JP2020061632A - Image reading device and image forming apparatus - Google Patents

Abstract

To make it possible to check that a contact glass and a rear member are appropriately cleaned.SOLUTION: A cleaning preprocessing unit 81d, when a precondition is established, executes advance notice processing of urging cleaning of a contact glass 17 and a rear member 18. A cleaning post-processing unit 81e, when a completion condition is established after the advance notice processing is executed, executes processing of acquiring post data corresponding to reflected light received by an image sensor 13 under a situation where a document 9 is not present at a reading position P1, processing of determining whether the post-condition is established, and re-notification processing when the post-condition is determined not to be established. The post-condition includes a condition where data satisfying a noise candidate condition in the post data satisfies an improvement condition with respect to data satisfying the noise candidate condition in reference data acquired before the advance notice processing.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image reading apparatus having a function of detecting a noise element on a contact glass and an image forming apparatus including the image reading apparatus.

  The image reading apparatus may perform a document feed type image reading process. The document feeding type image reading process is a process of reading an image from a document conveyed by a document conveying device. The image reading apparatus may be configured as a part of an image forming apparatus such as a copying machine or a multifunction machine.

  In the document feeding type image reading process, when the light source emits light toward the reading position through the contact glass and the document passes through the reading position between the contact glass and the back member, The image sensor receives the reflected light reflected by the document.

  When the light source is turned on under the condition that the document is not present at the reading position, the image sensor receives the reflected light reflected by the back member.

  Further, an AFE (Analog Front End) digitizes the output signal of the image sensor and outputs line image data. The line image data includes a plurality of pixel data representing the densities of a plurality of pixels arranged in the main scanning direction.

  Note that the pixel data may be data representing a higher density as the value thereof is larger, or may be data representing a higher density as the value is smaller.

  The surface of the back member facing the contact glass is a plain surface and is usually a white surface.

  Further, the image reading device, the line image data corresponding to the reflected light when the document is not present at the reading position, and the line image data corresponding to the reflected light passing through the reading position, It is known that a noise element on the contact glass is detected based on the coincidence condition of the positions of the highest density regions in both cases (for example, refer to Patent Document 1).

  The noise element is an image of a shadow caused by paper dust on the contact glass or dirt on the surface of the contact glass.

  By comparing the line image data corresponding to the reflected light reflected by each of the back surface member and the margin of the document, a document noise image such as a black dot existing in the margin of the document is used as the noise element. False detection is avoided.

  When the document feed type image reading process is performed in the presence of the noise element, black streaks extending in the sub-scanning direction are generated in the image read from the document.

JP, 2013-51608, A

  By the way, when the line image data corresponding to the reflected light when the document is not present at the reading position is used for detecting the noise element, if the back surface member is dirty, the noise element is erroneously detected. May be

  That is, when the back member is dirty, there is a high possibility that the dirty portion of the back member and the noise image of the document in the margin of the document are present at the same position in the main scanning direction. Therefore, the original noise image is likely to be erroneously detected as the noise element on the contact glass.

  Therefore, cleaning of the back member is important to avoid erroneous detection of the noise element. Further, cleaning of the contact glass is important for avoiding the generation of the noise element. However, the conventional device does not have a function of confirming whether the back surface member and the contact glass are properly cleaned.

  An object of the present invention is to provide an image reading apparatus and an image forming apparatus including the same, in which it is possible to confirm that the contact glass and the back member arranged along the reading position in the document conveyance path are properly cleaned. .

  An image reading apparatus according to one aspect of the present invention includes a document feeder, a contact glass, a light source, a reading unit, a detection unit, a pre-cleaning processing unit, and a post-cleaning processing unit. The document conveying device conveys a document along a conveyance path that passes through a predetermined reading position. The contact glass is arranged along the reading position, and is formed to extend in the main scanning direction orthogonal to the conveyance direction of the document. The light source is arranged along the reading position so as to face the contact glass, and emits light toward the reading position through the contact glass formed to extend in the main scanning direction. The reading unit includes an image sensor that receives reflected light reflected by the document passing through the back surface member or the reading position, and outputs line image data representing the densities of a plurality of pixels arranged in the main scanning direction. . The detection unit includes reference data, which is the line image data corresponding to the reflected light received by the image sensor when the document is not present at the reading position, and an end portion of the document in the document conveyance direction. The document edge data, which is the line image data corresponding to the reflected light received by the image sensor while passing through the reading position, is acquired, and the reference data and the document edge data are predetermined. A glass noise element, which is a noise element on the contact glass, is detected by determining the coincidence status of pixel data positions that satisfy the noise candidate condition. The noise handling unit executes a predetermined noise handling process when the glass noise element is detected. The pre-cleaning processing unit executes a pre-notification process that prompts cleaning of the contact glass and the back member when a predetermined pre-condition is satisfied. The post-cleaning processing unit executes predetermined post-cleaning processing when a predetermined end condition is satisfied after the pre-notification processing is executed. The post-cleaning process is a process of acquiring post-data that is the line image data corresponding to the reflected light received by the image sensor under a situation where the document is not present at the reading position, and a predetermined post-process. And a re-notification process for urging re-cleaning of one or both of the contact glass and the back member when it is determined that the post-condition is not satisfied. . The post-condition is the pixel data satisfying the noise candidate condition in the post-data, and one or more post-noise candidate data is the reference data in the reference data acquired before the pre-notification process is executed. It includes a condition that a predetermined improvement condition based on one or more pieces of prior noise candidate data which is pixel data satisfying the noise candidate condition is satisfied.

  An image forming apparatus according to another aspect of the present invention includes the image reading device, and a printing device that forms an image on a sheet based on the plurality of line image data obtained by the image reading device.

  According to the present invention, it is possible to provide an image reading apparatus and an image forming apparatus including the same, in which it is possible to confirm that the contact glass and the back member arranged along the reading position in the document transport path are properly cleaned. become.

FIG. 1 is a configuration diagram of an image forming apparatus including the image reading apparatus according to the first embodiment. FIG. 2 is a configuration diagram of a main part of the image reading apparatus according to the first embodiment. FIG. 3 is a block diagram showing the configuration of the control unit in the image forming apparatus. FIG. 4 is a flowchart showing an example of a procedure of noise detection / correspondence processing in the image reading apparatus according to the first embodiment. FIG. 5 is a flowchart showing an example of the procedure of cleaning management processing in the image reading apparatus according to the first embodiment. FIG. 6 is a flowchart showing an example of the procedure of cleaning management processing in the image reading apparatus according to the second embodiment. FIG. 7 is a flowchart showing an example of the procedure of the recleaning management process in the image reading apparatus according to the second embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are examples of embodying the present invention and do not limit the technical scope of the present invention.

[First Embodiment]
The image reading apparatus 1 according to the first embodiment sequentially reads a plurality of line images from the document 9 and sequentially outputs a plurality of line image data Ld1 representing the read plurality of line images (see FIG. 1).

  In this embodiment, the image reading apparatus 1 is configured as a part of the image forming apparatus 10 (see FIG. 1).

  As shown in FIG. 1, the image forming apparatus 10 includes an image reading device 1 and a printing device 2. Further, the image forming apparatus 10 includes an operation device 8a, a display device 8b, and a control device 8.

  The operation device 8 a, the display device 8 b, and the control device 8 are a part of the image reading device 1 and a part of the printing device 2.

  The printing device 2 executes print processing for forming an image on the sheet 90. For example, the printing device 2 can execute the printing process based on the line image data Ld1 obtained by the image reading device 1.

  The printing device 2 includes a sheet conveying device 3 and an image forming unit 4. The sheet conveyance device 3 conveys the sheet 90 along the sheet conveyance path 300. The image forming unit 4 executes the print process on the sheet 90 conveyed by the sheet conveying device 3.

  In the example shown in FIG. 1, the image forming unit 4 executes the electrophotographic printing process. In the image forming unit, the charging device 42 charges the surface of the drum-shaped photoconductor 41, and the optical scanning unit 43 writes an electrostatic latent image on the surface of the photoconductor 41.

  Further, the developing device 44 develops the electrostatic latent image into a toner image, the transfer device 45 transfers the toner image onto the sheet 90, and the fixing device 47 fixes the toner image onto the sheet 90. Further, the drum cleaning device 46 removes the toner remaining on the surface of the photoconductor 41.

  The image reading device 1 includes a light source 11, a light guide unit 12, an image sensor 13, a carriage moving device 14, an ADF (Automatic Document Feeder) 15, a platen glass 16, a contact glass 17, a back member 18, and the like. The ADF 15 is an example of a document feeder.

  The light source 11, the light guide section 12, and the image sensor 13 are formed so as to extend in the main scanning direction D1. 1 and 2, the depth direction toward the drawings is the main scanning direction D1.

  The light emitted from the light source 11 is applied to the document 9, and the light guide section 12 guides the reflected light reflected by the document 9 to the image sensor 13. The image sensor 13 receives the reflected light and detects the light amount of the reflected light. Further, the image sensor 13 outputs a line image signal La1 indicating the detection result of the light amount of the reflected light.

  In the example shown in FIG. 1, the image sensor 13 is a CCD (Charge Coupled Device) type sensor. The light guide section 12 also includes a first mirror 12a, a second mirror 12b, and a condenser lens 12c.

  The first mirror 12a is supported by the first carriage 110 together with the light source 11, and guides the reflected light to the second mirror 12b. The second mirror 12b is supported by the second carriage 120 and guides the reflected light reflected by the first mirror 12a to the condenser lens 12c.

  The condenser lens 12c condenses the reflected light on the light receiving portion of the image sensor 13.

  The carriage moving device 14 moves the first carriage 110 and the second carriage 120 at different speeds along the sub-scanning direction D2. The sub-scanning direction D2 is a direction orthogonal to the main scanning direction D1.

  The ADF 15 is incorporated in a document cover 100 in which the upper surfaces of the platen glass 16 and the contact glass 17 are openably and closably supported. The ADF 15 operates when the document cover 100 is closed, that is, when the document cover 100 covers the contact glass 17.

  As shown in FIGS. 1 and 2, the ADF 15 includes a document transport path 150, a supply tray 151, a document pickup device 152, a plurality of transport roller pairs 153, and a discharge tray 154.

  The document transport path 150 is a transport path for the document 9, and is formed along a curved path from an entrance facing the supply tray 151, a predetermined reading position P1 to an exit facing the discharge tray 154. ing.

  The contact glass 17 is arranged below the reading position P1 along the reading position P1. The back member 18 is arranged above the reading position P1 and along the reading position P1. That is, the back surface member 18 is arranged along the reading position P1 so as to face the contact glass 17. The contact glass 17 and the back member 18 are formed so as to extend in the main scanning direction D1.

  The lower surface of the back member 18 facing the contact glass 17 is a plain surface and is usually a white surface. The contact glass 17 has a flat plate shape, and the lower surface of the back member 18 is a flat surface.

  The reading position P1 is a region between the upper surface of the contact glass 17 and the lower surface of the back member 18 that has a predetermined width in the sub-scanning direction D2.

  The document pickup device 152 sends out the documents 9 placed on the supply tray 151 one by one to the document conveyance path 150. The plurality of pairs of transport rollers 153 transport the document 9 along the document transport path 150, and further discharge the document 9 from the document transport path 150 to the discharge tray 154.

  The image reading apparatus 1 selectively executes a flatbed type image reading process and a document feed type image reading process.

  The flatbed type image reading process is a process of reading an image from the original 9 placed on the platen glass 16. In the flatbed image reading process, the carriage moving device 14 moves the first carriage 110 and the second carriage 120 below the platen glass 16 along the sub-scanning direction D2.

  The light from the light source 11 scans the original 9 on the platen glass 16 by the movement of the first carriage 110. Further, the image sensor 13 sequentially receives the reflected light reflected at different positions on the original 9 in the sub-scanning direction D2.

  On the other hand, the document feed type image reading process is a process of reading an image from the document 9 conveyed by the ADF 15. In the document feed type image reading process, the carriage moving device 14 holds the first carriage 110 at a position below the reading position P1, and the ADF 15 conveys the document 9 along the document conveying path 150.

  When the first carriage 110 is located below the reading position P1, the light source 11 emits light that passes through the contact glass 17 toward the reading position P1.

  The original 9 is conveyed at the reading position P1 along the sub-scanning direction D2, so that the light from the light source 11 is scanned onto the original 9 passing through the reading position P1.

  When the first carriage 110 is located below the reading position P1, the image sensor 13 receives the reflected light reflected by the back member 18 when the document 9 is not present at the reading position P1. Further, the image sensor 13 receives the reflected light reflected by the document 9 passing through the reading position P1 when the document 9 passes through the reading position P1.

  Then, the image sensor 13 outputs a line image signal La1 indicating the detected light amount of the reflected light reflected by the back surface member 18 or the original 9. While the document 9 is passing the reading position P1, the image sensor 13 sequentially outputs the line image signal La1 corresponding to the reflected light reflected by different regions of the document 9 in the sub-scanning direction D2.

  As shown in FIG. 2, the image reading apparatus 1 further includes a first document sensor 18a and a second document sensor 18b. The first document sensor 18a detects the document 9 on the supply tray 151. The second document sensor 18b detects the document 9 at a position upstream of the reading position P1 in the document transport path 150 in the transport direction of the document 9.

  The operation device 8a is a device that receives a human operation, and includes, for example, operation buttons and a touch panel. The display device 8b is a device that displays information, and includes, for example, a panel display device such as a liquid crystal display unit.

  The control device 8 executes various types of data processing, control of the image reading device 1 and control of the printing device 2.

  As shown in FIG. 3, the control device 8 includes an AFE 80, a CPU 81, a RAM (Random Access Memory) 82, a secondary storage device 83, a print engine 84, and the like. The control device 8 also includes a communication device (not shown) that communicates with other devices.

  The CPU 81 is a processor that executes a computer program stored in the secondary storage device 83 to execute processing relating to control of the image reading apparatus 1 and the printing apparatus 2 and other data processing.

  For example, the CPU 81 operates as the reading control unit 81a by executing the computer program (see FIG. 3). The reading control unit 81a controls the control target device of the image reading apparatus 1 to cause the control target device to execute the image reading process. The control target device includes a light source 11, a carriage moving device 14, an image sensor 13, and an AFE 80.

  The reading controller 81a controls the reading device 81a when a predetermined reading start operation is performed on the operating device 8a in a situation where the original 9 on the supply tray 151 is not detected by the first original sensor 18a. The target device is caused to execute the flatbed image reading process.

  On the other hand, the reading control unit 81a, when the original 9 on the supply tray 151 is detected by the first original sensor 18a, when the reading start operation is performed on the operation device 8a, The device is caused to execute the document feed type image reading process.

  The RAM 82 is a computer-readable volatile storage device. The RAM 82 temporarily stores the computer program executed by the CPU 81 and the data output and referenced in the process of the CPU 81 executing the computer program.

  The secondary storage device 83 is a computer-readable non-volatile storage device. The secondary storage device 83 can store the computer program and various data. For example, one or both of a hard disk drive and an SSD (Solid State Drive) is adopted as the secondary storage device 83.

  The AFE 80 converts the line image signal La1 into digital line image data Ld1 (see FIGS. 1 and 3). The line image data Ld1 includes a plurality of pixel data representing the densities of a plurality of pixels arranged in the main scanning direction D1.

  The image sensor 13 and the AFE 80 receive the reflected light reflected by the document 9 passing through the back surface member 18 or the reading position P1 and output line image data Ld1 representing the densities of a plurality of pixels arranged in the main scanning direction D1. It is an example of a reading unit.

  The image sensor 13 outputs the line image signal La1 after a certain processing time has elapsed after receiving the reflected light. Therefore, at the timing when the line image signal La1 is output from the image sensor 13 and the timing when the line image data Ld1 is output from the AFE 80, the reflected light corresponding to the line image signal La1 and the line image data Ld1 is the image sensor. It is delayed by a predetermined time with respect to the timing of receiving light at 13.

  A CIS (Contact Image Sensor) unit including the CMOS type image sensor 13 and the condenser lens 12c may be employed instead of the CCD type image sensor 13 and the light guide section 12. In this case, the CIS is supported by the first carriage 110 and the second carriage 120 is omitted.

  The CPU 81 operates as the detection unit 81b and the noise handling unit 81c by executing the computer program (see FIG. 3).

  The detection unit 81b executes a process of detecting the glass noise element in a noise detection / correspondence process described later.

  The detection unit 81b corresponds to the position of the high density pixel in the line image data Ld1 corresponding to the reflected light reflected by the back surface member 18 and the reflected light reflected at the end of the document 9 passing through the reading position P1. The position of the high density pixel in the line image data Ld1 is compared.

  Then, when the positions of the high-density pixels of both of them coincide with each other, the detection unit 81b detects the high-density pixels of which the positions are coincident with each other as a pixel of the glass noise element. The details of the process of detecting the glass noise element will be described later.

  The noise handling unit 81c executes a predetermined noise handling process when the glass noise element is detected. A specific example of the noise handling process will be described later.

  Usually, the end portion of the document 9 is a margin portion. By comparing the line image data Ld1 corresponding to the reflected light reflected by each of the back surface member 18 and the margin of the document 9, the image of the dirty portion of the back surface member 18 is erroneously detected as the glass noise element. Is avoided.

  When the document feed type image reading process is performed in the presence of the glass noise element, a black streak extending along the sub-scanning direction D2 occurs in the image read from the document 9.

  By the way, when the line image data Ld1 corresponding to the reflected light when the document 9 is not present at the reading position P1 is used for detecting the glass noise element, if the rear surface member 18 is dirty, the glass noise element is detected. It may be erroneously detected.

  That is, when the back surface member 18 is soiled, there is a high possibility that the soiled area on the back surface member 18 and the noise image in the blank portion of the document 9 are present at the same position in the main scanning direction D1. Therefore, the original noise image is likely to be erroneously detected as the noise element on the contact glass.

  Therefore, it is important to clean the back member 18 in order to avoid erroneous detection of the glass noise element. Further, cleaning of the contact glass 17 is important for avoiding the generation of the glass noise element. However, the conventional device does not have a function of confirming whether the back surface member 18 and the contact glass 17 are properly cleaned.

  The image reading device 1 executes a cleaning management process described later. As a result, the image reading apparatus 1 can confirm that the contact glass 17 and the back surface member 18 arranged along the reading position P1 in the document feeding path 150 are properly cleaned.

  The cleaning management process is a process premised on the image reading apparatus 1 having a function of executing the noise detection / correspondence process.

[Noise detection / corresponding processing]
Next, an example of the procedure of the noise detection / correspondence processing will be described with reference to the flowchart shown in FIG.

  The detection unit 81b and the noise handling unit 81c perform the noise detection / handling process when the document feed type image reading process is performed. That is, the noise detection / correspondence process is executed when the document 9 is conveyed by the ADF 15.

  Specifically, when the reading start operation is performed on the operation device 8a under the situation where the original 9 on the supply tray 151 is detected by the first original sensor 18a, the detection unit 81b and the noise countermeasure are performed. The unit 81c starts the noise detection / correspondence processing shown in FIG.

  In the following description, S101, S102, ... Represent identification codes of a plurality of steps in the noise detection / correspondence processing.

<S101>
In the noise detection / correspondence process, first, the detection unit 81b acquires reference data from the AEF 80. The reference data is line image data Ld1 corresponding to the reflected light received by the image sensor 13 when the document 9 is not present at the reading position P1.

  Specifically, the detection unit 81b receives the light from the image sensor 13 between the time when the reading start operation is performed on the operation device 8a and the time when the document 9 is detected by the second document sensor 18b. The line image data Ld1 corresponding to the reflected light is acquired as the reference data.

  For example, when a plurality of originals 9 are sequentially conveyed by the ADF 15, the detection unit 81b acquires the reference data only once before the first original 9 reaches the reading position P1.

  On the other hand, when a plurality of documents 9 are sequentially conveyed by the ADF 15, the detection unit 81b may acquire the reference data for each document 9.

  In the above case, the detection unit 81b operates between the state in which the original 9 is detected by the second original sensor 18b and the state in which the original 9 is not detected until the next original 9 is detected by the second original sensor 18b. The line image data Ld1 corresponding to the reflected light received by the image sensor 13 is acquired as the new reference data.

<S102>
Further, the detection unit 81b executes a process of identifying the reference noise candidate data in the reference data. The reference noise candidate data is one or more pixel data that satisfy a predetermined noise candidate condition in the reference data.

  For example, the noise candidate condition is a condition that the pixel data represents a density higher than a predetermined threshold density. The value of the data representing the threshold density is a constant value, a value obtained by multiplying a representative value of a plurality of pixel data in the reference data by a predetermined coefficient, or a predetermined constant for the representative value. For example, the value obtained by addition. The representative value is an average value or a median value.

<S103>
Further, the detection unit 81b acquires document edge data from the AEF 80. The document edge data is line image data Ld1 corresponding to the reflected light received by the image sensor 13 while the edge of the document 9 in the document transport direction passes through the reading position P1.

  Specifically, the detection unit 81b corresponds to the reflected light received by the image sensor 13 when a predetermined edge arrival time has elapsed from the time when the document 9 is detected by the second document sensor 18b. The line image data Ld1 is acquired as the document edge data.

  In the present embodiment, the document edge data is line image data Ld1 corresponding to the reflected light reflected by the leading edge of the document 9. In this case, the edge arrival time is the time required for the leading edge of the document 9 to be conveyed from the position of the second document sensor 18b to the reading position P1. The leading end of the document 9 is often a blank space.

  It is also conceivable that the detection unit 81b acquires the two line image data Ld1 corresponding to the reflected light reflected on the leading edge and the trailing edge of the document 9 as the document edge data.

  Further, when a plurality of documents 9 are sequentially conveyed by the ADF 15, the detection unit 81b acquires the document edge data each time the edge of the document 9 reaches the reading position P1.

  In steps S101 and S103, the reference data and the document edge data corresponding to the reflected light received by the image sensor 13 while the light source 11 is turned on are acquired.

<S104>
Further, as in step S102, the detection unit 81b executes a process of identifying the document noise candidate data in the document edge data. The original noise candidate data is one or more pixel data satisfying the noise candidate condition in the original edge data.

<S105>
Next, the detection unit 81b executes a process of detecting a glass noise element which is a noise element on the contact glass 17 by determining the matching state of the positions of the reference noise candidate data and the original noise candidate data.

  Specifically, when the reference noise candidate data and the original noise candidate data whose pixel positions in the main scanning direction D1 are coincident with each other are specified, the detector 81b determines the glass noise element at the coincident pixel positions. Is determined to exist.

  The reference noise candidate data may include pixel data of the glass noise element and pixel data of a dirty portion of the back surface member 18. On the other hand, the original noise candidate data may include the pixel data of the glass noise element and the pixel data of the original noise image in the margin of the original 9, but the pixel data of the dirty portion of the back surface member 18 Is not included.

  If there are few dirty parts on the back member 18, it is unlikely that the position of the pixel data of the dirty part of the back member 18 and the position of the pixel data of the original noise image in the margin of the original 9 match. .

  By comparing the line image data Ld1 corresponding to the reflected light reflected by each of the back surface member 18 and the margin portion of the document 9, the document noise image such as a black dot existing in the margin portion of the document 9 becomes the glass noise. False detection as an element is avoided.

  Then, when the glass noise element is detected, the detection unit 81b shifts the processing to step S106, and when the glass noise element is not detected, ends the noise detection / correspondence processing.

<S106>
In step S106, the noise handling unit 81c executes the noise handling process and ends the noise detection / handling process.

  For example, the noise handling process is a carriage position changing process of changing the position of the first carriage 110 in the sub-scanning direction D2 by controlling the carriage moving device 14.

  Due to the carriage position changing process, there is a high possibility that the first carriage 110 is moved to a position where the glass noise element is not detected.

  For example, the noise handling unit 81c changes the position of the first carriage 110 from a position on the upstream side in the document transport direction to a position on the downstream side. As a result, the line image of the document 9 read at the reading position P1 before the first carriage 110 is moved can be read again at the position after the first carriage 110 is moved without re-conveying the document 9. You can

  However, the noise handling unit 81c executes control to change the position of the first carriage 110 within the width of the area of the reading position P1 between the upper surface of the contact glass 17 and the lower surface of the back member 18.

  On the other hand, it is also conceivable that the noise handling process is a noise data correction process of correcting pixel data of a target pixel corresponding to the detected position of the glass noise element in a plurality of document read data.

  The plurality of document read data is a plurality of line image data Ld1 corresponding to the reflected light received by the image sensor 13 while the entire document 9 passes through the reading position P1.

  In the noise data correction processing, the noise handling unit 81c corrects the pixel data of the target pixel to data based on the pixel data of other pixels. For example, the noise handling unit 81c corrects the pixel data of the target pixel to data obtained by interpolation calculation based on the pixel data of the adjacent pixel adjacent to the target pixel in the main scanning direction D1.

  When the number of originals 9 to be read is one, the detection unit 81b and the noise handling unit 81c execute the processes of steps S101 to S106 only once.

  On the other hand, when there are a plurality of originals 9 to be read, the detecting unit 81b executes the processes of steps S101 and S102 only for the first original 9 or for each of the plurality of originals 9. Further, the detection unit 81b and the noise handling unit 81c execute the processes of steps S103 to S106 for each of the plurality of originals 9.

[Cleaning management processing]
Next, an example of the procedure of the cleaning management process will be described with reference to the flowchart shown in FIG. The cleaning management process is a process for prompting cleaning of the contact glass 17 and the back surface member 18 and confirming the cleaning status.

  The CPU 81 also operates as the pre-cleaning processing unit 81d and the post-cleaning processing unit 81e by executing the computer program (see FIG. 3). The pre-cleaning processing unit 81d and the post-cleaning processing unit 81e execute the cleaning management process.

  For example, the pre-cleaning processing unit 81d and the post-cleaning processing unit 81e execute the cleaning management process before or at the end of the document feeding type image reading process each time the document feeding type image reading process is executed. .

  The secondary storage device 83 stores the reference data DT1 in advance before the cleaning management process is executed (see FIG. 3). The reference data DT1 is data serving as a reference for the line image data Ld1 corresponding to the reflected light received by the image sensor 13 when the document 9 is not present at the reading position P1.

  In the following description, S201, S202, ... Represent identification codes of a plurality of steps in the cleaning management process.

<S201>
In the cleaning management process, the pre-cleaning processing unit 81d acquires the reference data DT1 from the secondary storage device 83.

<S202>
Further, the pre-cleaning processing unit 81d executes the process of identifying the reference noise candidate data in the reference data, as in step S102 of FIG. The reference noise candidate data is one or more pixel data satisfying the noise candidate condition in the reference data.

<S203>
Further, the cleaning pretreatment unit 81d acquires the reference data acquired in step S101 of FIG. 4 as the preliminary data. That is, the preliminary data is line image data Ld1 corresponding to the reflected light received by the image sensor 13 under the condition that the document 9 is not present at the reading position P1.

  The advance data is the reference data acquired from the AFE 80 before the advance notification process executed in step S206 described below is executed.

  When the cleaning management process is executed at the start of the document feed type image reading process, the preliminary data is the reference data acquired before the first document 9 reaches the reading position P1. . When the cleaning management process is executed at the end of the document feed type image reading process, the preliminary data is acquired before the first document 9 or the last document 9 reaches the reading position P1. It is the said reference data which are made.

<S204>
Further, the pre-cleaning processing unit 81d executes the process of identifying the preliminary noise candidate data in the preliminary data, as in step S102 of FIG. The preliminary noise candidate data is one or more pixel data that satisfies the noise candidate condition in the preliminary data.

  The preliminary noise candidate data is the same as the reference noise data specified in step S102 of FIG. The detection unit 81b that executes the processes of steps S101 and S102 in FIG. 4 may also serve as the pre-cleaning processing unit 81d that executes the processes of steps S203 and S204.

<S205>
Next, the cleaning pretreatment unit 81d determines whether or not a predetermined precondition is satisfied. The pre-condition is a condition that represents a standard that requires cleaning of the contact glass 17 and the back member 18. Specifically, the cleaning pretreatment unit 81d determines whether or not the precondition is satisfied by determining whether or not the precondition data satisfies a predetermined deterioration condition based on the reference data DT1. To determine.

  The pre-cleaning processing unit 81d determines that the pre-condition is satisfied when it is determined that the pre-data satisfies the deterioration condition, and determines that the pre-condition is not satisfied otherwise.

  The deterioration condition is that the number of the preliminary noise candidate data specified from the preliminary data increases beyond a predetermined change amount with respect to the number of the reference noise candidate data specified from the reference data. It includes the first deterioration condition that The amount of change is represented by the number or ratio.

  Note that, as described above, the preliminary data and the preliminary noise candidate data are the same as the reference data and the reference noise candidate data obtained in steps S101 and S102 of FIG.

  Further, it is possible that the deterioration condition further includes the following second deterioration condition. The second deterioration condition is a condition that the representative value of the preliminary data has changed to a high density side by exceeding a predetermined allowable change width with respect to the representative value of the reference data.

  In the above case, it may be considered that the deterioration condition is a condition of the logical sum of the first deterioration condition and the second deterioration condition. The representative value is an average value or a median value.

  Then, the pre-cleaning processing unit 81d moves the process to step S206 when determining that the pre-condition is satisfied, and ends the cleaning management process otherwise.

<S206>
In step S206, the cleaning pretreatment unit 81d executes a preliminary notification process that prompts the user to clean the contact glass 17 and the back surface member 18. After that, the pre-cleaning processing unit 81d shifts the processing to step S207.

  For example, the cleaning preprocessing unit 81d causes the display device 8b to display a cleaning notification screen including a cleaning message prompting the user to clean the contact glass 17 and the back surface member 18 in the advance notification process.

  The cleaning notification screen further includes a cleaning end operation message that prompts the user to perform a predetermined cleaning end operation on the operation device 8a after the cleaning is completed.

<S207>
In step S207, the post-cleaning processing unit 81e determines whether a predetermined ending condition is satisfied. The post-cleaning processing unit 81e moves the process to step S208 when it is determined that the ending condition is satisfied, and otherwise repeats the process of step S207.

  In the present embodiment, the end condition includes a first end condition that the cleaning end operation is performed on the operating device 8a.

  Furthermore, it is also possible that the termination condition includes a second termination condition that a predetermined maximum waiting time has elapsed since the precondition was satisfied. In this case, the end condition is a condition of the logical sum of the first end condition and the second end condition.

<S208>
In step S208, the post-cleaning processing unit 81e acquires the posterior data from the AFE 80 and shifts the processing to step S209.

  The post data is the line image data Ld1 corresponding to the reflected light received by the image sensor 13 under the condition that the original 9 is not present at the reading position P1 after the termination condition is satisfied.

  In step S208, the posterior data corresponding to the reflected light received by the image sensor 13 while the light source 11 is turned on is acquired.

<S209>
In step S209, the post-cleaning processing unit 81e executes the process of identifying the posterior noise candidate data in the posterior data, and shifts the process to step S210. The posterior noise candidate data is one or more pixel data satisfying the noise candidate conditions in the posterior data.

<S210>
In step S210, the post-cleaning processing unit 81e determines whether a predetermined post-condition is satisfied. The post-conditions are conditions indicating that the contact glass 17 and the back surface member 18 have been sufficiently cleaned. The post-cleaning processing unit 81e shifts the processing to step S211 when it is determined that the post-condition is satisfied, and shifts the processing to step S212 when it is determined that the post-condition is not satisfied.

  The post-conditions include a first post-condition that the post-noise candidate data satisfies a predetermined improvement condition based on the pre-noise candidate data.

  For example, the improvement condition is that the number of the posterior noise candidate data specified from the posterior data is a predetermined change amount with respect to the number of the prior noise candidate data specified from the prior data. It includes the first improvement condition that it is decreasing beyond. The amount of change is represented by the number or ratio.

  Further, it is possible that the improvement condition further includes the following second improvement condition. The second improvement condition is a condition that the representative value of the posterior data has changed to the low density side by exceeding a predetermined required change width with respect to the representative value of the preliminary data.

  In the above case, it is possible that the improvement condition is a condition of a logical product of the first improvement condition and the second improvement condition. The representative value is an average value or a median value.

  It is also possible that the postconditions include the following second postconditions. The second posterior condition is a condition that the number of the posterior noise candidate data specified from the posterior data is less than a predetermined upper limit noise number.

<S211>
In step S211, the post-cleaning processing unit 81e executes a process of updating the reference data DT1 stored in the secondary storage device 83 to the post data when the post condition is satisfied. Then, the post-cleaning processing unit 81e ends the cleaning management process.

  Usually, the back member 18 is a synthetic resin member. It is unavoidable that the back surface member 18 is slightly soiled as the operating time of the image reading apparatus 1 elapses.

  Therefore, if the initial reference data DT1 is not updated, a situation may occur in which the advance notification process of step S206 cannot be executed at an appropriate timing.

  On the other hand, by the process of step S211, the reference data DT1 is updated to the posterior data obtained in a state where the contact glass 17 and the back surface member 18 are properly cleaned. That is, the reference data DT1 is updated to the data corresponding to the actual condition of the back member 18 that has been properly cleaned.

  Then, in the next cleaning management process, the pre-cleaning processing unit 81d determines whether or not the reference data satisfies the deterioration condition based on the updated reference data DT1 stored in the secondary storage device 83. By determining, it is determined whether the precondition is satisfied (step S205). As a result, the advance notification process of step S206 can be executed at an appropriate timing.

  Since the platen glass 16 is made of a glass material, scratches, irremovable stains, discoloration, etc. are unlikely to occur.

<S212>
In step S212, the post-cleaning processing unit 81e determines whether or not the number of times the post-condition is satisfied in the cleaning management process currently being executed is less than a predetermined upper limit number.

  Then, the post-cleaning processing unit 81e shifts the process to step S213 when determining that the number of times the post-condition is satisfied is less than the upper limit number, and shifts the process to step S214 otherwise.

<S213>
In step S213, the post-cleaning processing unit 81e executes a re-notification process that prompts the user to re-clean the contact glass 17 and the back surface member 18, and repeats the processes from step S207.

  For example, the post-cleaning processing unit 81e causes the display device 8b to display a recleaning notification screen including a recleaning message prompting the user to reclean the contact glass 17 and the back surface member 18 in the re-notification process.

  The recleaning notification screen further includes a recleaning end operation message urging the user to perform the end operation on the operation device 8a after the end of the recleaning.

<S214>
On the other hand, in step S214, the post-cleaning processing unit 81e executes a predetermined error notification process and ends the cleaning management process.

  For example, the post-cleaning processing unit 81e causes the display device 8b to display a message prompting the user to contact the customer support center in the error notification process.

  As described above, the pre-cleaning processing unit 81d executes the pre-notification process when the predetermined pre-condition is satisfied.

  Further, the post-cleaning processing unit 81e executes the processes of steps S208 to S214 when the ending condition is satisfied after the advance notification process is executed. The processing of steps S208 to S214 is an example of a predetermined post-cleaning processing.

  That is, the post-cleaning processing unit 81e executes a process of acquiring the post data (step S208) and a process of determining whether or not the post condition is satisfied (step S210). Further, the post-cleaning processing unit 81e executes the re-notification process when it is determined that the post-condition is not satisfied (step S213).

  By executing the cleaning management process, the image reading apparatus 1 can confirm that the contact glass 17 and the back member 18 have been properly cleaned.

[Second Embodiment]
Next, an image reading apparatus according to the second embodiment will be described with reference to FIGS. The image reading device according to the present embodiment has the same configuration as the image reading device 1 according to the first embodiment.

  In the image reading device according to the present embodiment, the pre-cleaning processing unit 81d and the post-cleaning processing unit 81e are similar to the pre-cleaning processing unit 81d and the post-cleaning processing unit 81e of the image reading device 1 in the procedure shown in FIG. The cleaning management process is executed.

  Hereinafter, differences between the image reading apparatus according to the present embodiment and the image reading apparatus 1 will be described.

  As shown in FIG. 6, the image reading apparatus according to the present embodiment is different from the image reading apparatus 1 in that the process of step S213 in the cleaning management process shown in FIG. 5 is replaced with the process of step S215. It is only that.

  The process of step S215 is a recleaning management process executed by the post-cleaning processing unit 81e. The recleaning management process is executed when the postcondition is not satisfied. In the present embodiment, the processes of steps S208 to S212 and S214 and the re-cleaning management process are examples of post-cleaning processes.

[Recleaning management processing]
An example of the procedure of the recleaning management process will be described below with reference to the flowchart shown in FIG. 7. In the following description, S301, S302, ... Represent identification codes of a plurality of steps in the recleaning management process.

<Step S301>
In the re-cleaning management process, first, the post-cleaning processing unit 81e executes the transport notification process and shifts the process to step S302. The conveyance notification process is a process of prompting the user to set a blank sheet on the ADF 15 and to start the reading operation, which is an operation of operating the ADF 15.

  For example, in the conveyance notification process, the post-cleaning processing unit 81e includes a blank sheet reading notification including a message that prompts the user to place a blank sheet on the supply tray 151 and then perform the reading start operation on the operating device 8a. The screen is displayed on the display device 8b.

<Step S302>
In step S302, the post-cleaning processing unit 81e determines whether or not a predetermined reading start condition is satisfied, and when it is determined that the reading start condition is satisfied, the process proceeds to step S303.

  The reading start condition is that the reading start operation is performed on the operation device 8a under the condition that the first original sensor 18a detects that the blank sheet is placed on the supply tray 151 as the original 9. The condition is that

  The first document sensor 18a and the second document sensor 18b do not have a function of identifying whether or not the document 9 is the blank sheet.

<Step S303>
In step S303, the post-cleaning processing unit 81e operates the ADF 15. As a result, the ADF 15 conveys the blank sheet. After that, the post-cleaning processing unit 81e shifts the processing to step S304.

<Step S304>
In step S304, the post-cleaning processing unit 81e acquires blank page data from the AEF 80 and shifts the processing to step S305.

  The blank sheet data is line image data Ld1 corresponding to the reflected light received by the image sensor 13 while the blank sheet is passing through the reading position P1.

  The blank sheet data does not include information about the stain on the back surface member 18. Further, since the white paper that does not include a noise image such as a black dot is used, the white paper data includes only the information regarding the presence / absence of stains on the platen glass 16.

  For example, the post-cleaning processing unit 81e causes the line image data Ld1 corresponding to the reflected light received by the image sensor 13 when the edge arrival time has elapsed from the time when the blank sheet is detected by the second document sensor 18b. Is acquired as the blank page data.

<Step S305>
In step S305, the post-cleaning processing unit 81e executes a process of identifying glass noise candidate data in the blank sheet data, and shifts the process to step S306. The glass noise candidate data is one or more pixel data satisfying the noise candidate condition in the blank sheet data.

<Step S306>
In step S306, the post-cleaning processing unit 81e determines whether or not the blank sheet data satisfies a predetermined acceptance condition.

  In the present embodiment, the permissible condition includes a first permissive condition that the number of the glass noise candidate data specified from the blank sheet data is less than a predetermined permissible number.

  It is also possible that the permissive conditions further include the following second permissive conditions. The second permissible condition is that the density represented by the representative value of the blank sheet data is lower than a predetermined permissible density.

  In the above case, it is considered that the allowable condition is a condition of a logical product of the first allowable condition and the second allowable condition. The representative value is an average value or a median value.

  Then, the post-cleaning processing unit 81e shifts the process to step S307 when determining that the blank sheet data satisfies the allowable condition, and shifts the process to step S308 otherwise.

<Step S307>
In step S307, the post-cleaning processing unit 81e executes a first re-notification process that prompts the user to re-clean the back surface member 18, and ends the re-cleaning management process.

  For example, the post-cleaning processing unit 81e causes the display device 8b to display a back surface member re-cleaning notification screen including a back surface member re-cleaning message that prompts the user to re-clean the back surface member 18 in the first re-notification process.

  The rear surface member recleaning notification screen further includes the recleaning end operation message prompting the user to perform the cleaning end operation on the operation device 8a after the end of the recleaning.

<Step S308>
On the other hand, in step S308, the post-cleaning processing unit 81e executes the second re-notification process that prompts the user to re-clean the contact glass 17 and ends the re-cleaning management process.

  For example, the post-cleaning processing unit 81e causes the display device 8b to display a glass recleaning notification screen including a glass recleaning message prompting the user to reclean the contact glass 17 in the second re-notification process.

  The glass recleaning notification screen further includes the recleaning end operation message that prompts the user to perform the cleaning end operation on the operation device 8a after the end of the recleaning.

  In the second re-notification process, the post-cleaning processing unit 81e may execute a process of prompting the user to re-clean both the contact glass 17 and the back surface member 18.

  The first re-notification process and the second re-notification process are re-notification processes that prompt re-cleaning of one or both of the contact glass and the back member when it is determined that the post-condition is not satisfied. Is an example.

  In the present embodiment, the post-cleaning processing unit 81e determines whether or not the reason why the post-conditions are not satisfied is that stains remain on the contact glass 17 by the processes of steps S301 to S306. .

  According to the present embodiment, the recleaning notification process is executed by distinguishing which of the contact glass 17 and the back member 18 should be the target of recleaning. As a result, the user can instruct an appropriate response.

[Application example]
Hereinafter, application examples of the image reading device 1 will be described.

  Also in this application example, the post-cleaning processing unit 81e executes the cleaning management process shown in FIG. At that time, the post-cleaning processing unit 81e further executes the processes of steps S301 to S305 shown in FIG. 7 after executing the process of step S208 and before executing the process of step S210.

  That is, in this application example, the post-cleaning processing unit 81e executes the conveyance notification process after the post-data is acquired, and then executes the process of acquiring the blank sheet data while the ADF 15 is in operation ( (See steps S301 and S304 in FIG. 7).

  Further, the post-cleaning processing unit 81e determines in step S210 of FIG. 5 whether the following third post-condition is satisfied as one of the post-conditions.

  The third post-condition is a condition that the blank sheet data satisfies the allowable condition (see step S306 in FIG. 7). In this case, it can be considered that the post-condition is a condition of a logical product of the first post-condition and the third post-condition. It is also conceivable that the postcondition is a condition of a logical product of the first postcondition, the second postcondition, and the third postcondition.

  In this application example, the processes of steps S208 to S214 and the processes of steps S301 to S305 of FIG. 6 are examples of predetermined post-cleaning processes.

  According to this application example, the respective conditions of the platen glass 16 and the back surface member 18 are discriminated and determined, and the post-condition is determined more appropriately.

1: image reading device 2: printing device 3: sheet conveying device 4: image forming unit 8: control device 8a: operating device 8b: display device 9: original document 10: image forming device 11: light source 12: light guide unit 12a: first 1 mirror 12b: 2nd mirror 12c: condensing lens 13: image sensor 14: carriage moving device 16: platen glass 17: contact glass 18: back member 18a: first document sensor 18b: second document sensor 41: photoconductor 42 : Charging device 43: Optical scanning unit 44: Developing device 45: Transfer device 46: Drum cleaning device 47: Fixing device 81: CPU
81a: read control section 81b: detection section 81c: noise handling section 81d: pre-cleaning processing section 81e: post-cleaning processing section 82: RAM
83: secondary storage device 84: print engine 90: sheet 100: document cover 110: first carriage 120: second carriage 150: document transport path 151: supply tray 152: document pickup device 153: transport roller pair 154: discharge tray 300: sheet conveying path D1: main scanning direction D2: sub scanning direction DT1: reference data La1: line image signal Ld1: line image data P1: reading position

Claims (9)

A document transport device that transports a document along a transport path that passes through a predetermined reading position,
A contact glass disposed along the reading position and extending in a main scanning direction orthogonal to the document transport direction;
A back surface member that is arranged along the reading position so as to face the contact glass and that extends in the main scanning direction;
A light source that emits light passing through the contact glass toward the reading position;
A reading unit that includes an image sensor that receives reflected light reflected by the document that is passing through the back surface member or the reading position, and that outputs line image data that represents the density of a plurality of pixels arranged in the main scanning direction;
Reference data, which is the line image data corresponding to the reflected light received by the image sensor when the document is not present at the reading position, and an end of the document in the document conveyance direction passes through the reading position. Document edge data, which is the line image data corresponding to the reflected light received by the image sensor, and satisfies predetermined noise candidate conditions in the reference data and the document edge data. A detector that detects a glass noise element that is a noise element on the contact glass by determining the coincidence status of pixel data positions,
A cleaning pre-processing unit that executes a prior notification process that prompts cleaning of the contact glass and the back member when a predetermined pre-condition is satisfied,
A post-cleaning processing unit that executes a predetermined post-cleaning process when a predetermined termination condition is satisfied after the pre-notification process is executed,
The post-cleaning treatment is
A process of acquiring post-data that is the line image data corresponding to the reflected light received by the image sensor under a situation where the document is not present at the reading position;
A process of determining whether or not a predetermined post-condition is satisfied,
When it is determined that the post-condition is not satisfied, a re-notification process that prompts re-cleaning of one or both of the contact glass and the back surface member,
The post-condition is the pixel data satisfying the noise candidate condition in the post-data, and one or more post-noise candidate data is the reference data in the reference data acquired before the pre-notification process is executed. An image reading apparatus including a condition of satisfying a predetermined improvement condition based on one or more pieces of prior noise candidate data which are pixel data satisfying a noise candidate condition. The precondition is satisfied by the cleaning preprocessing unit determining whether the reference data satisfies a predetermined deterioration condition based on standard data stored in a storage device in advance. Whether or not,
The image reading apparatus according to claim 1, wherein the post-cleaning process further includes a process of updating the reference data stored in the storage device to the post-data when the post-condition is satisfied. The post-cleaning treatment is
When it is determined that the post-condition is not satisfied, a conveyance notification process that prompts an operation of setting a blank sheet on the document conveyance device and operating the document conveyance device,
After the conveyance notification process is performed, while the document conveying apparatus is in operation, the blank sheet data that is the line image data corresponding to the reflected light received by the image sensor while the blank sheet is passing the reading position is displayed. And the process to get
Further comprising a process of determining whether or not the blank data satisfies a predetermined tolerance condition,
The re-notification process is
A first re-notification process that is executed when it is determined that the blank data satisfies the acceptance condition and that prompts re-cleaning of the back member;
The image reading device according to claim 1, further comprising a second re-notification process that is executed when it is determined that the blank data does not satisfy the permissible condition and that prompts re-cleaning of the contact glass. . The post-cleaning treatment is
Transport notification processing that prompts an operation of setting a blank sheet on the document transport device and operating the document transport device after the post data is acquired,
After the conveyance notification process is performed, while the document conveying apparatus is in operation, the blank sheet data that is the line image data corresponding to the reflected light received by the image sensor while the blank sheet is passing the reading position is displayed. Further including a process of acquiring,
The postconditions are:
The image reading apparatus according to claim 1, further comprising a condition that the blank sheet data satisfies a predetermined allowable condition.   The image reading device according to claim 1, wherein the end condition includes a condition that a predetermined cleaning end operation is performed on an operation device that receives a human operation.   The image reading device according to claim 1, further comprising a noise handling unit that performs a predetermined noise handling process when the glass noise element is detected. A carriage moving device that moves a carriage supporting the light source and the mirror that guides the reflected light to the image sensor or the image sensor in a sub-scanning direction orthogonal to the main scanning direction,
The image reading device according to claim 6, wherein the noise handling process is a process of changing a position of the carriage in the sub-scanning direction by controlling the carriage moving device.   The noise handling processing detects the detected glass in a plurality of document reading data which are a plurality of the line image data corresponding to the reflected light received by the image sensor while the entire document passes through the reading position. The image reading apparatus according to claim 6, which is a process of correcting pixel data of a pixel of interest corresponding to a position of a noise element to data based on pixel data of another pixel. An image reading apparatus according to any one of claims 1 to 8,
An image forming apparatus, comprising: a printing apparatus that forms an image on a sheet based on the line image data obtained by the image reading apparatus.

Images