JP2005311480A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which outputs an image on the basis of image data, and allows a user to quickly and reliably do a re-output process when the image is abnormal. <P>SOLUTION: A data input means 26 takes image data in the image forming apparatus. A data transforming means 27 transforms the image data to write data, and sends the data to an exposure unit 7 which forms an electrostatic latent image on a photosensitive drum 5 on the basis of the sent write data. The data transforming means 27 also sends the transformed written data to a memory means 28. A control means 29 transforms a read output image by an output image reading means 22 to image data, and compares the image data with the write data stored in the memory means 28. An ejecting destination switching control means 30 instructs an ejecting destination switching means 23 to switch over the ejecting destination of a transfer paper 21 according to the comparison result sent from the control means 29. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus that outputs an image on paper based on image data captured from a personal computer, a scanner, or the like, and more particularly, to a process and an output mechanism when an abnormal image occurs.

  The configuration of a conventional image forming apparatus is shown in FIG. In FIG. 5, reference numeral 1 denotes an image forming apparatus. Here, a digital multi-function peripheral is shown as an example. In the image forming apparatus 1, when performing a copying operation, in the image forming unit 3 in the multifunction machine main body 2, the small-diameter photosensitive drum 5 that rotates in the direction A in the drawing is uniformly charged by the charging unit 4, An electrostatic latent image is formed on the photosensitive drum 5 by a laser beam from an exposure unit (laser scanning unit or the like) 7 based on the document image data read by the reading unit 6, and developed into an electrostatic latent image by the developing unit 8. An agent (hereinafter referred to as toner) is attached to form a toner image. The toner is supplied to the developing unit 8 from the toner container 9.

  The sheet is conveyed from the sheet feeding mechanism 10 to the image forming unit 3 via the sheet conveying path 11 and the registration roller pair 12 toward the photosensitive drum 5 on which the toner image is formed as described above. 3, the toner image on the surface of the photosensitive drum 5 is transferred to the sheet by the transfer roller 13 (image transfer unit). The sheet onto which the toner image has been transferred is separated from the photosensitive drum 5 and conveyed to a fixing unit 14 having a fixing roller pair 14a to fix the toner image. The sheet that has passed through the fixing unit 14 is sent to a sheet conveyance path 15 branched in a plurality of directions, and is routed by path switching mechanisms 21, 22, and 23 having a plurality of path switching guides provided at branch points of the sheet conveyance path 15. The transport direction is sorted, and the sheet is discharged to the sheet discharge section of the first discharge tray 17a, the second discharge tray 17b, or the third discharge tray 17c as it is (or after being sent to the sheet transfer path 16 and copied on both sides). .

  Although not shown, a static elimination device that removes residual charges on the surface of the photosensitive drum 5 is provided on the downstream side of the cleaning device 18. Further, the paper feed mechanism 10 is detachably attached to the multifunction machine main body 2 and includes a plurality of paper feed cassettes 10a and 10b for storing paper and a stack bypass (manual feed tray) 10c provided above the paper feed cassettes 10a and 10b. These are connected to the image forming unit 3 including the photosensitive drum 5 and the developing unit 8 by the paper transport path 11.

  Specifically, the sheet conveyance path 15 first branches into a left and right fork on the downstream side of the fixing roller pair 14a, and one path (a path branching rightward in FIG. 5) communicates with the first discharge tray 17a. It is configured as follows. The other path (the path that branches in the left direction in FIG. 5) branches into the upper and lower forks via the conveying roller pair 19, and the other path (the path that branches in the upper direction in FIG. 5) is the second discharge. It is configured to communicate with the tray 17b. On the other hand, the other path (the path branched in the downward direction in FIG. 5) is bifurcated immediately below the branch point, and one path passes through the discharge roller pair 20 to the third discharge tray 17c. The other path is configured to communicate with the paper transport path 16.

  In such an image forming apparatus, the reproducibility such as the position, density, and gradation of an output image may be reduced due to various factors. Therefore, a method for preventing the deterioration of the image quality has been proposed. Patent Document 1 detects the operation time of the photoconductor, the temperature around the photoconductor, the humidity, and the like, and the photoconductor based on the detection result. An image forming apparatus that corrects the amount of charge and the amount of exposure is disclosed. Patent Document 2 discloses a temperature of a fixing unit when a pattern image is formed in an image forming apparatus that forms a specific pattern image and determines an optimal image forming condition based on the density and chromaticity of the pattern image. A method of stably forming and reading a pattern image by changing the above is disclosed.

  However, even in the image forming apparatuses such as Patent Documents 1 and 2, after the user himself / herself actually looks at the output image and confirms whether there is an abnormality, it is determined whether or not to perform re-output. Therefore, especially when sending image data from a personal computer or the like to a printer located at a remote location via a network and outputting the image, the user may check the presence or absence of an abnormality only after getting the printed matter from his / her seat. If there was any abnormality in the image, it was necessary to return to his / her seat again to give an instruction for re-output and go back to get the printed material.

When image data is transmitted to a printer, the data is usually compressed and transmitted in order to increase the transmission speed. For this reason, it is necessary to convert the compressed data into image data again (ripping) on the printer side. However, once output is performed, the converted image data is deleted, so the image is output again. In this case, image data is retransmitted from a personal computer or the like, and it is necessary to newly rip the transmitted data on the printer side. Therefore, a print waiting time is required in addition to the user's travel time. Furthermore, even in a normal copying machine that does not transmit image data, if a large amount of copying is performed at one time, the user may leave the apparatus, and the process ends without noticing the abnormality of the image. There was a problem.
JP-A-8-30145 JP 2003-114552 A

  SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an image forming apparatus that outputs an image on a sheet based on image data, and that allows a user to quickly and reliably perform a re-output process when an abnormality occurs in the image. The purpose is to provide.

In order to achieve the above object, the present invention provides a data input means for inputting image data, a data conversion means for converting image data input by the data input means into write data, and a paper on the basis of the write data. An image forming unit that outputs an image to the image forming apparatus, a storage unit that stores the writing data, an output image reading unit that reads an image output on a sheet by the image forming unit, and the output A control unit that compares an image read by the image reading unit with the writing data stored in the storage unit to determine whether an output image is abnormal; a plurality of output trays from which paper after image output is discharged; And an output destination switching means for switching the output tray, and
The discharge destination switching means switches the output tray as a discharge destination when an abnormality is found in the output image by the control means.

  According to the present invention, in the image forming apparatus having the above-described configuration, the image forming unit is configured to display an image on a sheet based on the writing data stored in the storage unit when an abnormality is found in the output image by the control unit. Is output again.

  In the image forming apparatus having the above-described configuration, the data input unit is a data reading unit that reads image data via a network and / or an image reading unit that reads a document image and converts it into image data. It is said.

  According to the first configuration of the present invention, the image data output on the sheet is compared with the stored writing data to automatically determine whether there is an abnormality in the output image. Since the sheet is discharged to a place different from the normal position, the user can quickly notice the abnormal image, and the time required for the re-output process can be shortened. In addition, since the sheet on which the abnormal image is output does not coexist with the sheet on which the abnormal image is normally output, the abnormal image can be reliably eliminated.

  According to the second configuration of the present invention, in the image forming apparatus having the first configuration, when an abnormality is found in the output image, the image forming unit is configured to use the paper based on the write data stored in the storage unit. By re-outputting the image above, the user does not need to perform a re-output operation and does not need to perform ripping again on the image forming apparatus side. There is no risk of forgetting.

  According to the third configuration of the present invention, in the image forming apparatus having the first or second configuration, the data input unit reads the image data through the network or the information recording medium and / or the original image. When an abnormal image occurs when outputting an image created on a personal computer or a digital image on a network, or when outputting a document image by being an image reading means for converting into read image data Rapid re-output processing is possible.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the overall configuration of the image forming apparatus of the present invention. Portions common to FIG. 5 of the conventional example are denoted by the same reference numerals and description thereof is omitted. In FIG. 1, an image forming apparatus 1 is a digital copying machine of a type that outputs an image on transfer paper based on input image data. A data input unit 26, a data conversion unit 27, a storage unit 28, and a control unit 29. The discharge destination switching control means 30 is provided.

  The data input unit 26 captures a desired image converted into data into the image forming apparatus. The data input means 26 is a data reading means for taking a digital image stored on a web server on the Internet or an image created by a drawing application such as a personal computer into an image forming apparatus via a network, or a photograph or illustration. For example, an image reading unit such as a scanner for reading a document image as image data is used.

  The data conversion unit 27 converts the image data input by the data input unit 26 into write data and transmits it to the exposure unit 7. The exposure unit 7 forms an electrostatic latent image on the photosensitive drum 5 based on the transmitted writing data. Toner is attached to the electrostatic latent image by the developing unit 8 (see FIG. 5) to form a toner image, which is transferred from the paper feed mechanism 10 onto the transfer paper 21 conveyed through the paper conveyance path 11. . On the other hand, the image data converted into the write data by the data conversion means 27 is also transmitted to the storage means 28, and the storage means 28 stores the image data in the form of the write data.

  The control unit 29 converts the toner image read by the output image reading unit 22 into image data and compares it with the write data stored in the storage unit 28. The comparison result is transmitted to the discharge destination switching control means 30. The control unit 29 also controls the operation of each unit of the image forming apparatus based on a signal from an operation unit (not shown). The discharge destination switching control unit 30 instructs the discharge destination switching unit 23 (to be described later) to switch the discharge destination of the transfer paper 21 according to the comparison result of the image data transmitted from the control unit 29.

  As the output image reading means 22, for example, a line sensor or an area sensor constituted by a CCD element, a lens, a driver circuit, and the like are used. A line sensor is an imaging device that forms an image of an object on the surface of a CCD element by a lens, converts the amount of light into a video pulse signal, and outputs the video pulse signal. The width of the object to be measured is measured according to the position. Compared to an area sensor that captures an image of a certain area, the resolution is high and the image can be captured at high speed. When inspecting a continuously flowing object, the line sensor outputs a video for each scan. Therefore, continuous processing becomes easy. Therefore, it is particularly preferable to use a line sensor in the toner image abnormality inspection of the present invention.

  The index value to be compared with the image data can be set as appropriate depending on the type of abnormal image to be detected. For example, when an abnormality such as an image shift or distortion is targeted, the original image data (write data) stored in the storage unit 28 and the image data of the output image read by the output image reading unit 22 If the deviation of more than a predetermined dot is recognized, an abnormal image can be determined.

  On the other hand, when an image density or gradation abnormality is targeted, the areas of the black part (dot part) and the white part are calculated as index values and compared with the writing data stored in the storage means 28. When a variation of a predetermined amount or more is recognized, it can be determined as an abnormal image. At this time, for example, in the case of an image forming apparatus capable of printing a halftone image of 256 gradations, if the read image is converted into data for each gradation and compared with the written data, processing is performed particularly in a high-speed machine. Unable to follow speed. Therefore, among the images of a predetermined width read by the line sensor, for example, data for 1 to 200 gradations is set to 0, and data for 201 to 256 gradations is set to 1 to perform simplified data output. The comparison can be performed quickly.

  Here, the output image reading unit 22 is arranged between the image forming unit 3 and the fixing unit 14, but the arrangement position of the output image reading unit 22 is not limited to this, and for example, the fixing unit 14. It is also possible to arrange it immediately after. However, the sheet that has passed through the fixing unit 14 expands due to the influence of the heat of the fixing unit 14, so that the image is stretched. Further, the distance from the normal fixing unit 14 to the output trays 24 and 25 is short, and it is often difficult to provide the output image reading means 22 in terms of time and space.

  For this reason, when detecting an abnormality such as an image shift or distortion, it is preferable to dispose the toner image between the transfer and the fixing as in the present embodiment. On the other hand, since the density of the toner image is changed by being fixed on the sheet by the fixing unit 14, the output image reading means 22 is disposed downstream of the fixing unit 14 when detecting an abnormality in density or gradation. It is preferable to determine whether there is an abnormality in the final image after fixing.

  Based on an instruction from the discharge destination switching control unit 30, the discharge destination switching unit 23 sorts the discharge destination of the transfer paper on which the toner image is fixed by the fixing unit 14 into the output tray 24 and the abnormal image output tray 25. An example of the discharge destination switching means 23 is shown in FIG. The discharge destination switching means 23 has a substantially triangular cross section and is configured to be rotatable about a fulcrum 23a. An end 23b of the discharge destination switching means 23 is connected to the main body of the image forming apparatus via a tension spring 31, and a solenoid 32 is disposed in the vicinity of the end 23c opposite to the end 23b across the fulcrum 23a. Yes. The solenoid 32 is electrically connected to the discharge destination switching control means 30 and can reciprocate in the left-right direction in the figure in accordance with a control signal from the discharge destination switching control means 30.

  When the transfer paper discharge destination is the output tray 24, the solenoid 32 does not act on the discharge destination switching means 23 as shown in FIG. 2A, and the discharge destination switching means 23 is driven by the urging force of the tension spring 31. The paper conveyance path 15a that leads to is communicated, and the paper conveyance path 15b that leads to the abnormal image output tray 25 (see FIG. 1) is closed. As a result, the transfer paper that has passed through the fixing unit 14 passes through the paper transport path 15 a and the discharge roller 20 along the arrow A, and is discharged to the output tray 24.

  On the other hand, when the discharge destination of the transfer paper is the abnormal image output tray 25, the solenoid 32 presses the end 23c in the right direction in the figure by a signal from the discharge destination switching control means 30, as shown in FIG. . The discharge destination switching means 23 rotates counterclockwise around the fulcrum 23 a against the urging force of the tension spring 31, closes the paper conveyance path 15 a leading to the output tray 24, and conveys paper to the output tray 25. The path 15b is connected. As a result, the transfer paper that has passed through the fixing unit 14 passes along the paper conveyance path 15 b along the arrow B and is discharged to the abnormal image output tray 25.

  Note that the shape and arrangement of the tension spring 31 and the solenoid 32 are appropriately set according to the specifications of the image forming apparatus, and a compression spring, a torsion spring, or the like can be used instead of the tension spring 31. Further, here, switching of two discharge destinations by the discharge destination switching means 23 has been described, but switching of three or more locations can be described in exactly the same manner. For example, in the case of a double-sided printing type image forming apparatus provided with a duplex unit, it is possible to switch to a sheet conveyance path leading to the duplex unit in addition to two ejection destinations by the ejection destination switching means 23.

  Next, the operation of the image forming apparatus of this embodiment will be described. FIG. 3 is a flowchart showing an image forming procedure by the image forming apparatus of the present invention. The image forming operation of the image forming apparatus will be described with reference to FIG. In this operation procedure, first, a desired image is captured from a network, a personal computer, or a document by the data input means 26 (step S1). Next, the read image data is converted into writing data by the data conversion means 27 (step S2), stored in the storage means 28 (step S3), and transmitted to the exposure unit 7 of the image forming unit, so that the photoconductor. An electrostatic latent image is formed on the drum 5. Further, a toner image corresponding to the formed latent image is formed, and the toner image is transferred onto the transfer paper 21 conveyed by the paper conveying means 11 (step S4).

  Next, the toner image on the transfer paper 21 is read by the output image reading means 22 (step S5) and transmitted to the control means 29. The control means 29 uses the transmitted image as predetermined image data, and determines whether or not there is an abnormality in the image output on the transfer paper 21 in comparison with the write data stored in the storage means 28 in step S2. Judgment is made (step S6). The determination result is transmitted to the discharge destination switching control means 30, and when it is determined that there is no abnormality, the discharge destination switching control means 30 designates the normal output tray 24 as the discharge destination. Thereafter, the toner image is fixed on the transfer paper 21 by the fixing unit 14 (step S7), the transfer paper 21 is discharged to the output tray 24, and the process is ended (step S8).

  On the other hand, if it is determined in step S 6 that there is an abnormality in the image, the discharge destination switching unit 23 switches the discharge destination to the abnormal image output tray 25 in accordance with an instruction from the discharge destination switching control unit 30. Thereafter, after the toner image is fixed on the transfer paper by the fixing unit 14 (step S9), the transfer paper is discharged to the abnormal image output tray 25 (step S10). Further, returning to step S4, the image output operation is repeated in the same manner (steps S4 and S5). If a normal image is output, the process is terminated (steps S6 and S7). If an abnormality is found again, the switching of the discharge destination and the re-output operation are repeated in the same manner as described above.

  The operation of step S6 for determining whether or not the toner image is abnormal will be described in more detail with reference to FIG. When the toner image on the transfer paper is read by the output image reading means 22 in step S5 (see FIG. 3), the control device 29 first determines whether or not the toner image is displaced (step S61). Here, 100 dots is set as the threshold for determining image misalignment, and when it is determined that the image misalignment is 100 dots or more, the discharge destination switching control means 30 sends the discharge destination switching means 23 to the discharge destination switching means 23. Switching is instructed (step S62), and the discharge destination switching means 23 switches the discharge destination to the abnormal image output tray 25 (step S63).

  If it is determined in step S61 that the image shift is smaller than 100 dots, it is then determined whether there is a density shift (step S64). Here, 10% is set as the threshold for determining the density deviation, and when it is determined that the variation in the area ratio between the dot portion and the white portion is 10% or more compared to the original data, the discharge destination The switching control unit 30 instructs the discharge destination switching unit 23 to switch the discharge destination (step S62), and the discharge destination switching unit 23 switches the discharge destination to the abnormal image output tray 25 (step S63).

  On the other hand, if it is determined in step S64 that the density deviation is smaller than 10%, the discharge destination switching control means 30 designates the normal output tray 24 as the discharge destination, and the discharge destination switching means 23 switches the discharge destination. The process ends without performing it. Here, the image abnormality is determined with respect to the image shift and the density shift, but only one of them may be determined. Further, the order of determination is not limited to this, and it is also possible to determine in order of density shift and image shift.

  In the above embodiment, only the digital copying machine has been described as the image forming apparatus. However, the present invention can be applied to other types of copying machines such as a tandem color copying machine and an analog monochrome copying machine, or a facsimile or laser printer. Of course, the present invention can also be applied to an image forming apparatus such as the above. For example, when applied to a color copying machine, it is also possible to determine an image abnormality with respect to color misregistration and color unevenness of toner images of each color.

  The present invention relates to data input means for inputting image data, data conversion means for converting image data input by the data input means into write data, and image forming means for outputting an image on a sheet based on the write data. An image forming apparatus comprising: storage means for storing write data; output image reading means for reading an image output on a sheet by the image forming means; and storing an image read by the output image reading means. Control means for comparing the writing data stored in the means to determine whether or not there is an abnormality in the output image, a plurality of output trays for discharging the paper after image output, and a discharge destination switching means for switching the output tray The discharge destination switching means switches the output tray as the discharge destination when an abnormality is found in the output image by the control means. It is assumed that.

  As a result, in the image forming apparatus that outputs an image on a transfer sheet based on the input image data, the stored image data and the image data of the output image are compared to automatically determine whether there is an abnormality in the output image. However, if an abnormality is found, the paper is ejected to a different location than usual, so the user can quickly notice the abnormal image, shorten the time required for re-output, and reliably eliminate the abnormal image. An excellent image forming apparatus is provided.

  Further, when an abnormality is found in the output image, the image forming unit re-outputs the image on the paper based on the writing data stored in the storage unit, so that the user does not need to perform a re-output operation. Further, since ripping is not required at the time of re-output, a quick re-output process is possible and there is no possibility of forgetting to re-output.

  Further, when the data input means is a data reading means for inputting image data via a network or an image reading means for reading an original image, an image created on a personal computer or a digital image on a network is output, or In any case of outputting a document image, it is possible to provide an image forming apparatus capable of quick re-output processing when an abnormal image occurs.

FIG. 1 is a schematic diagram showing an overall configuration of an image forming apparatus of the present invention. FIG. 4 is an enlarged cross-sectional view around a discharge destination switching unit of the image forming apparatus of the present invention. These are the flowcharts which show the image formation procedure by the image forming apparatus of this invention. FIG. 5 is a flowchart illustrating a procedure for determining whether or not a toner image is abnormal. FIG. 1 is a schematic diagram illustrating an overall configuration of a conventional image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Main body 3 Image forming part 4 Charging unit 5 Photoconductor drum 6 Image reading part 7 Exposure unit 8 Developing unit 9 Toner container 11 Paper conveyance path 14 Fixing part 15a, 15b Paper conveyance path 21 Transfer paper 22 Output image reading Means 23 Output destination switching means 24 Output tray 25 Abnormal image output tray 26 Data input means 27 Data conversion means 28 Storage means 29 Control means 30 Output destination switching control means

Claims (3)

Data input means for inputting image data, data conversion means for converting image data input by the data input means into writing data, and image forming means for outputting an image on a sheet based on the writing data In the provided image forming apparatus,
Storage means for storing the write data, output image reading means for reading an image output on the paper by the image forming means, and the writing stored in the storage means for an image read by the output image reading means Control means for comparing the data with each other to determine whether there is an abnormality in the output image, a plurality of output trays for discharging the paper after image output, and a discharge destination switching means for switching the output tray are provided. And
The image forming apparatus, wherein the discharge destination switching unit switches the output tray as a discharge destination when an abnormality is found in the output image by the control unit.   The image forming unit re-outputs an image on a sheet based on the writing data stored in the storage unit when an abnormality is found in the output image by the control unit. The image forming apparatus described.   3. The image according to claim 1, wherein the data input means is a data reading means for reading image data via a network and / or an image reading means for converting a document image into read image data. Forming equipment.

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