JP2005266690A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which is capable of automatically executing an adjustment or notifying a requirement of the adjustment. <P>SOLUTION: An image forming apparatus comprises: an image reading means 2 for reading document image information; an image processing means 5 for applying predetermined image processing to read document image data; image output means 3, 4 for forming and outputting a toner image on a sheet based on the image data processed by the image processing means; a second image reading means 7 for reading a print image outputted by the image output means; an image comparison means 80 for comparing the print image data read by the second image reading means with the document image data; and a correction means 81 for correcting image data subjected to image processing by the image processing means based on a result of the comparison obtained by the image comparison means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus that employs an electrophotographic system, and in particular, an image reading unit that reads document image information, and an image processing unit that performs predetermined image processing on document image data read by the image reading unit. And an image forming apparatus including an image output unit that forms and outputs a toner image on a sheet based on the image data processed by the image processing unit.

  In an image forming apparatus for copying a manuscript image, various setting keys such as a manuscript type selection key such as a photo manuscript or a character manuscript and a reading density setting key are arranged on the operation unit. The original image data read by the image reading unit based on the setting of the image is subjected to the gradation processing and density value correction processing by the image processing unit, and printed on the paper by the image output unit based on the corrected image data. Is output.

  However, the gradation correction table data and the output process value are previously set in the gradation correction by the image processing unit and the output process by the image output means so that a standard output image assumed when copying a reference chart or the like is obtained. Even if a copy image that is actually output is processed according to the setting, the print image may be output with no significant difference from the original image due to changes over time of the apparatus or machine differences. It was not guaranteed.

  For this reason, it is difficult for the user to notice an abnormal printed image, and even if it is noticed, it is a time-consuming and difficult adjustment work for the image maintenance person to make detailed adjustments individually based on the request from the user. There was a problem of being complicated.

  SUMMARY OF THE INVENTION In view of the above-described conventional drawbacks, the present invention provides an image forming apparatus that can automatically perform adjustment work or notify the necessity of adjustment work.

  In order to achieve the above object, a first characteristic configuration of an image forming apparatus according to the present invention includes an image reading unit for reading document image information, and the image reading unit as described in claim 1 of the document of the claims. Image processing means for performing predetermined image processing on the original image data read by the means, and image output means for forming and outputting a toner image on a sheet based on the image data processed by the image processing means. A second image reading unit that reads a print image output by the image output unit, and compares the print image data read by the second image reading unit and the original image data. The image comparison means is provided.

  According to the above configuration, the print image output by the image output unit is read by the second image reading unit and compared with the original image data, so that the difference between the original image data and the print image data is automatically detected. It becomes possible to evaluate, and when the difference is large, it can be effectively used as basic data for performing appropriate processing.

  According to the second feature configuration, in addition to the first feature configuration described above, the image processing process data by the image processing unit is corrected based on a comparison result by the image comparison unit. It is in the point provided with the correction means to do.

  The image processing unit performs various processes on the input document image data and converts it into final output image data. For example, the image processing unit brings the document image data closer to the document image based on the reading characteristics of the image reading unit. Various corrections such as gradation correction processing based on the gradation correction table data set as described above, and density correction processing based on the density correction table data so that the density set by the read density setting key is achieved. The image correction process is performed. However, when it cannot be corrected properly due to changes over time, it becomes possible to make a clear determination as a result of comparison by the image comparison means. Therefore, in such a case, it is possible to obtain a print image close to the original setting by correcting the image processing process data such as the gradation correction table data and the density correction table data by the correction means. It is.

  According to the third feature configuration, the image output process by the image output unit is based on the comparison result by the image comparison unit in addition to the first or second feature configuration described above. A correction means for correcting data is provided.

  Similar to the above, the image output unit that prints the toner image on the paper based on the output image data processed by the image processing unit is also sensitive to a shift in the print start position and a change in sensitivity due to a change in the photoreceptor over time. If the abnormality of the print image data is found by comparison with the original image data, the correction means corrects the image output process data, for example, the output of the charging charger, the development bias value, and the print start timing. Thus, it becomes possible to obtain a print image close to the above setting.

  In the fourth feature configuration, in addition to any one of the first to third feature configurations described above, a notification that reports an abnormality based on a comparison result by the image comparison means. There is a means.

  In this case, even if it is a minor abnormality before the user notices the abnormality, an appropriate response can be quickly taken depending on the content notified by the notification means.

  As described above, according to the present invention, it is possible to provide an image forming apparatus that can automatically perform adjustment work or notify the necessity of adjustment work.

  Embodiments of an image forming apparatus according to the present invention will be described below. An image reading unit that reads document image information, an image processing unit that performs predetermined image processing on document image data read by the image reading unit, and a toner image on a sheet based on the image data processed by the image processing unit And a second image reading means for reading the print image output by the image output means, and the print image data and original image data read by the second image reading means A comparison by the image comparison means, a correction means for correcting the image processing process data by the image processing means, and an image output process data by the image output means based on a comparison result by the image comparison means, and a comparison by the image comparison means Based on a result, it is provided with the alerting | reporting means which alert | reports abnormality.

  This will be described in detail below. As shown in FIG. 1, a digital copying machine 1 as an image processing apparatus places an original to be copied (copy original) on the upper surface of a main body on which an image reading means 2 and image output means 3 and 4 are arranged. A contact glass 27 and an operation unit 6 are provided, and an automatic document feeder 28 is disposed on the contact glass 27 and a paper feed cassette 40 is disposed on one side of the main body.

  The image reading means 2 includes a first slider 2A having an exposure lamp 21 for exposing and scanning a document placed on the contact glass 27 and a first mirror 22 for reflecting reflected light from the document, and a first slider 2A. The second slider 2B having the second and third mirrors 23 and 24 for guiding the light reflected by the mirror 22 to the lens 25, and the optical information obtained by the condenser lens 25 for converting the light information into an electric signal. And a photoelectric conversion unit 26 including a solid-state image pickup device such as a CCD and an A / D converter for quantizing an output signal of the solid-state image pickup device.

  As shown in FIG. 2, the image processing means 5 receives the original image data from the photoelectric conversion unit 26, and performs shading correction and gradation so that the printed image by the image output means 3 and 4 can faithfully reproduce the original image. The image forming apparatus includes a CPU 50 that performs various image correction processes such as correction and density correction, and performs an enlargement / reduction process based on the document size and paper size, and a ROM 52, a RAM 53, and an image memory 51 that store processing programs. The RAM 53 stores correction tables such as gradation correction table data and density correction table data. The output image data after a series of image processing is performed on the document image data read by the image reading means 2 is output to the laser unit 38 of the image output means.

  Returning to FIG. 1, the image output means 3, 4 includes a photoconductive drum 31 that is rotated in the direction of the arrow by a main drive motor (not shown), and around the photoconductive drum 31 in the order of the rotation direction. A charger 32 that charges the photosensitive layer on the surface of the photosensitive drum 31, a developing device 33 that visualizes the electrostatic latent image formed on the photosensitive layer as a toner visible image, and a toner visible image formed on the photosensitive layer. The transfer discharger 34 for transferring the toner onto the sheet, the separation discharger 35 for separating the sheet from the photosensitive drum 31, the cleaning device 36 for removing the toner remaining on the photosensitive drum 31 after the transfer, and the photosensitive member A static eliminator 37 for removing the charge on the surface of the body drum 31 is provided, and the photosensitive layer uniformly charged by the charger 32 is irradiated with laser light corresponding to the image data output from the laser unit 38. Is, an electrostatic latent image is formed.

  Further, a paper feed roller 41 that feeds paper in the paper feed cassette 40, a registration roller 42 for transporting the paper sent by the paper feed roller 41 to the photosensitive drum 31 at a predetermined timing, and the photosensitive drum 31. The paper having the toner image formed thereon transferred and conveyed from the photosensitive drum 31 to the fixing roller 44 is provided with a conveying belt 43, and the paper subjected to the fixing process by the fixing roller 44 is discharged from the discharging roller 45. Is discharged onto the discharge tray 46.

  Between the fixing roller 44 and the discharge roller 45, there is provided a second image reading means 7 for reading a print image on a sheet on which a toner image is fixed. The second image reading means 7 is a CIS (comprising a CIS (integral lens array arranged at least in the width direction with the maximum sheet width) and a linear image sensor integrally arranged at the end image forming position of the lens array. Contact Image Sensor) is used.

  The system control unit 9 for system control of the digital copying machine 1 described above is necessary for a ROM that stores a predetermined operation program, a CPU that controls a required operation based on the program stored in the ROM, and processing by the CPU. As shown in FIG. 2, the image reading means 2, the image processing means 5, the image output means 3, 4 and the second are provided via a control bus 10, as shown in FIG. The image reading unit 7, the image correction processing unit 8, and the operation unit 6 are connected. Each block is configured such that a predetermined process is executed based on a command sent from the system control unit 9 via the control bus 10.

  The image correction processing unit 8 is configured to compare the print image data read by the second image reading unit 7 with the original image data, and the image processing unit based on the comparison result by the image comparison unit 80. 5 and the correction means 81 for correcting the image output process data by the image output means 3 and 4, and the notification means 82 for notifying abnormality based on the comparison result by the image comparison means 80. The

  The system control unit 9 drives and controls each element of the image reading unit 2, the image processing unit 5, and the image output units 3 and 4 at a predetermined timing, and prints image information sent to the laser unit 38 on a sheet. Configured to output. At this time, the print image fixed by the fixing roller 44 is read by the second image reading means 7 and stored in the image memory 51 of the image processing means 5, and the image comparison means 80 is stored in the image memory 51. The stored print image data and original image data are compared to determine whether density, gradation, image leading edge position, image formation width, image distortion, and the like are within the set range.

  When the density or gradation property deviates from the set range, the correction unit 81 corrects the gradation correction table data or the density correction table data as image processing process data stored in the RAM 53 of the image processing unit 5. The table data is corrected so as to fall within the original setting range, or the output value such as the output voltage of the charger 32 and the bias voltage of the developing device 33 as the image output process data of the image output means 3 and 4 is corrected. It is configured as follows.

  Further, when the leading edge position of the image is shifted, the correction unit 81 is configured to correct the driving timing data of the registration roller 42 as the image output process data of the image output units 3 and 4. The image output process data is provided in the image output means 3 and 4 with a CPU, ROM, RAM, etc. for performing sequence control on various elements, and the image output process data is stored in a battery-backed RAM or nonvolatile memory. Stored in

  The image comparison process data and the image output process data are feedback-controlled by the image comparison unit 80 and the correction unit 81, and a stable print image is always output.

  On the other hand, when the feedback control does not properly fall within the set range, the notification unit 82 is activated and configured to display an abnormal code so that the event can be recognized by the operation unit. It is configured so that the recognized user can promptly respond by contacting service personnel.

  Items to be compared and evaluated by the image comparison means 80 described above are not limited to those described above, and image processing process data and image output process data are merely examples.

Illustration of the image forming apparatus Control block diagram of image forming apparatus

Explanation of symbols

1: Image forming device (digital copier)
2: Image reading means 3, 4: Image output means 5: Image processing means 7: Second image reading means 80: Image comparison means 81: Correction means 82: Notification means

Claims (4)

An image reading unit that reads document image information, an image processing unit that performs predetermined image processing on document image data read by the image reading unit, and a sheet based on the image data processed by the image processing unit An image forming apparatus including an image output unit that forms and outputs a toner image,
A second image reading unit that reads the print image output by the image output unit; and an image comparison unit that compares the print image data read by the second image reading unit with the original image data. Image forming apparatus. The image forming apparatus according to claim 1, further comprising a correcting unit that corrects image processing process data by the image processing unit based on a comparison result by the image comparing unit. The image forming apparatus according to claim 1, further comprising: a correcting unit that corrects image output process data by the image output unit based on a comparison result by the image comparing unit. 4. The image forming apparatus according to claim 1, further comprising a notification unit configured to notify an abnormality based on a comparison result by the image comparison unit.

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