JP2006253964A - Image reading apparatus and dirt detecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reading apparatus and a dirt detecting method, wherein the adhesion of dirt relating to a reading means for reading a copy is alarmed without causing a trouble to a user. <P>SOLUTION: An image processing part 16 generates shooting data from reference data based on reflected light from a back plate obtained by an image reading part 15. A first control part 10 computes threshold data for determining whether or not each pixel value included in white reference data obtained by the image reading part 15 contains dirt from the shooting data, and compares the threshold data with the white reference data to determine whether or not each pixel value contains dirt. The first control part 10 detects dirt in a predetermined area as one dirt, and when detects each dirt the preset number of times of alarms, makes a voice output of an alarm message from a speaker 28a. Even in the case that the first control part 10 makes the voice output of the alarm message, when a start key is operated, the first control part 10 executes the read processing of a copy by the image reading part 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides an image reading apparatus that detects the position of a stain associated with the reading unit based on an image signal output by reading a reference member provided at a predetermined position by a reading unit that reads an original and outputs an image signal. And a dirt detection method.

  An apparatus such as a copying machine or a facsimile machine is an image formed by an optical system including, for example, a CCD (Charge Coupled Device) line sensor in which a large number of photoelectric conversion elements are arranged in the main scanning direction (a direction orthogonal to the document transport direction). A reading device is provided. In addition, an ADF (Automatic Document Feeder) mechanism is provided, and the originals are separated one by one from the original bundle set on a predetermined mounting table, taken into the apparatus main body, and the taken originals are sequentially read to obtain image signals. Configured devices are widespread.

  Such an image reading apparatus emits light when a document sequentially conveyed by the ADF mechanism passes through a predetermined position, and the reflected light is incident on the CCD line sensor via the condenser lens. Converts an analog signal into an analog signal. Here, when a document is read in a predetermined position where the document is irradiated with light and dirt such as dust or correction liquid on the contact glass between the document and the light source, the sub-scanning direction is included in the read image. A black straight line is formed in the (document transport direction), which reduces the reproducibility of the document image.

In view of this, an image reading apparatus that detects such dirt adhesion and gives a warning to a user has been proposed (see, for example, Patent Document 1). In this image reading apparatus, an image signal for one line is acquired in the main scanning direction by scanning a predetermined white document once with a CCD line sensor, and the pixel value of each pixel based on the obtained image signal is more than a certain level. Is counted as a dirty pixel, and when the count value exceeds a predetermined value, the adhesion of dirt is detected. Further, when the above-described image reading apparatus detects the adhesion of dirt, it prints out an image based on the obtained image signal on a recording sheet, and can notify the user of the detected position of dirt and the state of dirt. .
JP-A-8-331323

  However, as in the case of the image reading apparatus described above, if the configuration is such that a warning is issued immediately when the number of dirty pixels in the image signal for one line in the main scanning direction is equal to or greater than a predetermined number, the audio is particularly effective. In the case of warning, there is a problem that it becomes annoying for the user.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a predetermined area in which stains in a predetermined region are continuously determined based on respective image signals obtained by reading a reference member a plurality of times. It is an object of the present invention to provide an image reading apparatus and a stain detection method that can warn a user for the first time when the number of times is detected, so that the user can be warned of the adhesion of the stain without feeling bothered.

  Another object of the present invention is to provide an image reading apparatus capable of executing various types of processing when a user wants to make a copy or fax transmission in a hurry even when the user is warned of the adhesion of dirt. It is to provide.

  An image reading apparatus according to the present invention is an image reading apparatus that includes a reading unit that reads an original and outputs an image signal, and a reference member provided in an area that can be read by the reading unit; On the basis of an image signal output by reading a reference member, a dirt detecting means for detecting the position of dirt on the reading means, and a count for counting the number of times the dirt detecting means has detected dirt in a predetermined area continuously. And a notifying means for notifying the outside when the counting means counts a predetermined number of times.

  In the present invention, an image reading apparatus including a reading unit that reads a document and outputs an image signal reads the reading based on an image signal output by reading a reference member provided in an area that can be read by the reading unit. The position of the dirt concerning the means is detected. Further, the image reading apparatus counts the number of times that the dirt in the predetermined area has been continuously detected, and when the predetermined number of times is counted, notifies the outside. Therefore, based on the respective image signals obtained by reading the reference member a plurality of times, the user is warned only when the dirt in the predetermined area is continuously detected a predetermined number of times, so that the user does not feel bothered. . Moreover, although the reading position for the same dirt may be shifted depending on the reading accuracy, the dirt in the predetermined area is detected as one dirt, so that it is possible to prevent more than necessary warnings.

  The image reading apparatus according to the present invention is characterized in that the reading unit is configured to read a document even when the counting unit counts a predetermined number of times.

  In the present invention, since the dirt in the predetermined area is continuously counted a predetermined number of times and the document can be read even when the fact is notified to the outside, the user can quickly copy or send a fax. For example, various processes can be executed.

  The stain detection method according to the present invention is a stain detection method in which an image reading apparatus including a reading unit that reads an original and outputs an image signal detects the position of the stain related to the reading unit, and the reading by the reading unit. A step in which the image reading device detects a position of dirt on the reading means based on an image signal output by the reading means reading a reference member provided in an area where the reading is possible, and dirt in a predetermined area Including a step of counting the number of times of continuous detection and a step of notifying the outside when the predetermined number of times is counted.

  In the present invention, dirt in a predetermined area is determined based on each image signal obtained by reading a reference member provided in an area that can be read by a reading unit that reads an original and outputs an image signal. Since the user is warned for the first time when a predetermined number of times are continuously detected, the user does not feel bothered. Further, since the dirt in the predetermined area is detected as one dirt, it is possible to prevent more than necessary warnings.

  According to the present invention, an image reading apparatus including a reading unit that reads an original and outputs an image signal detects a position of a stain on the reading unit based on an image signal output by reading a reference member. Further, the number of times that the dirt in the predetermined area is continuously detected is counted, and when the predetermined number is counted, the fact is notified to the outside. Therefore, based on the respective image signals obtained by reading the reference member a plurality of times, the user is warned only when the dirt in the predetermined area is continuously detected a predetermined number of times, so that the user does not feel bothered. . Further, since the dirt in the predetermined area is detected as one dirt, even if the reading position for the same dirt is shifted, it is possible to prevent an unnecessary warning.

  According to the present invention, since the dirt in the predetermined area is continuously counted a predetermined number of times and the document can be read even when the fact is notified to the outside, the user can quickly copy or If it is desired to send a fax, various processes can be executed.

  Hereinafter, an image reading apparatus according to the present invention will be described in detail based on an embodiment applied to a digital multifunction peripheral (hereinafter referred to as a multifunction peripheral). FIG. 1 is a block diagram illustrating a configuration example of a multifunction peripheral according to the present invention. The multi-function device 1 of the present embodiment includes a first control unit 10 as a control center. The first control unit 10 includes the following hardware units connected via the bus 1a and the serial bus 1b. The operation of the second control unit 23 connected via the control is controlled, and the received operations are sequentially executed according to a series of procedures.

  The bus 1a includes ROM 11, RAM 12, NCU (Network Control Unit) 13, modem 14, image reading unit 15, image processing unit 16, CODEC 17, image memory 18, operation unit 19, display unit 20, recording unit 21, LAN ( A LAN interface 22 for connecting to a (Local Area Network) is connected. Specifically, the first control unit 10 is configured by a CPU (Central Processing Unit), an MPU (Micro Processor Unit), or the like, and implements various software functions according to a control program stored in the ROM 11. The ROM 11 stores in advance various control programs necessary for operating the multifunction device 1 as the image reading apparatus of the present invention. The RAM 12 is configured by SRAM, flash memory, or the like, and temporarily stores data generated when the first control unit 10 executes the control program.

  The modem 14 is a fax modem capable of facsimile communication, and is directly connected to the NCU 13. The NCU 13 is connected to the public telephone line network PSTN. If necessary, the NCU 13 can connect the modem 14 to the public telephone line network PSTN and perform facsimile communication with an external device via the public telephone line network PSTN. It is said.

  The image reading unit 15 is configured by a scanner using a CCD (Charge Coupled Device) or the like, operates as a reading unit that reads a document and acquires image data (image signal), and uses the acquired image data as an image processing unit. 16 output. The image processing unit 16 removes various distortions generated in the illumination system, imaging system, and imaging system included in the image reading unit 15 from the image data output from the image reading unit 15, and performs various color adjustments. Processing is performed, and the processed image data is output to the CODEC 17.

  The CODEC 17 performs encoding processing based on a method such as MH, MR, MMR, JBIG or the like on the image data, performs predetermined encoding processing on the image data acquired from the image processing unit 16, and obtains the obtained image. Data is temporarily stored in the image memory 18. Further, when performing the image forming process based on the image data stored in the image memory 18, the first control unit 10 reads out the image data encoded by the CODEC 17 from the image memory 18 and performs the decoding process by the CODEC 17. After performing, it outputs to the recording part 21.

  The image memory 18 is constituted by a DRAM or a flash memory. The image memory 18 is read from an original by the image reading unit 15 and is subjected to predetermined processing by the image processing unit 16 and the CODEC 17, via the modem 14 and the NCU 13. Image data received by facsimile communication and image data received from an external device via the LAN interface 22 are temporarily stored.

  When the image data stored in the image memory 18 is transmitted by facsimile to an external facsimile machine, the first control unit 10 reads out the image data encoded by the CODEC 17 from the image memory 18, and the modem 14 and the NCU 13 To the external facsimile machine. When transmitting image data stored in the image memory 18 to an external device connected to the LAN, the first control unit 10 reads out the image data encoded by the CODEC 17 from the image memory 18, It transmits to the outside via the LAN interface 22.

  The recording unit 21 is, for example, an electrophotographic printer device, and an image based on image data read from the image memory 18 and decoded by the CODEC 17 is used as a hard copy in A3 vertical, B4 vertical, A4 A recording paper of an optimum size is selected and recorded from recording paper of various sizes such as portrait, B5 landscape, and A5 landscape, or an OHP (Over Head Projector) sheet.

  The operation unit 19 includes a numeric keypad, abbreviated dial keys, a start key, various function keys, and the like necessary for operating the multifunction device 1. The display unit 20 is a display device such as a liquid crystal display (LCD), and the operation state of the multifunction device 1, the display screen to be displayed as the multifunction device 1, information input from the operation unit 19, information to be notified to the user, and the like. Is displayed. In addition, it is also possible to substitute a part or all of the various keys of the operation unit 19 by using the display unit 20 of a touch panel type.

  On the other hand, the second control unit 23 controlled by the first control unit 10 via the serial bus 1b is configured by a CPU, an MPU, or the like, and via the bus 1c, a ROM 24, a RAM 25, an audio decoder 26, an analog front It is connected to the end 27 and the like. The second control unit 23 is configured to reproduce a voice warning message by controlling each of the above-described hardware units in accordance with an instruction from the first control unit 10.

  The ROM 24 stores in advance a control program executed by the second control unit 23 and a warning message such as “Please clean the platen glass” in an appropriate audio data format. The RAM 25 is configured by SRAM, flash memory, or the like, and temporarily stores data generated when the second control unit 23 executes the control program.

  The audio decoder 26 decodes the audio data read from the ROM 24 under the control of the second control unit 23 into an audio signal, and outputs the generated audio signal to the analog front end 27. The analog front end 27 includes a D / A converter (not shown) and the like, converts the digital audio signal input from the audio decoder 26 into an analog signal, and outputs the analog signal to the analog amplifier 28. A speaker 28a is connected to the analog amplifier 28, and an analog audio signal amplified to a predetermined level by the analog amplifier 28 is reproduced and output by the speaker 28a.

  The configuration of the image reading unit 15 in the multifunction machine 1 according to the present embodiment will be described below. FIG. 2 is a diagram illustrating a configuration example of the image reading unit 15. As shown in the schematic perspective view of FIG. 2A, the image reading unit 15 is provided on a rectangular parallelepiped housing 30, a platen cover 31 attached to one side of the upper surface of the housing 30 so as to be openable and closable, and an upper surface of the housing 30. And a rectangular platen glass 32. The image reading unit 15 can perform FBS (Flat Bed Scanner) reading, opens the platen cover 31, places the document with the reading surface of the document facing the platen glass 32, and closes the platen cover 31. Reading is performed with the document stationary on the platen glass 32.

  FIG. 2B is a block diagram showing an example of the internal configuration of the image reading unit 15, and FIG. 2B shows a view seen from the direction indicated by the arrow A in FIG. Inside the housing 30 of the image reading unit 15 is a white fluorescent lamp, a cold cathode tube, or the like, and a light source lamp 34 that irradiates light on the document placed on the platen glass 32, and an optical path l of reflected light from the document. The plate-like first mirror 35, second mirror 37, and third mirror 38 that change the length of the first mirror 35 are in predetermined positions, and the longitudinal direction is parallel to the direction (main scanning direction) indicated by the arrow x in FIG. It is arranged in.

  The light source lamp 34 and the first mirror 35 are moved from the home position to the other end in the direction indicated by the arrow y in FIG. 2A (sub-scanning direction) with one end of the platen glass 32 as the home position. The first carriage 36 is mounted. The second mirror 37 and the third mirror 38 move in the sub-scanning direction y from the center of the platen glass 32 to the other end in response to the movement of the first carriage 36. It is mounted on.

  The housing 30 includes an imaging lens 40 that collects reflected light from the original whose optical path l has been changed by the first mirror 35, the second mirror 37, and the third mirror 38. The CCD line sensor 41 through which the reflected light is incident is also arranged with the longitudinal direction parallel to the main scanning direction x. With this configuration, the image reading unit 15 moves the first carriage 36 and the second carriage 39 in the sub-scanning direction y while moving the first carriage 36 and the second carriage 39 in the sub-scanning direction y. A document image can be read line by line.

  On the other hand, an ADF-type document take-in portion 33 is provided on the upper surface of the platen cover 31, and one document is placed from a bundle of documents set on a predetermined mounting table with the platen cover 31 closed. Separated and captured. The taken document is conveyed from a take-in port 33 a provided in the platen cover 31 to a predetermined reading position, and then discharged from the discharge port 33 b to a discharge tray on the upper surface of the platen cover 31. A platen glass 32a is provided on the upper surface of the housing 30 at a location facing the conveyance path until the document taken in from the take-in port 33a by the document take-in portion 33 is conveyed to the discharge port 33b.

  With such a configuration, the image reading unit 15 is set on a predetermined mounting table in a state where the first carriage 36 and the second carriage 39 are maintained at a position below the platen glass 32a without moving in the sub-scanning direction y. The original line image is read line by line in the sub-scanning direction y by the CCD line sensor 41 with the main scanning direction x as the longitudinal direction for the original sheet separated from the original bundle and passing over the platen glass 32a. be able to.

  In the present embodiment, a back plate (reference member) 42 made of a white plate is disposed at a position facing the platen glass 32 a of the platen cover 31 of the image reading unit 15. Here, the CCD line sensor 41 does not move the first carriage 36 and the second carriage 39 at a predetermined timing, for example, while the image reading unit 15 is not performing the document image reading process, and moves the platen cover 31. Reflected light from the back plate 42 provided on the platen glass 32a is acquired.

  Accordingly, the image reading unit 15 acquires not only original image data based on reflected light from the original but also image data based on reflected light from the back plate 42 (hereinafter referred to as reference data). The reference data acquired by the image reading unit 15 based on the reflected light from the back plate 42 when the light source lamp 34 is turned on is referred to as white reference data, and is emitted from the back plate 42 when the light source lamp 34 is turned off, that is, before the light source lamp 34 is turned on. The reference data acquired by the image reading unit 15 based on the reflected light is referred to as black reference data.

  The image processing unit 16 generates shading data based on the reference data output from the image reading unit 15, and performs shading correction processing based on the generated shading data for the document image data read from the document by the image reading unit 15. To do. The shading data used for the shading correction process performed by the image processing unit 16 includes black data Sb and white data Sw. The black data Sb is an average value of a plurality of lines in the main scanning direction in the black reference data acquired by the image reading unit 15 based on the light from the back plate 42 when the light source lamp 34 is turned off. The white data Sw is an average value of a plurality of lines in the main scanning direction in the white reference data acquired by the image reading unit 15 based on the reflected light from the back plate 42 when the light source lamp 34 is turned on. The shading data generated by the image processing unit 16 is stored in the RAM 12, for example.

  Here, as described above, the first control unit 10 uses the shading data (black data Sb and white data Sw) generated by the image processing unit 16 as a stain detection unit that detects the adhesion of stains on the platen glass 32a. Operate. Specifically, the first control unit 10 reads the document image before reading the document image when the user places a document on a predetermined mounting table and instructs to read the document image by operating the start key. The image reading unit 15 acquires the white reference data Bw based on the reflected light from the back plate 42, and based on the acquired white reference data Bw and the shading data Sb and Sw previously stored in the RAM 12, the platen glass 32a Detect the position of the attached dirt.

  FIG. 3 is a diagram for explaining a stain detection process based on shading data. In this embodiment, a plurality of CCD elements constituting the CCD line sensor 41 are divided into 64 parts, and the position of each CCD element is shown on the horizontal axis x in FIG. 3, and data (pixel data) output from each CCD element is shown. A pixel value of 256 gradations based on the vertical axis L is shown on the vertical axis L. In FIG. 3, the one-dot broken line represents the white data Sw (shading data), the two-dot broken line represents the black data Sb (shading data), and the solid line represents the white reference data Bw acquired at a predetermined timing.

  The first control unit 10 calculates threshold data Limit for determining whether each pixel value included in the white reference data Bw includes dirt based on the white data Sw and the black data Sb. The threshold data Limit is indicated by a broken line in FIG. Accordingly, when each pixel value of the white reference data Bw acquired by the image reading unit 15 at a predetermined timing is smaller than the corresponding threshold value of the threshold data Limit, that is, the pixel value is not changed even though the white back plate 42 is read. When it has a color, the 1st control part 10 judges that this pixel value contains a dirt. Specifically, the first control unit 10 is calculated by substituting each data value of the white data Sw, black data Sb, and white reference data Bw corresponding to each position in the main scanning direction x into the following Equation 1. If the value is equal to or less than the corresponding threshold value of the threshold data Limit, it is determined that the position is dirty.

  (Bw−Sb) / (Sw−Sb) (Formula 1)

  In FIG. 3, three places of first dirt, second dirt, and third dirt are detected. Note that dirt such as dust and dust often has a certain size, and as indicated by the third dirt in FIG. 3, pixel values smaller than each threshold value of the threshold data Limit within a narrow range. Large pixel values may appear alternately, but by considering these as one stain, an unnecessary warning can be prevented.

  Further, when the first control unit 10 detects a stain based on the white reference data Bw as described above, the first control unit 10 stores the detected stain position in the stain history table 12 a of the RAM 12. As shown in FIG. 4, the dirt history table 12a is configured to register dirt data for five dirts with dirt numbers 1 to 5, and the center position for each detected dirt. And the number of times of detection is registered. The center position of the dirt is indicated by any one of 1 to 64 as indicated by the horizontal axis x in FIG. 3, and the number of detections is continuously detected based on the white reference data Bw acquired at a predetermined timing. Shows the number of times. Further, the center position of the dirt does not need to be completely the same. For example, if it is within the interval of 3 with respect to the center position of the previously detected dirt, it is determined that the dirt is substantially the same, and the number of times of detection is determined. Increment by one.

  Accordingly, the first control unit 10 operates as a counting unit that counts the number of times one stain is continuously detected, and is stored in the ROM 24 in advance when the preset number of warnings (for example, 5 times) is continuously detected. The second control unit 23 is controlled so as to output a warning message from the speaker (notification means) 28a, and a warning screen stored in advance in the ROM 11 is displayed on the display unit 20. In this way, by issuing a warning for the first time when the substantially same dirt is detected a plurality of times in succession, the user is not bothered because unnecessary warnings are not performed. The first control unit 10 has a dust flag (not shown) for indicating whether or not to output a warning message and display a warning screen. Is detected, the dust flag is set to 1.

  Even when substantially the same dirt is detected continuously for the number of warnings and a warning message is issued, the user can ignore the warning. For example, a document is placed on a predetermined mounting table. When the start key is pressed, the document reading process by the image reading unit 15 can be started. As a result, when the user wants to make a copy or fax transmission in a hurry, or when the stain on the platen glass 32a is not a concern, various processes can be executed.

  In the present embodiment, when the user once ignores the warning, the first control unit 10 ends the voice output of the warning message and the display of the warning screen, and sets the preset number of times of dirty data deletion (for example, five more times, that is, When the same dirt is detected continuously (total 10 times), the dirt data corresponding to the dirt is deleted from the dirt history table 12a. As a result, when the warning is ignored, the warning is terminated, so that unnecessary continuous warnings can be prevented and the user does not feel bothered.

  Hereinafter, a process for detecting dirt on the platen glass 32a in the multifunction machine 1 having the above-described configuration will be described. FIG. 5 and FIG. 6 are flowcharts showing the procedure of dirt detection processing by the multifunction machine 1 of the present invention. The following processing is executed by the first control unit 10 in accordance with a control program stored in the ROM 11. In the MFP 1 that has been powered on and has been initially prepared, the first control unit 10 performs shading correction by the image processing unit 16 based on the reflected light from the back plate 42 acquired by the image reading unit 15 at a predetermined timing. Shading data used for processing is generated in the image processing unit 16 and stored in the RAM 12.

  In addition, when the user instructs reading of a document image, the first control unit 10 applies light to a document transported on the platen glass 32 a by the document take-in unit 33 or a document placed on the platen glass 32. Before irradiating the light, the light source lamp 34 of the image reading unit 15 is turned on to read the back plate 42 (S1), and white reference data Bw based on the reflected light from the back plate 42 is acquired. Next, the first control unit 10 compares the acquired maximum value of the white reference data Bw and the maximum value of the white data Sw (shading data) stored in the RAM 12 to obtain a coefficient that is comparable. The white reference data Bw is multiplied (S2).

  The first control unit 10 sets its own dust flag to 0 (S3), and starts a process for detecting dirt on the platen glass 32a. Specifically, the first control unit 10 is calculated by substituting the data values of the white data Sw, the black data Sb, and the white reference data Bw corresponding to the respective positions in the main scanning direction x into the above equation 1. It is determined whether or not dirt is detected based on whether or not the value is equal to or less than the corresponding threshold value of threshold data Limit (S4). If dirt cannot be detected (S4: NO), that is, the calculated value is If it is larger than the corresponding threshold value, the process proceeds to step S14.

  If the first control unit 10 determines that dirt has been detected (S4: YES), the center position of the detected dirt is calculated (S5), and a center position within a predetermined range (for example, 3) is calculated from the calculated center position. It is determined whether or not the dirt data on the dirt that has been already registered in the dirt history table 12a (S6). If the first control unit 10 determines that it is not yet registered in the dirt history table 12a (S6: NO), it determines whether the number of dirty data registered in the dirt history table 12a is five. However, if the number of registrations is not 5 (S7: NO), that is, if the number of registrations is 4 or less, the dirt data relating to the dirt at the center position calculated in step S5 is registered in the dirt history table 12a ( S8). If the number of registrations is 5 (S7: YES), the first control unit 10 skips the process of step S8 and shifts the process to step S14.

  On the other hand, when it is determined that the dirt data on the dirt having the center position within the predetermined range from the center position calculated in step S5 is already registered in the dirt history table 12a (S6: YES), the first control unit 10 The number of detections of the corresponding dirt data is incremented by 1 (S9), and it is determined whether or not the incremented number of detections matches a preset number of warnings (S10). If the first control unit 10 determines that they match (S10: YES), it sets the dust flag to 1 (S11), and proceeds to step S14.

  On the other hand, when it is determined that the number of detections does not match the number of warnings (S10: NO), it is determined whether or not the number of detections matches a preset number of dirty data erasures (S12). (S12: YES), the corresponding dirt data is deleted from the dirt history table 12a (S13). When it is determined that the number of detections does not match the number of dirty data deletions (S12: NO), the first control unit 10 skips the process of step S13 and proceeds to step S14.

  Next, the first control unit 10 determines whether or not processing of data corresponding to all positions in the main scanning direction x has been completed (S14), and if not completed (S14: NO), step The process returns to S4, and the stain detection process based on the white reference data Bw for one line in the main scanning direction x is continued. When the first control unit 10 determines that the processing of all the data has been completed (S14: YES), in the dirty data registered in the dirty history table 12a of the RAM 12, the dirty data whose detection count has not been updated is included. It is determined whether or not there is (S15).

  If the first control unit 10 determines that there is dirt data whose number of detections has not been updated (S15: YES), the corresponding control data is deleted from the dirt history table 12a (S16), and the number of detections is not updated. If it is determined that there is no dirty data (S15: NO), the process of step S16 is skipped. Then, the first control unit 10 determines whether or not the dust flag is set to 1 (S17). If it is determined that the dust flag is set to 1 (S17: YES), the second control unit 23 causes the ROM 24 to A warning message stored in advance is output from the speaker 28a as a voice and a warning screen stored in advance in the ROM 11 is displayed on the display unit 20 to warn the user that the platen glass 32a is contaminated (see FIG. S18). If the first control unit 10 determines that the dust flag is not set to 1 (S17: NO), the first control unit 10 ends the process.

  As described above, it is more than necessary to detect a stain having a center position within a predetermined range as substantially the same stain, and issue a warning only when the substantially identical stain is detected a plurality of times in succession. Since this warning is not performed, it is possible to warn of contamination on the platen glass 32a without making the user feel bothersome. Even when a warning message is issued, if the user wants to make a copy or fax transmission quickly, or if the dirt on the platen glass 32a is not a concern, this warning is issued. Can be ignored.

1 is a block diagram illustrating a configuration example of a multifunction machine according to the present invention. It is a figure which shows the structural example of an image reading part. It is a figure for demonstrating the stain | pollution | contamination detection process based on shading data. It is a schematic diagram which shows the structural example of a dirt history table. 6 is a flowchart illustrating a procedure of dirt detection processing by the multifunction peripheral of the present invention. 6 is a flowchart illustrating a procedure of dirt detection processing by the multifunction peripheral of the present invention.

Explanation of symbols

1 MFP (image reading device)
10 1st control part (dirt detection means, counting means)
15 Image reading unit (reading means)
28a Speaker (notification means)
42 Back plate (reference member)

Claims (3)

In an image reading apparatus comprising reading means for reading an original and outputting an image signal,
A reference member provided in an area that can be read by the reading means;
A stain detecting means for detecting the position of the stain associated with the reading means based on the image signal output by the reading means reading the reference member;
Counting means for counting the number of times the dirt detecting means has continuously detected dirt in the predetermined area;
An image reading apparatus comprising: an informing means for informing the outside when the counting means has counted a predetermined number of times.   The image reading apparatus according to claim 1, wherein the reading unit is configured to read a document even when the counting unit counts a predetermined number of times. An image reading apparatus comprising reading means for reading an original and outputting an image signal is a dirt detection method for detecting a position of dirt related to the reading means,
The image reading device detecting a position of dirt on the reading unit based on an image signal output by the reading unit reading a reference member provided in an area that can be read by the reading unit;
Counting the number of times the dirt in the predetermined area has been continuously detected;
And a step of notifying the outside when the predetermined number of times is counted.

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