JP2013046231A - Image forming apparatus, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus in which a degree and a cause of variation in results of reading executed in one unit of image forming process are highly accurately grasped, and a program for it.SOLUTION: When the side reference of a window glass 286 is read by a CCD sensor 204 for every inspection image formed in a storage medium P in image forming instructions and the distribution characteristic of the result obtained by reading indicates a predetermined distribution characteristic as an abnormal distribution characteristic, lamp abnormality warning information is output, and when a margin area is read by the CCD sensor 204 for every inspection image formed in the storage medium P in the image forming instruction, and the distribution characteristics of the result obtained by reading indicates a predetermined distribution characteristic as an abnormal distribution characteristic, margin area abnormality warning information is output.

Description

  The present invention relates to an image forming apparatus and a program.

  Japanese Patent Application Laid-Open No. 2004-133830 discloses a memory that stores data for correcting the periodic distribution unevenness of the light source light amount in a reading apparatus including a non-uniformity correction circuit that corrects a non-uniformity fluctuation component appearing in a read signal of an image sensor. Are connected between the image sensor and the non-uniformity correction circuit so that the memory can be synchronized with the read signal of the image sensor when connected between the image sensor and the non-uniformity correction circuit. There is disclosed a transmitted light type reading apparatus comprising a periodic unevenness correction circuit that reads out correction data from the light source and thereby removes the periodic unevenness of the light source light amount.

  In Patent Document 2, in an image reading apparatus having an illuminating unit that illuminates a document and a solid-state imaging device that reads a document image illuminated by the illuminating unit in units of one line, a white reference plate is read by the solid-state imaging device. There is disclosed an image reading apparatus comprising control means for controlling a driving time for driving a solid-state imaging device in accordance with an output level at that time.

  In Patent Document 3, a print pattern continuously printed on a printing paper is input by an image input device, and the result of a printed matter is inspected by comparing the image data with image data of a normal print pattern input in advance. In the printed matter inspection apparatus, a normal blank page portion is inputted in advance by the image input device, the blank portion is detected between the first memory for storing this image data and the print pattern of the print paper, and the image is input by the image input device. A blank sheet detection unit that performs input, a correction coefficient calculation unit that calculates a correction coefficient based on a ratio of image data in a blank sheet portion between patterns and image data in the first memory, and the calculated correction coefficient are stored. A printed matter inspection comprising: a second memory; and a correction unit that corrects image data of a print pattern input by an image input device using a correction coefficient in the second memory. Location is disclosed.

  In Patent Document 4, an image sensor configured by arranging a plurality of photoelectric conversion elements that convert document information into an electrical signal for each pixel, an amplifier that amplifies the output from the image sensor, and the output from the amplifier is digital. An A / D converter that converts data, a white level memory that stores reference white level information for each pixel when the reference white level light quantity of the image sensor is given, and original reading An edge white reflector reflection light level detection circuit for detecting the reflected light level of the white reflector provided at the window edge from the output of the A / D converter, a white level memory and each pixel signal from the A / D converter A non-uniformity correction circuit that corrects to a linear value based on the value of the black level memory, and the light intensity distribution from the reference white level information for each pixel of the white level memory, The amplifier light quantity distribution maximum value detecting means for detecting the maximum value of the quantity distribution and the edge white reflector reflection light level detected by the edge white reflector reflection light level detection circuit are set to a predetermined target value. While adjusting the gain, the target value is used based on the maximum light intensity distribution value detected by the light intensity distribution maximum value detecting means and the predetermined A / D maximum input level that can be processed by the A / D converter. There is disclosed an electronic image reading apparatus characterized by having an amplifier gain adjusting means for changing an amplifier gain.

  In Patent Document 5, shading is performed without using a white reference surface when converting received light obtained by irradiating light source light onto a document with an optical sensor into an electrical signal according to the received light quantity. An image reading processing apparatus having at least a shading correction function for performing correction, the image reading processing apparatus including an arithmetic unit that detects a background of a read document and calculates a white reference value from the detected background A processing device is disclosed.

JP-A-63-256056 Japanese Patent Laid-Open No. 04-188942 Japanese Patent Laid-Open No. 04-232056 JP 05-276379 A JP-A-11-168626

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus and a program capable of accurately grasping the degree and cause of variations in the results of reading performed within one unit of image forming processing.

  In order to achieve the above object, the image forming apparatus according to claim 1, wherein a plurality of inspections are performed in one unit of image forming processing using an image including a blank area inside or having a blank area around as an inspection image. An image forming unit that forms an image for inspection or an image other than the image for inspection on a recording medium; and when the plurality of inspection images are formed, each of the inspection image and the blank area is read and the inspection A reading unit that reads a reference plate for adjusting image quality each time an image for reading is read, and the reading unit reads the reference plate for each inspection image formed by the image forming unit within one unit of the image forming process. When the distribution characteristic of the result obtained in this way is abnormal, it is detected that the reading result of the reference plate is abnormal, and is formed by the image forming means within one unit of the image forming process. Detecting means for detecting that the reading result of the blank area is abnormal when the distribution characteristic of the result obtained by reading the blank area by the reading means for each of the inspection images is abnormal. Consists of.

  According to a first aspect of the present invention, in the image forming apparatus according to the second aspect of the invention, the reading unit further reads the reference plate for each unit of the image forming process, and the detecting unit Further, it detects that the reading result of the reference plate is abnormal when the distribution characteristic of the result obtained by reading the reference plate by the reading unit for each unit of the image forming process is abnormal. It is also good.

  According to a second aspect of the present invention, the distribution characteristics of the result obtained by reading the reference plate by the reading unit for each unit of the image forming process as in the third aspect of the invention. The evaluation value for evaluating the image may be an error of a result obtained by reading the reference plate by the reading unit for one unit of the image forming process before and after.

  In addition, the image forming apparatus according to any one of claims 1 to 3, and the reference plate may be the image for inspection or an image other than the image for inspection as in the invention according to claim 4. May be arranged at a position that does not overlap with a predetermined region as a region to be read by the reading unit and is read by the reading unit when the inspection image is read by the reading unit.

  Further, in the image forming apparatus according to any one of claims 1 to 4, as in the invention according to claim 5, the reading unit includes the inspection image or an image other than the inspection image. An illumination unit that illuminates a predetermined reading region as a region to be read, and a reading unit that reads the inspection image arranged in the reading region illuminated by the illumination unit. The reading of the blank area and the reference plate by the reading unit in a unit may be a reading within one illumination period by the illumination unit.

  Further, the image forming apparatus according to any one of claims 1 to 5 is formed by the image forming unit within one unit of the image forming process as in the invention according to claim 6. The image forming means within one unit of the image forming process uses an evaluation value for evaluating the distribution characteristics of the result obtained by reading the reference plate by the reading means together with the margin area corresponding to each inspection image. It is also possible to use an error of the result obtained by reading the reference plate by the reading means for the inspection image whose formation time depends on the time.

  Further, the image forming apparatus according to any one of claims 1 to 6 is formed by the image forming unit within one unit of the image forming process as in the invention according to claim 7. An evaluation value for evaluating a distribution characteristic of a result obtained by reading the blank area corresponding to the inspection image by the reading unit is determined by the formation time by the image forming unit within one unit of the image forming process. An error may be obtained as a result obtained by reading the blank area by the reading unit with respect to the preceding and following inspection images.

  An image forming apparatus according to any one of claims 1 to 7, wherein an image is formed by the image forming unit based on a reading result by the reading unit as in the invention according to claim 8. You may comprise further the adjustment means which adjusts the conditions used when forming.

  According to an eighth aspect of the present invention, in the image forming apparatus according to the ninth aspect, after the abnormality is detected by the detection unit, the latest reading result by the reading unit can be adjusted by the adjustment unit. A first adjustment instruction that is an instruction to be used, a second adjustment instruction that is an instruction to use a reading result that is not up-to-date by the reading means for adjustment by the adjusting means, and a re-execution instruction that is an instruction to re-execute reading by the reading means. A receiving unit that accepts the condition, and the adjusting unit adjusts the condition based on a latest reading result by the reading unit when the first adjusting instruction is received by the receiving unit; When the second adjustment instruction is accepted, the condition is adjusted based on the latest reading result by the reading unit, and the reading unit includes: When the re-execution instruction is accepted by the serial receiving means may be one that re-execute the reading by said reading means.

  In order to achieve the above object, the program according to claim 10, wherein a plurality of inspection images are formed in one unit of image forming processing using an image including a blank area inside or having a blank area around as an inspection image. Alternatively, an image forming unit that forms an image other than the inspection image on a recording medium, and when the plurality of inspection images are formed, each of the inspection image and the blank area is read and the inspection image A computer that controls an image forming apparatus including a reading unit that reads a reference plate for image quality adjustment every time the image is read, for each of the inspection images formed by the image forming unit within one unit of the image forming process. Means for detecting that the reading result of the reference plate is abnormal when the distribution characteristic of the result obtained by reading the reference plate by the reading means is abnormal; and The reading result of the blank area when the distribution characteristic of the result obtained by reading the blank area by the reading unit for each of the inspection images formed by the image forming unit within one unit of the forming process is abnormal It is intended to function as a means for detecting that is abnormal.

  According to the first and tenth aspects of the present invention, the distribution characteristic of the result obtained by reading the reference plate by the reading unit for each inspection image formed by the image forming unit within one unit of the image forming process is obtained. A warning indicating that the reading result of the reference plate is abnormal in the case of abnormality is output, and the blank area is generated by the reading unit for each inspection image formed by the image forming unit within one unit of the image forming process. Compared with the case where the configuration of detecting that the reading result of the blank area is abnormal when the distribution characteristic of the result obtained by reading the image is abnormal is read in one unit of image forming processing As a result, it is possible to obtain the effect that the degree and cause of the variation in the results can be grasped with high accuracy.

  According to the invention of claim 2, the reading unit further reads the reference plate for each unit of the image forming process, and the output unit further reads the reference plate by the reading unit for each unit of the image forming process. Compared to the case where there is no configuration for detecting that the reading result of the reference plate is abnormal when the distribution characteristic of the result obtained is abnormal, the result of the reading performed for each unit of the image forming process There is an effect that the degree and cause of the variation can be grasped with high accuracy.

  According to the invention of claim 3, the evaluation value for evaluating the distribution characteristic of the result obtained by reading the reference plate by the reading unit for each unit of the image forming process is read for each unit of the preceding and following image forming processes. Compared with the case where there is no error as a result of reading the reference plate by means, the degree and cause of the variation in the result of reading performed for each unit of image formation processing can be grasped easily and with high accuracy. The effect that it is done is acquired.

  According to the invention according to claim 4, the reference plate is a position where the inspection image or an image other than the inspection image does not overlap with a predetermined region as a region where the reading unit reads the image. As compared with the case where the reading unit does not have a configuration where the reading unit reads the reading unit, the effect of contributing to efficient reading can be obtained.

  According to the fifth aspect of the present invention, the reading unit illuminates a reading area that is predetermined as an area from which an image for inspection or an image other than the image for inspection is read, and reading illuminated by the lighting section. A reading unit that reads an image for inspection arranged in the region, and reading of the blank area and the reference plate by the reading unit in one unit of image forming processing is set as reading within one illumination period by the lighting unit. As compared with the case where the configuration is not provided, there is an effect that the degree of illumination variation within one unit of the image forming process can be grasped with high accuracy.

  According to the sixth aspect of the present invention, the distribution characteristics of the result obtained by reading the reference plate by the reading unit together with the blank area corresponding to each inspection image formed by the image forming unit within one unit of the image forming process. When the evaluation value for evaluating the image is not an error of the result obtained by reading the reference plate by the reading means for the inspection image whose formation time by the image forming means is within one unit of the image forming process As compared with the above, there is an effect that the degree of variation in the result of reading with respect to the reference plate executed within one unit of the image forming process can be grasped with high accuracy.

  According to the invention of claim 7, the distribution characteristic of the result obtained by reading the corresponding blank area by the reading unit for each inspection image formed by the image forming unit within one unit of the image forming process is evaluated. Compared to the case where there is no configuration in which the evaluation value is an error of the result obtained by reading the blank area by the reading means for the inspection image whose formation time by the image forming means within one unit of the image forming process is around, There is an effect that the degree and the cause of the variation in the result of reading for the blank area performed in one unit of the image forming process can be grasped with high accuracy.

  According to the eighth aspect of the present invention, an image is formed as compared with a case where the image forming unit further includes an adjusting unit that adjusts conditions used when forming an image based on a result of reading by the reading unit. An effect is obtained that the conditions used for the adjustment are adjusted with high accuracy.

  According to the ninth aspect of the present invention, after the abnormality is detected by the detection unit, the first adjustment instruction that is an instruction to use the latest reading result by the reading unit in the adjustment by the adjustment unit, and the non-latest reading result by the reading unit are displayed. The apparatus further includes a reception unit that receives a second adjustment instruction that is an instruction used for adjustment by the adjustment unit and a re-execution instruction that is an instruction to re-execute reading by the reading unit, and the adjustment unit receives the first adjustment instruction by the reception unit. If accepted, the condition is adjusted based on the latest reading result by the reading means, and if the second adjustment instruction is accepted by the receiving means, the condition is adjusted based on the latest reading result by the reading means, When the reading unit does not have a configuration for re-execution of reading by the reading unit when the re-execution instruction is received by the receiving unit. Compared to improve the convenience of the user, the effect is obtained that.

1 is a schematic configuration diagram illustrating an example of a configuration of an image forming apparatus according to an embodiment. 1 is a schematic configuration diagram illustrating an example of a configuration of a built-in image sensor provided in an image forming apparatus according to an embodiment. 1 is a perspective view showing a part of a built-in image sensor provided in an image forming apparatus according to an embodiment. 1 is a block diagram illustrating an example of a configuration of a control device and its surrounding electrical system in an image forming apparatus according to an embodiment. It is a flowchart which shows an example of the flow of a process of the dispersion | variation determination output process program which concerns on embodiment. It is a continuation of the flowchart shown in FIG. 1 is a schematic diagram illustrating an example of an inspection image to be read by a built-in image sensor provided in an image forming apparatus according to an embodiment. 6 is a schematic diagram illustrating an example of a selection reception screen displayed on a UI panel in the image forming apparatus according to the embodiment. FIG.

  Hereinafter, an example of an embodiment for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus 10 according to an embodiment of the present invention, and FIG. 2 is an example of a built-in image sensor provided in the image forming apparatus 10 according to an embodiment of the present invention. FIG.

(overall structure)
The image forming apparatus 10 according to the present embodiment selectively forms a full-color image and a monochrome image, and is connected to the first housing 10A and the first housing 10A as shown in FIG. A second housing 10B. An image signal processing unit 13 that performs image processing on image data supplied from an external device such as a computer is provided on the upper portion of the second housing 10B. On the other hand, the first special color (V), second special color (W), yellow (Y), magenta (M), cyan (C), and black (K) toners are provided on the upper portion of the first housing 10A. Toner cartridges 14V, 14W, 14Y, 14M, 14C, and 14K are provided.

  Examples of the first special color and the second special color include colors other than yellow, magenta, cyan, and black (including transparency). In the following description, the first special color (V), the second special color (W), yellow (Y), magenta (M), cyan (C), and black (K) are distinguished for each component. Is described with a letter as a symbol followed by any letter of V, W, Y, M, C, or K. The first special color (V), second special color (W), yellow (Y ), Magenta (M), cyan (C), and black (K) are not distinguished, V, W, Y, M, C, and K are omitted.

  Under the toner cartridge 14, six image forming units 16 corresponding to the toners of the respective colors are provided so as to correspond to the toner cartridges 14.

  An exposure device 40 (40V, 40W, 40Y, 40M, 40C) provided for each image forming unit 16 receives the image data subjected to the image processing by the image signal processing unit 13 from the image signal processing unit 13, and An image carrier 18 (18V, 18W, 18Y, 18M, 18C) described later is irradiated with a light beam L modulated in accordance with the image data.

  Each image forming unit 16 includes an image carrier 18 that is rotationally driven in one direction. By irradiating each image carrier 18 with the light beam L from each exposure device 40, an electrostatic latent image is formed on each image carrier 18.

  Around each image carrier 18, a corona discharge (non-contact charging) scorotron charger that charges the image carrier 18 and an electrostatic latent image formed on the image carrier 18 by the exposure device 40 are developed. A developing device that develops with toner, which is an example of an agent, a blade that removes the developer remaining on the image carrier 18 after transfer, and a static eliminator that performs static elimination by irradiating the image carrier 18 after transfer with light. Is provided. The scorotron charger, the developing device, the blade, and the charge eliminating device are arranged in this order from the upstream side to the downstream side in the rotation direction of the image carrier 18 so as to face the surface of the image carrier 18.

  A transfer unit 32 is provided below each image forming unit 16. The transfer unit 32 includes an annular intermediate transfer belt 34 that is in contact with each image carrier 18 and a primary transfer roll 36 that multi-transfers the toner image formed on each image carrier 18 to the intermediate transfer belt 34. Has been.

  The intermediate transfer belt 34 includes a drive roll 38 that is driven by a motor (not shown), a tension applying roll 41 that applies tension to the intermediate transfer belt 34, an opposing roll 42 that faces a secondary transfer roll 62 described below, It is wound around a plurality of winding rolls 44 and is circulated and moved in one direction (counterclockwise direction in FIG. 1) by a drive roll 38.

  Each primary transfer roll 36 is disposed opposite to the image carrier 18 of each image forming unit 16 with the intermediate transfer belt 34 interposed therebetween. The primary transfer roll 36 is applied with a transfer bias voltage having a polarity opposite to the toner polarity by a power supply unit (not shown). With this configuration, the toner image formed on the image carrier 18 is transferred to the intermediate transfer belt 34.

  On the opposite side of the drive roll 38 across the intermediate transfer belt 34, there is provided a removing device 46 that removes residual toner, paper dust and the like on the intermediate transfer belt 34 by bringing the blade into contact with the intermediate transfer belt 34. .

  Below the transfer unit 32, a plurality of recording medium storage units 48 that store a recording medium P as an example of a medium such as paper are provided. Each of the recording medium accommodating portions 48 can be pulled out from the first housing 10A. A delivery roll 52 that feeds the recording medium P from each recording medium container 48 to the transport path 60 is provided above one end side (right side in front view in FIG. 1) of each recording medium container 48.

  In each recording medium accommodating portion 48, a bottom plate 50 on which the recording medium P is placed is provided. The bottom plate 50 is lowered by an instruction from a control means (not shown) when the recording medium accommodating portion 48 is pulled out from the first housing 10A. When the bottom plate 50 is lowered, a space in which the user replenishes the recording medium P is formed in the recording medium accommodating portion 48.

  When the recording medium accommodating portion 48 pulled out from the first housing 10A is attached to the first housing 10A, the bottom plate 50 is raised by an instruction from the control means. As the bottom plate 50 moves up, the uppermost recording medium P placed on the bottom plate 50 and the delivery roll 52 come into contact with each other.

  On the downstream side in the recording medium conveyance direction of the delivery roll 52 (hereinafter sometimes simply referred to as “downstream side”), a separation roll 56 that separates the recording media P delivered from the recording medium accommodating portion 48 one by one. Is provided. A plurality of transport rolls 54 that transport the recording medium P downstream in the transport direction are provided on the downstream side of the separation roll 56.

  A conveyance path 60 provided between the recording medium storage unit 48 and the transfer unit 32 folds the recording medium P sent out from the recording medium storage unit 48 to the left side as viewed from the front in FIG. The second folding portion 60B extends to the transfer position T between the secondary transfer roll 62 and the counter roll 42 so as to be folded back to the right in the front view in FIG.

  The secondary transfer roll 62 is applied with a transfer bias voltage having a polarity opposite to the toner polarity by a power feeding unit (not shown). With this configuration, the toner images of each color that have been multiplex-transferred onto the intermediate transfer belt 34 are secondarily transferred onto the recording medium P that has been transported along the transport path 60 by the secondary transfer roll 62.

  A preliminary path 66 extending from the side surface of the first housing 10 </ b> A is provided so as to join the second folding portion 60 </ b> B of the transport path 60. The recording medium P sent out from another recording medium accommodation unit (not shown) arranged adjacent to the first housing 10 </ b> A can enter the conveyance path 60 through the spare path 66.

  On the downstream side of the transfer position T, a plurality of conveying belts 70 that convey the recording medium P on which the toner image has been transferred toward the second casing 10B are provided in the first casing 10A, and are conveyed to the conveying belt 70. A transport belt 80 that transports the recording medium P to the downstream side is provided in the second housing 10B.

  Each of the plurality of conveyance belts 70 and the conveyance belt 80 is formed in an annular shape and is wound around a pair of winding rolls 72. The pair of winding rolls 72 are respectively arranged on the upstream side and the downstream side in the conveyance direction of the recording medium P, and when one of them is driven to rotate, the conveyance belt 70 (conveyance belt 80) moves in one direction (in FIG. 1). Cycle in the clockwise direction.

  A fixing unit 82 for fixing the toner image transferred onto the surface of the recording medium P to the recording medium P with heat and pressure is provided on the downstream side of the conveyance belt 80.

  The fixing unit 82 includes a fixing belt 84 and a pressure roll 88 disposed so as to contact the fixing belt 84 from below. A fixing unit N is formed between the fixing belt 84 and the pressure roll 88 to fix the toner image by pressurizing and heating the recording medium P.

  The fixing belt 84 is formed in an annular shape and is wound around the drive roll 89 and the driven roll 90. The drive roll 89 faces the pressure roll 88 from above, and the driven roll 90 is disposed above the drive roll 89.

  Each of the driving roll 89 and the driven roll 90 includes a heating unit such as a halogen heater. As a result, the fixing belt 84 is heated.

  As shown in FIG. 1, a conveyance belt 108 is provided on the downstream side of the fixing unit 82 to convey the recording medium P sent from the fixing unit 82 to the downstream side.

  A cooling unit 110 that cools the recording medium P heated by the fixing unit 82 is provided on the downstream side of the conveyance belt 108.

  The cooling unit 110 includes an absorption device 112 that absorbs the heat of the recording medium P, and a pressing device 114 that presses the recording medium P against the absorption device 112. The absorption device 112 is disposed on one side (upper side in FIG. 1) with respect to the conveyance path 60, and the pressing device 114 is disposed on the other side (lower side in FIG. 1).

  The absorption device 112 includes an annular absorption belt 116 that contacts the recording medium P and absorbs the heat of the recording medium P. The absorption belt 116 is wound around a driving roll 120 that transmits a driving force to the absorption belt 116 and a plurality of winding rolls 118.

  A heat sink 122 made of an aluminum material that dissipates heat absorbed by the absorption belt 116 by contacting the absorption belt 116 in a planar shape is provided on the inner peripheral side of the absorption belt 116.

  Further, a fan 128 for removing heat from the heat sink 122 and discharging hot air to the outside is disposed on the back side of the second housing 10B (the back side of the paper surface shown in FIG. 1).

  The pressing device 114 that presses the recording medium P against the absorbing device 112 includes an annular pressing belt 130 that conveys the recording medium P while pressing the recording medium P against the absorbing belt 116. The pressing belt 130 is wound around a plurality of winding rolls 132.

  On the downstream side of the cooling unit 110, there is provided a correction device 140 that conveys the recording medium P and corrects the curl of the recording medium P.

  A built-in image sensor 200 that detects toner density defects, image defects, image position defects, and the like of the toner image fixed on the recording medium P is provided on the downstream side of the correction device 140. Details of the built-in image sensor 200 will be described later.

  On the downstream side of the built-in image sensor 200, a discharge roll 198 that discharges the recording medium P having an image formed on one side thereof to a discharge unit 196 attached to the side surface of the second housing 10B is provided.

  On the other hand, when images are formed on both sides, the recording medium P sent from the built-in image sensor 200 is conveyed to a reversing path 194 provided on the downstream side of the built-in image sensor 200.

  The reversing path 194 includes a branch path 194A that branches from the transport path 60, a paper transport path 194B that transports the recording medium P transported along the branch path 194A toward the first housing 10A, and a paper transport path. A reversing path 194C is provided for turning the recording medium P conveyed along 194B in the reverse direction to switch back and reversing it.

  With this configuration, the recording medium P that is switched back and conveyed by the reverse path 194C is conveyed toward the first housing 10A, and further enters the conveyance path 60 provided above the recording medium container 48, and is transferred to the transfer position. It is sent to T again.

  Next, an image forming process of the image forming apparatus 10 will be described.

  The image data that has been subjected to image processing by the image signal processing unit 13 is sent to each exposure device 40. In each exposure device 40, each light beam L is emitted according to image data, and is exposed to each image carrier 18 charged by a scorotron charger, thereby forming an electrostatic latent image.

  The electrostatic latent image formed on the image carrier 18 is developed by the developing device, and the first special color (V), the second special color (W), yellow (Y), magenta (M), and cyan (C). A toner image of each color of black (K) is formed.

  As shown in FIG. 1, each color toner image formed on the image carrier 18 of each of the image forming units 16V, 16W, 16Y, 16M, 16C, and 16K is composed of six primary transfer rolls 36V, 36W, 36Y, and 36M. , 36C, and 36K, multiple transfer is sequentially performed on the intermediate transfer belt.

  The toner images of the respective colors that have been multiplex-transferred onto the intermediate transfer belt 34 are secondarily transferred onto the recording medium P conveyed from the recording medium accommodating portion 48 by the secondary transfer roll 62. The recording medium P onto which the toner image has been transferred is transported toward the fixing unit 82 provided inside the second housing 10B by the transport belt 70.

  The toner images of the respective colors on the recording medium P are fixed on the recording medium P by being heated and pressurized by the fixing unit 82. Further, the recording medium P on which the toner image is fixed is cooled by passing through the cooling unit 110 and then sent to the correction device 140 to correct the curvature generated in the recording medium P.

  The recording medium P whose curvature is corrected is discharged to the discharge unit 196 by the discharge roll 198 after an image defect or the like is detected by the built-in image sensor 200.

  On the other hand, when an image is formed on a non-image surface where no image is formed (in the case of double-sided printing), after passing through the built-in image sensor 200, the recording medium P is inverted by the inversion path 194, and A toner image is formed on the back surface in the above-described procedure.

  In the image forming apparatus 10 according to the present embodiment, components (image forming units 16V and 16W, exposure devices 40V and 40W, toner cartridges 14V and 14W) for forming images of the first special color and the second special color are used. The primary transfer rolls 36V and 36W) are configured to be attachable to the first housing 10A as additional parts according to the user's selection. Accordingly, the image forming apparatus 10 does not include a part for forming the first special color and second special color images, and the image of any one of the first special color and the second special color. It is good also as a structure which has only the components for forming.

  Next, the built-in image sensor 200 will be described.

  In the following description, the length direction of the image forming apparatus 10 (sub-scanning direction that is the conveyance direction of the recording medium P) is the X direction, the height direction of the apparatus is the Y direction, and the depth direction of the apparatus (main scanning direction) is Z. The direction.

(Basic configuration and function of built-in image sensor)
As shown in FIG. 2, the built-in image sensor 200 as an example of a reading unit includes an irradiation unit 202 that irradiates light toward a recording medium P on which an image is recorded, and a recording medium P that is irradiated from the irradiation unit 202. An image forming unit 208 including an image forming optical system 206 that forms an image on the CCD sensor 204 as an example of a reading unit, and various standards for using the built-in image sensor 200 and calibration are provided. The setting unit 210 is provided. In the present embodiment, the CCD sensor 204 is a primary sensor configured by one-dimensionally arranging light receiving elements (for example, photodiodes) in the Y direction (vertical direction) orthogonal to the main scanning direction and the sub-scanning direction. Although the original image sensor is applied, the present invention is not limited to this, and a two-dimensional image sensor may be used.

  The irradiation unit 202 is disposed on the upper side of the conveyance path 60 of the recording medium P and has a pair of lamps 212. Each of the lamps 212 is a xenon lamp that is elongated in the Z direction, and the length of the irradiation range is larger than the width of the maximum recording medium P to be conveyed. The pair of lamps 212 are arranged symmetrically with respect to the optical axis OA (designed optical axis) that is reflected by the recording medium P and travels toward the image forming unit 208. More specifically, each lamp 212 is arranged symmetrically with respect to the optical axis OA so that the irradiation angle to the recording medium P is 45 ° or more and 50 ° or less.

  Specifically, the pair of lamps 212 are arranged along the conveyance path 60 of the recording medium P, and are recorded on the first lamp 212A and the first lamp 212A arranged on the upstream side in the conveyance direction of the recording medium P. And a second lamp 212B disposed on the downstream side in the conveyance direction of the medium P. The light irradiated from the first lamp 212A and the second lamp 212B is irradiated to the irradiation position D of the transparent window glass 286 on the transport path 60 between the first lamp 212A and the second lamp 212B. It is configured.

  In addition, the imaging optical system 206 includes a first mirror 214 that reflects light guided along the optical axis OA in the X direction (downstream in the conveyance direction of the recording medium P in this embodiment), and the first mirror 214 The second mirror 216 that reflects the reflected light upward, the third mirror 218 that reflects the light reflected by the second mirror 216 to the upstream side in the transport direction of the recording medium P, and the light reflected by the third mirror 218 are CCD A lens 220 that focuses (images) the sensor 204 is configured as a main part. The CCD sensor 204 is arranged on the upstream side in the transport direction of the recording medium P with respect to the optical axis OA.

  The length of the first mirror 214 in the Z direction is larger than the width of the maximum recording medium P. The first mirror 214 to the third mirror 218 reflect the reflected light of the recording medium P incident on the image forming optical system 206 while narrowing (condensing) the light in the Z direction (main scanning direction). It has become. Thus, the reflected light from each part in the width direction of the recording medium P is incident on the substantially cylindrical lens 220.

  The built-in image sensor 200 is configured such that the CCD sensor 204 outputs (feeds back) the imaged light, that is, a signal corresponding to the image density, to the control device 20 (see FIG. 1) of the image forming apparatus 10. . The control device 20 performs processing for correcting an image formed in the image forming unit 16 based on a signal input from the built-in image sensor 200. As an example of the process of correcting the image, correction of the intensity of irradiation light by the exposure apparatus 40 based on a signal input from the built-in image sensor 200, the image formation position, and the like can be given.

  In addition, a light amount diaphragm unit 224 (224L, 224S, 224U)) is provided between the third mirror 218 and the lens 220 in the imaging optical system 206. The light amount diaphragm unit 224 narrows the light amount of light that forms an image on the CCD sensor 204 across the optical path in the Z direction in the Y direction (direction intersecting with the main scanning direction), and adjusts the amount of light diaphragm by operating from the outside. It is configured freely. The light amount stop amount by the light amount stop unit 224 is adjusted so that the light amount imaged on the CCD sensor 204 is equal to or larger than a predetermined amount even if the light emission amount of each lamp 212 changes with time. .

  On the other hand, the setting unit 210 includes a reference roll 226 that is long in the Z direction. The reference roll 226 is directed toward the conveyance path 60 when the image detection of the recording medium P is not performed, and the detection reference surface 228 directed toward the conveyance path 60 when the image detection of the recording medium P is performed. The retraction surface 230, the white reference surface 232, a color reference surface 234 on which a multicolor pattern is formed along the longitudinal direction, and a composite inspection surface 236 on which a plurality of inspection patterns are formed. In this embodiment, the reference roll 226 is formed in a polygonal cylindrical shape having eight or more surfaces formed in the circumferential direction. Only one detection reference surface 228, retraction surface 230, color reference surface 234, and composite inspection surface 236 are provided, and two white reference surfaces 232 are provided.

  The reference roll 226 is configured to switch the surface to be directed to the conveyance path 60 side by rotating around the rotation shaft 226A. The surface of the reference roll 226 is switched by the control circuit 100 provided on the circuit board 262. Moreover, the reference | standard roll 226 is formed in the polygonal cylinder shape more than an octagon, The distance difference with respect to the rotation center of the circumferential direction center of each surface and the corner | angular part between surfaces is suppressed small. Thereby, the corners between the surfaces of the reference roll 226 do not interfere with the irradiation unit 202 while keeping the distance between each surface of the reference roll 226 and the irradiation position (window glass 286) of each lamp 212 small. .

  The detection reference surface 228 has a circumferential width smaller than the other surfaces, and the surfaces on both sides in the circumferential direction are guide surfaces 238 that do not have the above-described functions as the respective references. The detection reference surface 228 is a position reference surface for positioning the detected (read) surface of the conveyed recording medium P at the irradiation position by each lamp 212.

  The retracting surface 230 has a circumferential width larger than that of other surfaces. The retraction surface 230 is a guide surface that guides the recording medium P when the built-in image sensor 200 does not detect the image of the recording medium P, and the distance from the axis of the rotation shaft 226A is more than the detection reference surface 228. It is considered small. Accordingly, when the image detection of the recording medium P by the built-in image sensor 200 is not performed, the distance from the irradiation unit 202 (window glass 286) is larger than when the image detection of the recording medium P by the built-in image sensor 200 is performed. A wide conveyance path is formed.

  The white reference surface 232 is used for calibration of the illumination unit 202 and the imaging optical system 206, and is configured by adhering a reference white film from which a predetermined signal is output from the imaging optical system 206. . The color reference plane 234 is used for calibration of the illumination unit 202 and the imaging optical system 206, and is a film on which a reference color pattern is output in which a predetermined signal corresponding to each color is output from the imaging optical system 206. Is affixed.

  The composite inspection surface 236 is formed by arranging a position adjustment pattern for calibrating the position of the reference roll 226 in the rotation direction (the conveyance direction of the recording medium P), a focus detection pattern, and a depth detection pattern on the same surface. Has been.

  FIG. 3 is a perspective view showing the configuration of the illumination unit 202 and its surroundings according to the present embodiment. As shown in FIG. 3, the illumination unit 202 includes a window glass 286 that transmits the light from the lamp 212 toward the recording medium P. The window glass 286 has a side reference 286 </ b> A that is a white reference provided separately from the reference roll 226. In the window glass 286, the irradiation area irradiated with light from the lamp 212 is an area that overlaps the area through which the image forming area of the recording medium P passes on the setting unit 210, and is formed on the recording medium P on the conveyance path 60. A region (image reading region) determined in advance as a region where the captured image is read by the CCD sensor 204 and a region (side reference region) where the side reference 286A is arranged are configured. The side reference area is adjacent to the image reading area in the main scanning direction (Z direction) and is an area to be read by the CCD sensor 204. Therefore, the reading with respect to the side reference 286A is also performed at the same time when the reading with respect to the image reading area by the CCD sensor 204 is performed. Further, since the side reference area exists at a position that does not overlap with the image (image formation area) formed on the recording medium P, the toner included in the image while the recording medium P passes through the built-in image sensor 200. Adhesion is suppressed. Therefore, even if the side reference 286A is a translucent white plate, the occurrence of a situation in which the reflectance of light decreases due to toner adhering to the side reference 286A is suppressed.

(Schematic configuration of control device)
FIG. 4 is a block diagram showing a schematic configuration of the control device 20 in the image forming apparatus 10 according to the embodiment of the present invention.

  As described above, the control device 20 has a function of correcting an image formed in the image forming unit 16 based on a signal from the built-in image sensor 200. The control device 20 also has a function of controlling calibration of the built-in image sensor 200 (for example, calibration of the CCD sensor 204 described above).

  Specifically, as shown in FIG. 4, the control device 20 includes a CPU 20A, a ROM 20B, a RAM 20C, and an input / output port 20D, each of which passes through a bus 20E such as an address bus, a data bus, and a control bus. Are connected to each other.

  Various programs are stored in the ROM 20B, and various controls are performed by the CPU 20A expanding and executing the programs in the RAM 20C.

  A user interface (UI) panel 30, a lamp 212, and a control circuit 100 are connected to the input / output port 20D. The UI panel 30 includes a touch panel display in which a transmissive touch panel is superimposed on a display, and various types of information are displayed on the display surface of the display, and information and instructions are received when the user touches the touch panel. In the present embodiment, an example in which the UI panel 30 is applied is described. However, the present invention is not limited to this, and a display unit such as a liquid crystal display and an operation unit provided with a numeric keypad, operation buttons, and the like are provided. It is good also as a form provided separately.

  The lamp 212 emits light for reading an image by the built-in image sensor 200, and its on / off (light irradiation or non-irradiation) is controlled by the control device 20.

  As described above, the control circuit 100 controls the switching of the surface of the reference roll 226, and controls the driving of the reference roll rotation motor 22 connected to the control circuit 100 based on an instruction from the control device 20. The control circuit 100 also performs various calibrations of the built-in image sensor 200 according to instructions from the control device 20 (for example, adjustment of upper and lower limit values of the CCD sensor 204 output, correction of illumination distribution, correction of reading values of the CCD sensor 204, etc.). Is supposed to do.

  Next, calibration of the built-in image sensor 200 that is performed when the power is turned on will be described.

  The calibration of the built-in image sensor 200 includes offset and gain adjustment for adjusting the output upper and lower limit values of the CCD sensor 204, shading correction for correcting the illumination distribution of the read image based on the white-reference read image profile, and color. A color calibration on the calibration plate is read and CCD calibration for correcting the reading value of the CCD sensor 204 is performed.

  As an example of these calibration procedures, for example, first, the white reference surface 232 is directed to the conveyance path 60 of the recording medium P, and offset and gain adjustment are performed based on the reading result of the white reference surface 232 of the CCD sensor 204. After that, the light amount distribution in the Z direction (main scanning direction) is corrected (shading correction).

  Subsequently, the composite inspection surface 236 is directed to the conveyance path 60 of the recording medium P, and the detection position by the CCD sensor 204 in the conveyance direction of the recording medium P is adjusted by the position adjustment pattern.

  After the detection position in the conveyance direction of the recording medium P is adjusted, the focus of the CCD sensor 204 is confirmed by the focus detection pattern, and the illumination depth is confirmed by the depth detection pattern.

  Further, the color reference surface 234 is directed to the conveyance path 60 of the recording medium P. The CCD sensor 204 is adjusted so that a predetermined signal is output for each color.

  By the way, in the image forming apparatus 10 according to the present embodiment, the calibration of the built-in image sensor 200 includes an instruction for forming an image on the recording medium P (hereinafter referred to as “image formation instruction”). This is performed every unit and every time an image is formed within one unit of image forming processing. In this case, since the recording medium P on which an image is formed in accordance with the image formation instruction passes above the reference roll 226 via the transport path 60, the calibration using the reference roll 226 is not performed. Then, calibration using the side reference 286A is performed. In order to carry out this calibration with high accuracy, it is necessary to grasp the variation in the results obtained by reading by the CCD sensor 204 within each unit of image forming processing and within one unit of image forming processing with high accuracy. is important. If the variation in the result obtained by reading by the CCD sensor 204 is not within the allowable range, it is necessary to notify the user together with the cause to eliminate the cause.

  Therefore, in the image forming apparatus 10 according to the present embodiment, the variation (for example, density) obtained by reading by the CCD sensor 204 within each unit of image forming processing and within one unit of image forming processing is abnormal. A variation determination output process is performed for determining whether or not there is a variation and determining the cause of variation and outputting a determination result.

  In the image forming apparatus 10 according to the present embodiment, various processes for realizing the variation determination output process are realized by a software configuration. As an example, there is a form in which a program is executed using a computer. However, the present invention is not limited to such a software configuration. Needless to say, it may be realized by a hardware configuration or a combination of a hardware configuration and a software configuration.

  Hereinafter, a case where the CPU 20A of the image forming apparatus 10 according to the present embodiment implements the variation determination output process by executing the variation determination output processing program will be described. In this case, the variation determination output processing program is stored in advance in the ROM 20B, the storage content is stored in a recording medium that can be read by a computer, or distributed via wired or wireless communication means. A form or the like may be applied.

5 and 6 are flowcharts showing the flow of processing of the variation determination output processing program executed by the CPU 20A of the image forming apparatus 10 when the power of the image forming apparatus 10 is turned on. Here, in order to avoid complications, a case where a plurality of inspection images T are formed on the recording medium P according to an image formation instruction will be described. The inspection image T is an image for so-called gradation correction. FIG. 7 shows an example of the inspection image T according to the present embodiment. In the example shown in FIG. 7, the test image T on which the color image has been configured to include a blank space T _S, which is an example of a predetermined area as an area where a color image area T _C and the image formed is not formed shown Has been. Further, here, in order to avoid complications, a result obtained by executing reading by the CCD sensor 204 as data used for calibration is stored in advance in a predetermined storage area ρ of the RAM 20C. explain.

  In step 300 of FIG. 5, after the lamp 212 is turned on, the process proceeds to step 302, and reading by the CCD sensor 204 is executed with the side reference 286A as a reading target. In the next step 304, the result (read result) obtained by reading by the CCD sensor 204 in the process of step 302 is stored in a predetermined storage area α of the RAM 20C, and then the process proceeds to step 306. As an example of the reading result, a physical quantity (for example, a voltage value of an electric signal obtained by photoelectric conversion) corresponding to each received light amount of the image sensor included in the CCD sensor 204 can be cited. In step 304, a physical quantity corresponding to the amount of light received by each image sensor at a position corresponding to the position of the side reference 286A included in the CCD sensor 204 is employed as the reading result. In addition, in a predetermined storage area α of the RAM 20C, a reading result corresponding to a predetermined number of readings (for example, 256 times) is time-sequentially FIFO (First-in First-out) for each image sensor included in the CCD sensor 204. ) Is stored in the form.

  In step 306, an average value and a standard deviation are calculated for the reading results currently stored in the predetermined storage area α of the RAM 20C, and the average value and standard deviation obtained by the calculation are determined in advance in the RAM 20B. After storing in the storage area β, the process proceeds to step 308. Note that the average value and the standard deviation are calculated for each image sensor at a position corresponding to the position of the side reference 286A among the image sensors included in the CCD sensor 204.

  In step 308, it is determined whether or not a predetermined time (for example, 3 minutes) has elapsed as a time during which the lamp 212 is stabilized after the power of the image forming apparatus 10 is turned on. Returns to step 300, but if the determination is affirmative, the routine proceeds to step 310. In step 310, after waiting for an image formation instruction, the process proceeds to step 312, and reading by the CCD sensor 204 is executed with the side reference 286A as a reading target. In the next step 314, the result read by the CCD sensor 204 in the process of step 314 is stored in a predetermined storage area α of the RAM 20C, and then the process proceeds to step 316. In step 316, the average value and the standard deviation are calculated for the reading results stored in the predetermined storage area α of the RAM 20 </ b> C at the present time, and then the process proceeds to step 318, where the image sensor included in the CCD sensor 204 is included. For each of the above, the absolute value of the difference between the standard deviation calculated in the process of step 316 and the standard deviation currently stored in the storage area β is that of the image sensor when the reflected light of the side reference 286A is received. It is determined whether the amount of received light is abnormal or less than a predetermined value. If the determination is negative, the process proceeds to step 320, and it is highly likely that the light emission of the lamp 212 is abnormal. The lamp abnormality alarm information shown is output. An example of the output destination of lamp abnormality alarm information is the UI panel 30. In this case, when the lamp abnormality alarm information is input, the UI panel 30 may display a message indicating that the light emission of the lamp 212 is likely to be abnormal, for example, “the light emission of the lamp 212 is highly likely to be abnormal. Is displayed on the display.

  In the present embodiment, as the process of step 318, a process of determining whether at least one of the absolute values of the standard deviation differences for each of the image sensors is equal to or less than a predetermined value is applied. However, the present invention is not limited to this, and a process of determining whether or not a predetermined number or more of absolute values of differences in standard deviation for each of the image sensors is equal to or less than a predetermined value may be applied. Then, a process of determining whether or not the average value of the absolute values of the standard deviation differences for each of the image sensors is equal to or less than a predetermined value may be applied. Further, instead of the average value, a mode or a median may be applied. In this way, is the evaluation value (in this example, the absolute value of the difference between the standard deviations) that evaluates the distribution characteristic determined in advance as the abnormal distribution characteristic of the reading result related to the side reference 286A equal to or less than a predetermined value? What is necessary is just to determine (whether it is a value determined in advance as a value that does not show abnormal distribution characteristics).

  On the other hand, if an affirmative determination is made in step 318, the process proceeds to step 322, where the average value and standard deviation calculated in the process of step 316 are stored by overwriting in a predetermined storage area β of the RAM 20B. After updating the storage content of the region β, the process proceeds to step 324.

In step 324, control is performed so that a plurality of inspection images T are formed on the recording medium P, and control is performed so that the recording medium P on which the plurality of inspection images T are formed is transported along the transport path 60. I do. Thus, after the plurality of inspection images T are formed on the recording medium P along the sub-scanning direction by the image forming unit 16, the recording medium P on which the plurality of inspection images T are formed is along the conveyance path 60. It is conveyed and eventually reaches a position corresponding to the position of the image reading area of the window glass 286 of the built-in image sensor 200. Here, in step 326, reading by the CCD sensor 204 is executed with one inspection image T and the side reference 286A as reading objects, and in the next step 328, the side reference by the CCD sensor 204 in the processing of step 326 is executed. (Sref) after storing along the results read according to the margin area _{T S} included the reading result and the test image T according to a predetermined storage area δ chronologically the RAM 20C 286A, the process proceeds to step 330. In a predetermined storage area δ of the RAM 20C, the reading results for a predetermined number of readings (for example, five times) are stored in FIFO format in time series for each image sensor.

  In step 330, it is determined whether or not reading by the CCD sensor 204 has been executed for each of all inspection images T formed on the recording paper P. If the determination is negative, the process returns to step 326, but affirmative. If it is determined, the process proceeds to step 332.

In step 332, the present time by a predetermined average value mu _r of such reading result to the side reference 286A stored in the storage area [delta] and the standard deviation sigma _r of RAM 20C, as well as the moment in a predetermined storage area of the RAM 20C [delta] after calculating the average value及mu _p and the standard deviation sigma _p of the reading results related to the margin area T _S stored in, the process proceeds to step 334. Note that the average values μ _r and μ _p and the standard deviations σ _r and σ _p are calculated for each of the image sensors included in the CCD sensor 204.

In step 334, for each of the image pickup element included in the CCD sensor 204, calculates an error _{e r} of reading results related to the side reference 286A. Specifically, an average value mu is the ratio of the standard deviation sigma _r for _{r σ r /} μ _r. In the next step 336, for each of the image pickup element included in the CCD sensor 204, the error e _r calculated in the process at step 334, the received light quantity of the image pickup device at the time of receiving the reflected light of the side reference 286A is abnormal It is determined whether or not an error (predetermined value) is not more than a predetermined value. If the determination is negative, the process proceeds to step 338. In this embodiment, as the process of step 336 was the application of the process of determining whether or less at least one even predetermined value of the error e _r for each of the image pickup device, it is not limited to this, and more predetermined number of errors e _r for each of the image pickup device may be applied to processing for determining whether or not it is less than a predetermined value, in the process at step 334 mean value of the error e _r for each of the calculated image sensor may be applied to processing for determining whether or not it is less than a predetermined value. Further, instead of the average value, a mode or a median may be applied. In this way, whether or not an evaluation value (in this case, error e _r ) that evaluates a distribution characteristic that is predetermined as an abnormal distribution characteristic is a predetermined value or less (abnormal) It is sufficient to determine whether or not the value is predetermined as a value that does not show a significant distribution characteristic.

In step 338, lamp abnormality alarm information indicating that there is a high possibility that the light emission of the lamp 212 is abnormal is output, and then this variation determination output processing program is terminated. An example of the output destination of lamp abnormality alarm information is the UI panel 30. Also in this case, as described above, when the lamp abnormality alarm information is input, the UI panel 30 displays a message indicating that there is a high possibility that the light emission of the lamp 212 is abnormal.

On the other hand, if it is affirmative determination in step 336 proceeds to step 340, for each of the image pickup element included in the CCD sensor 204, calculates an error e _p results read according to the margin region T _S. Specifically, for calculating the σ _{p / μ p} is the proportion of the standard deviation sigma _p to the average value mu _p. In the next step 341, for each of the image sensors included in the CCD sensor 204, an evaluation value E for evaluating the distribution characteristic of the reading result by the CCD sensor 204 within the image formation instruction is calculated. Specifically, the calculated ratio of the error _{e p} calculated in the processing of step 340 to the error _{e r} calculated in the processing of step 334 _{(= e} p / e _r) as the evaluation value E.

Incidentally, the light reflectance of the reflectance and the blank area T _S of the light in the side reference 286A are both about 90%. Therefore, if there is no abnormality such as the lamp 212 and margin area _{T S} relationship between "error _{e p} ≒ error _{e r"} is established. If this relationship is established, the evaluation value E should be within a predetermined error centered on “1”.

Therefore, in the next step 342, among the evaluation values E for each of the imaging device is calculated in the process at step 341, the received light quantity of the image pickup device at the time of receiving the reflected light of the margin area T _S is abnormal It is determined whether or not there is an evaluation value E within a predetermined error range (for example, 0.99 or more and 1.01 or less). If a negative determination is made, the process proceeds to step 344. In the present embodiment, as the process of step 342 described above, a process of determining whether at least one of the evaluation values E for each of the imaging elements is within a predetermined error range is applied. However, the present invention is not limited to this, and a process of determining whether or not a predetermined number or more of the evaluation values E for each of the imaging elements is within a predetermined error range may be applied. You may apply the process which determines whether the average value of the evaluation value E about each of the image pick-up element computed by the process of the said step 341 exists in the predetermined range. Further, instead of the average value, a mode or a median may be applied. Whether Thus evaluation value distribution characteristic of the reading results related to the margin area T _S evaluates the predetermined distribution characteristics as abnormal distribution characteristic (here E as an example) is within the error range is a predetermined (Whether or not it is a value that is predetermined as a value that does not show abnormal distribution characteristics).

In step 344, after outputting the margin abnormality alarm information indicating a high margin area T _S is abnormal (for example, a predetermined amount or more of toner is adhered) may be included in the test image T, step 346 Migrate to An example of the output destination of the margin abnormality alarm information is the UI panel 30. In this case, UI panel 30, the blank error alarm information is input, as a message indicating that there is likely margin area T _S is abnormal, for example, in the blank area toner contained in the "test image T The message “There is a possibility of adhering” is displayed on the display.

Further, after displaying the message indicating that it is likely margin area T _S is abnormal a predetermined time (e.g. 30 seconds), as shown in FIG. 8 as an example, storage area predetermined in RAM20C currently δ Execute calibration using the reading result (latest data) stored in, or perform calibration using the reading result (old data) used in the previous calibration, or read result (calibration) A selection acceptance screen 30A for causing the user to select whether to re-acquire data) is displayed on the display of the UI panel 30. In the example shown in FIG. 8, the push button format includes a menu “Calibration using latest data”, a menu “Calibration using old data”, and a menu “Re-acquire calibration data”. Appears on the display.

  In step 346, if any menu is specified by the user via the touch panel of the UI panel 30 in a state where the selection reception screen 30A is displayed, an affirmative determination is made and the process proceeds to step 348. If no menu is specified by the user via the touch panel of the UI panel 30 while the screen 30A is displayed, a negative determination is made and the routine proceeds to step 350. In step 350, it is determined whether or not a predetermined time (for example, 30 seconds) has elapsed since the execution of the process in step 344 has been completed. If a negative determination is made, the process returns to step 346, while an affirmative determination is made. If this is the case, this variation determination output processing program is terminated.

  In step 348, it is determined whether or not the menu “Calibration with latest data” is specified on the selection acceptance screen 30A. If the determination is affirmative, the process proceeds to step 352, and the storage area δ is currently stored. After updating the stored contents of the storage area ρ by copying the stored reading result and overwriting the predetermined storage area ρ, this variation determination output processing program is terminated.

  On the other hand, if a negative determination is made in step 348, the process proceeds to step 354, where it is determined whether or not the menu “Calibration using old data” is specified on the selection acceptance screen 30 </ b> A, and a negative determination is made. In this case, the menu of “re-acquire calibration data” is designated on the selection acceptance screen 30A, and the process returns to step 310. On the other hand, if the determination is affirmative, the variation determination output processing program is terminated.

As described above, the image forming apparatus 10 according to the present embodiment is obtained by reading the side reference 286A by the CCD sensor 204 for each inspection image formed on the recording medium P within one unit of image forming processing. As an example of the result, when the distribution characteristic corresponding to the received light amount is abnormal, the abnormality is detected by outputting the lamp abnormality alarm information. It is easily understood that there is a high possibility that the light emission of the lamp 212 is abnormal. Further, the distribution characteristic corresponding to the amount of light received is an example of the results obtained are read margins region T _S to test each image formed on the recording medium P in a unit by the CCD sensor 204 of the image forming process Since abnormalities are detected by outputting margin abnormality alarm information when a predetermined distribution characteristic is shown as an abnormal distribution characteristic, the margin area is within one unit of image forming processing compared to the case without this configuration. T _S is that likely to be abnormal is easily grasped. In addition, it is not necessary to limit to the case where the abnormality is detected by the output of the lamp abnormality alarm information or the margin abnormality alarm information, and the abnormality may be detected by determining that the distribution characteristic is abnormal. .

  In the image forming apparatus 10 according to the present embodiment, the distribution characteristic corresponding to the received light amount, which is an example of the result obtained by reading the side reference 286A by the CCD sensor 204 for each unit of the image forming process, is abnormal. When a predetermined distribution characteristic is shown as a distribution characteristic, abnormality is detected by outputting lamp abnormality alarm information. Therefore, compared to the case where this configuration is not provided, the lamp 212 of each unit of image forming processing is detected. It is easily grasped that there is a high possibility that the light emission is abnormal.

In the image forming apparatus 10 according to this embodiment, since the reading timing of the side reference 286A and the blank area T _S is not different, when not having the present structure (e.g. side reference 286A and the blank area T _S at different times Compared to the case of reading), efficient reading is performed, and as a result, the entire processing time is reduced.

  In the above embodiment, since the so-called white level (minimum value of the density range) is used as a criterion for determination, the white plate is applied as the side reference 286A. A blackboard may be applied when using as a criterion for determination.

In the above-described embodiment, an example in which a message indicating that the light emission of the lamp 212 is likely to be abnormal is high based on the reading result of the side reference 286A has been described. In addition to the message indicating that the light emission of the lamp 212 is likely to be abnormal, a message indicating that the side reference 286A may be dirty may be displayed.
Examples of the display form of various messages include audible display using a speaker and permanent visible display using a printer, in addition to visual display using a display. Therefore, one of visible display, audible display, and permanent display may be employed, or a plurality of them may be combined.

In the above embodiment has been described as an example test image T that includes a margin region T _S therein, not limited thereto, may be used test image having a blank area T _S around .

In the above-described embodiment, reading by the CCD sensor 204 has been described as an example. However, the reading is not limited thereto, and reading by, for example, a CMOS image sensor or a CIS (contact image sensor) may be used. reads 286A and blank region T _S, results obtained by reading may be any reading means as long as it is digitally processed inside or outside (below).

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 16 Image forming unit 20 Control apparatus 20A CPU
20C RAM
30 UI panel 200 Built-in image sensor 204 CCD sensor 212 Lamp 286A Side reference

Claims (10)

Image forming means for forming a plurality of inspection images or an image other than the inspection image on a recording medium as a unit of image forming processing using an image including a blank area inside or having a margin area around as an inspection image When,
A reading unit that reads each of the inspection image and the blank area when the plurality of inspection images are formed, and reads a reference plate for image quality adjustment each time the inspection image is read;
When the distribution characteristic of the result obtained by reading the reference plate by the reading unit for each of the inspection images formed by the image forming unit within one unit of the image forming process is abnormal, the reference plate Distribution of results obtained by detecting that the reading result is abnormal and reading the blank area by the reading unit for each inspection image formed by the image forming unit within one unit of the image forming process Detecting means for detecting that the reading result of the blank area is abnormal when the characteristic is abnormal;
An image forming apparatus including: The reading unit further reads the reference plate for each unit of the image forming process,
The detection means further includes that the reading result of the reference plate is abnormal when the distribution characteristic of the result obtained by reading the reference plate by the reading means for each unit of the image forming process is abnormal. The image forming apparatus according to claim 1, wherein an image is detected.   An evaluation value for evaluating a distribution characteristic of a result obtained by reading the reference plate by the reading unit for each unit of the image forming process is obtained by the reading unit with respect to one unit of the image forming process. The image forming apparatus according to claim 2, wherein an error of a result obtained by reading is used.   The reference plate is a position where the inspection image or an image other than the inspection image does not overlap a predetermined region as a region to be read by the reading unit, and the inspection image is read by the reading unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is disposed at a position where the reading unit reads the time. The reading unit is arranged in an illumination unit that illuminates a predetermined reading region as a region from which the inspection image or an image other than the inspection image is read, and the reading region that is illuminated by the lighting unit. Having a reading section for reading the inspection image;
The reading of the blank area and the reference plate by the reading unit within one unit of the image forming process is set to be reading by the lighting unit within one illumination period. The image forming apparatus described in the item.   Evaluation that evaluates distribution characteristics of a result obtained by reading the reference plate by the reading unit together with the blank area corresponding to each of the inspection images formed by the image forming unit within one unit of the image forming process. The value is defined as an error of a result obtained by reading the reference plate by the reading unit with respect to the inspection image whose formation time by the image forming unit is within a unit of the image forming process. The image forming apparatus according to claim 5.   An evaluation value for evaluating a distribution characteristic of a result obtained by reading the corresponding blank area by the reading unit for each inspection image formed by the image forming unit within one unit of the image forming process, 7. The error of a result obtained by reading the blank area by the reading unit for the inspection image whose formation time by the image forming unit is within a unit of image forming processing. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 1, further comprising an adjusting unit that adjusts a condition used when an image is formed by the image forming unit based on a reading result by the reading unit. . After the abnormality is detected by the detection means, a first adjustment instruction that is an instruction to use the latest reading result by the reading means for adjustment by the adjustment means, and an unread reading result by the reading means is adjusted by the adjustment means. A receiving unit that receives a second adjustment instruction that is an instruction to be used and a re-execution instruction that is an instruction to re-execute reading by the reading unit;
The adjusting unit adjusts the condition based on the latest reading result by the reading unit when the receiving unit receives the first adjustment instruction, and the receiving unit receives the second adjustment instruction. And adjusting the condition based on the latest reading result by the reading means,
The image forming apparatus according to claim 8, wherein the reading unit re-executes reading by the reading unit when the re-execution instruction is received by the receiving unit. Image forming means for forming a plurality of inspection images or an image other than the inspection image on a recording medium as a unit of image forming processing using an image including a blank area inside or having a margin area around as an inspection image And reading means for reading each of the inspection image and the blank area when the plurality of inspection images are formed, and reading a reference plate for image quality adjustment each time the inspection image is read. A computer for controlling the image forming apparatus,
When the distribution characteristic of the result obtained by reading the reference plate by the reading unit for each of the inspection images formed by the image forming unit within one unit of the image forming process is abnormal, the reference plate Means for detecting that the reading result is abnormal,
In addition, when the distribution characteristic of the result obtained by reading the blank area by the reading unit for each of the inspection images formed by the image forming unit within one unit of the image forming process is abnormal, the blank A program for functioning as a means for detecting that an area reading result is abnormal.