording material image data D3a representing the recording material 81.
FIG. 9 is a front view showing a recording material 81.
FIG. 10 is a front view showing a test chart 82.
FIG. 11 is a timing chart of emission of laser light.
FIG. 12 is a diagram illustrating a shift amount L4 of a scanning range of a laser beam on the photosensitive drum 23 before and after correction.
FIG. 13 is a simplified front view showing the internal structure of a conventional general-purpose terminal printer 1.
FIG. 14 is a block diagram schematically showing a configuration of another conventional printer 6.
[Explanation of symbols]
16 Cutout circuit
19 CPU
27 Image input means
30 Image forming apparatus
81 Recording Material
82 Test Chart
88 Background body
D0a Input image data
D3a Recording material image data

Claims (3)

An apparatus for adjusting a formation position of a target image on a recording material when the target image is formed on the recording material by the image forming apparatus,
Image input means for obtaining input image data representing an acquired image which is an image of a recording material on which a target image is formed by the image forming apparatus and a background body provided with the recording material;
Extracting means for extracting recording material image data representing a recording material image that is an image of the recording material from the input image data;
Calculation processing means for obtaining a shift amount of a formation position of the target image with respect to the recording material from the target position based on the recording material image data, and obtaining a correction value for correcting the formation position of the target image in the image forming apparatus. An image forming position adjusting device, comprising: The image forming position adjusting apparatus according to claim 1, wherein the target image is a test pattern for adjusting a forming position of the target image. 3. The image forming position adjusting device according to claim 1, wherein the image input unit is a digital camera that captures a recording material and a background to obtain input image data of digital data.

Images