JP2007166525A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reading apparatus capable of discriminating whether dirt is stuck on an optical member outside a casing or on an optical member inside the casing. <P>SOLUTION: A shading plate 59 within a casing 41 is read, and whether dirt is stuck or not is detected based on a level of an image signal obtained in a CCD 32. Furthermore, a backup plate 58 is read via contact glass 47 outside the casing 41 and whether dirt is stuck or not is detected based on a level of an image signal obtained in the CCD 32. If dirt is detected when the shading plate 59 is read, it is discriminated that dirt is stuck on an optical member (light source 31, mirror 55, 56, 57, image forming lens 54, CCD 32) inside the casing 41 and if dirt is detected when the back plate 58 is read, it is determined that dirt is stuck on an optical member (contact glass 47) outside the casing 41. It is then notified to the user by displaying a message urging the user to perform cleaning. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image reading apparatus that reads an image of a document, and more particularly to an image reading apparatus that detects dirt on an optical member inside or outside a casing.

  In an image reading apparatus such as a copying machine, a facsimile machine, or a multifunction machine, light from a light source is irradiated onto a document, and the reflected light is imaged on a photoelectric conversion element, and the document is based on the imaged light. Read the image. If dirt such as dust, toner, and correction fluid adheres to optical members (contact glass, lenses, mirrors, photoelectric conversion elements, etc.) that constitute the reading optical system of the image reading device, black dots, Black lines appear and image quality deteriorates.

In view of this, there has been proposed an image reading apparatus that automatically detects that such an optical member is contaminated and notifies the user of the detection result to facilitate cleaning (Patent Document 1, etc.). .
JP 2002-320077 A

  When dirt is attached to an optical member outside the housing such as contact glass, the dirt can be removed by user cleaning. However, if dirt is attached to the optical members inside the housing such as lenses, mirrors, photoelectric conversion elements, etc., the dirt cannot be removed without disassembling the housing. Yes, the user needs to contact the service center and request the dispatch of a service person.

  If black dots or black lines appear in the scanned image, the user cannot determine whether the optical member outside the housing is dirty or the optical member inside the housing is dirty, and the housing such as contact glass The user first knows that black spots and black lines remain even after cleaning the external optical member, and that the optical member inside the casing is caused by contamination. Therefore, there is a problem that user operability is poor.

  The present invention has been made in view of such circumstances, and provides an image reading apparatus that can determine whether dirt is attached to the outside or inside of the housing and can improve user operability. For the purpose.

  An image reading apparatus according to the present invention is an image reading apparatus that reads an image of a document using an optical system having an optical member inside a housing including a photoelectric conversion element and an optical member outside the housing. First detection means for detecting dirt based on a signal from the photoelectric conversion element in a state not including an optical member, and based on a signal from the photoelectric conversion element in a state including an optical member outside the housing And a second detection unit that detects dirt, and a determination unit that determines dirt inside the housing and dirt outside the housing according to detection results of the first detection unit and the second detection unit. To do.

  In the image reading apparatus of the present invention, the first detection means detects the stain based on the signal from the photoelectric conversion element using only the optical member inside the housing without including the optical member outside the housing, and The dirt is detected by the second detecting means based on the signal from the photoelectric conversion element using the optical member outside the casing and the optical member inside the casing, and the optical member outside the casing is stained based on the detection results. It is determined by the determination means whether there is a contamination on the optical member inside the housing. That is, when the first detection means detects the dirt, it is determined that the optical member inside the housing is dirty, and the first detection means does not detect the dirt and the second detection means removes the dirt. If it is detected, it is determined that dirt is attached to the optical member outside the housing. Therefore, the user can easily confirm the position where the dirt is attached, and can easily and quickly cope with the position where the dirt is attached, so that the operability for the user is improved.

  The image reading apparatus according to the present invention is characterized in that when the determination unit determines that the inside of the housing is dirty, the image reading device includes a notification unit that notifies an external contact to that effect.

  In the image reading apparatus of the present invention, when it is determined that the optical member inside the casing is contaminated, it is impossible for the user to deal with it. (Service center, network manager, etc.) and request a service person to clean the inside of the housing.

  The image reading apparatus according to the present invention is characterized in that when the determination unit determines that the contamination is outside the housing, the image reading device includes a notification unit that notifies that fact.

  In the image reading apparatus of the present invention, when it is determined that the optical member outside the housing is contaminated, it is possible for the user to deal with it. .

  In the present invention, when a black spot or black line due to the stain of the optical system appears in the read image, it is possible for the user to take measures (stain removal), or to attach the stain to the optical member outside the housing, Since it is possible to determine whether dirt adheres to the optical member inside the housing that cannot be handled by the user, the user can quickly deal with dirt and improve user operability. .

  In the present invention, when it is determined that the inside of the housing is contaminated, notification to that effect is made to the outside contact person so that cleaning can be arranged. it can.

  In the present invention, when it is determined that the dirt is attached to the outside of the housing, the user is notified of this fact and the cleaning is promoted, so that it is possible to quickly perform an appropriate handling process.

  Hereinafter, the image reading apparatus of the present invention will be specifically described based on an embodiment applied to a multi-function peripheral. FIG. 1 is a block diagram showing a configuration of a multifunction machine according to the present invention. The MFP 1 includes a control unit 11, an image reading unit 12, a ROM 13, a RAM 14, an image memory 15, a codec 16, a recording unit 17, an operation unit 18, a display unit 19, a modem 20, an NCU (Network Control Unit) 21, a LAN ( (Local Area Network) interface 22 and the like.

  Specifically, the control unit 11 is configured by an MPU (Micro Processor Unit), and is connected to the above-described hardware units of the multi-function device 1 via a bus. Various software functions are executed in accordance with the stored control program.

  The image reading unit 12 includes a light source 31, a CCD (Charge Coupled Device) 32 as a photoelectric conversion element, an AFE (Analog Front End) 33, an A / D converter 34, an interface 35, a read image processing circuit 36, A reading mechanism control circuit 37, a motor 38, and the like are included. A more detailed configuration and operation of the image reading unit 12 will be described later.

  The ROM 13 stores various software control programs necessary for the operation of the multifunction device 1. The RAM 14 stores temporary data generated when the software is executed. The RAM 14 also has a dirt history table 14a for storing the detected dirt position. The image memory 15 is constituted by a DRAM or the like, and stores image data obtained by reading an image of a document, image data received from a facsimile machine, image data received from an external device via the LAN interface 22, and the like. The codec 16 compresses the image data according to a predetermined compression method, or decompresses the compressed image data according to a predetermined compression method.

  The recording unit 17 is an electrophotographic printer device, and prints out an image corresponding to image data of a document read by the image reading unit 12 and received image data on a sheet. The operation unit 18 includes character keys, numeric keys, abbreviated dial keys, one-touch dial keys, various function keys, and the like necessary for operating the multifunction device 1.

  The display unit 19 is a display device such as a liquid crystal display device or a CRT display. The display unit 19 displays an operation state of the multi-function device 1 including a state where dirt is attached to the reading optical system, or prompts the user to input an operation or a screen for the user. Display a warning screen. The display unit 19 functions as an informing means for notifying the user by displaying a message indicating that the dirt is attached and prompting cleaning when the optical member outside the housing of the multifunction device 1 is detected. To do. In addition, it is also possible to substitute a part or all of the various keys of the operation unit 18 by using the display unit 19 as a touch panel system.

  The modem 20 is connected to a bus and is constituted by a facsimile modem capable of facsimile communication. Similarly, the modem 20 is directly connected to the NCU 21 connected to the bus. The NCU 21 is hardware that performs operations for closing and opening the public line L1 with a public switched telephone network (PSTN), and connects the modem 20 to the PSTN as necessary.

  The LAN interface 22 transmits / receives information to / from other devices via the LAN. In addition, when the LAN interface 22 detects dirt on the optical member inside the housing of the multifunction device 1, a message indicating that the dirt is attached and a request for cleaning is sent to a predetermined external contact address. It functions as a notification means for notifying (service center, network administrator, etc.).

  FIG. 2 is a cross-sectional view illustrating a configuration example of the image reading unit 12. The image reading unit 12 includes a rectangular parallelepiped housing 41, a platen cover 42 attached to one side of the upper surface of the housing 41 so as to be freely opened and closed, and a platen glass 43 provided on the upper surface of the housing 41. Then, FBS (Flat Bed Scanner) scanning is possible, the platen cover 42 is opened, the original is placed with the reading surface of the original facing the platen glass 43, and the platen cover 42 is closed to display the original image. read.

  An ADF (Automatic Document Feeder) type document take-in unit 44 is provided on the upper surface of the platen cover 42, so that one document is taken from a bundle of documents placed on a predetermined mounting table with the platen cover 42 closed. Each sheet is separated and captured. The captured original is conveyed from an intake port 45 provided in the platen cover 42 and is discharged from the discharge port 46 to a discharge tray on the upper surface of the platen cover 42. The image of the document is read at a predetermined reading position during the conveyance. A contact glass 47 is provided on the upper surface of the housing 41 so as to face the reading position.

  An optical system for reading an image of a document is provided inside the housing 41. The optical system includes a light source unit 51, a mirror unit 52, and a reading unit 53. By using the light source unit 51 and the mirror unit 52, the reading unit 53 reads an image of a document. The reading unit 53 includes an imaging lens 54 and a CCD 32, and the reflected light from the document that has passed through the light source unit 51 and the mirror unit 52 is coupled to the CCD 32 as a reading line sensor via the imaging lens 54. Let me image.

  The light source unit 51 includes a light source 31 including an exposure lamp that irradiates light to the platen glass 43 or the contact glass 47 and a mirror 55 that reflects reflected light from the document. The mirror unit 52 has a pair of mirrors 56 and 57 arranged so that the reflection surfaces are orthogonal to each other in order to further change the optical path of the light whose optical path has been changed by 90 ° by the mirror 55 by 180 °. The light source unit 51 and the mirror unit 52 are moved by the motor 38 in parallel with the surface of the platen glass 43.

  The AFE 33 performs various processing such as offset processing and amplification processing on the analog image signal obtained by the CCD 32 (photoelectric conversion element), and the A / D converter 34 converts the analog image signal into a digital image signal. Convert. The read image processing circuit 36 performs various processes such as shading correction, gamma correction, edge enhancement, and binarization on the digital image signal output from the A / D converter 34. The reading mechanism control circuit 37 performs turning on / off control of the light source 31 and rotation control of a motor 38 that drives scanning of the reading optical system.

  A back plate 58 made of a white plate is provided at a position facing the contact glass 47 of the platen cover 42. Further, a shading plate (white reference plate) 59 made of a white plate is provided on the upper inner wall of the housing 41.

  In the image reading unit 12 having such a configuration, the platen glass 43 and the contact glass 47 correspond to optical members outside the housing, and the light source 31, the mirrors 55, 56, and 57, the imaging lens 54, and the CCD 32 (photoelectric conversion element). Corresponds to an optical member inside the housing.

  In the multifunction device 1 of the present invention, the shading plate 59 in the housing 41 is read at the power-on and / or every predetermined period (for example, every day, every week), and the level of the image signal obtained by the CCD 32 is reached. Based on this, the controller 11 detects the presence or absence of dirt. Further, for each reading job (each time the reading start key is pressed), the back plate 58 is read through the contact glass 47, and the control unit 11 determines whether or not dirt adheres based on the level of the image signal obtained by the CCD 32. Is detected.

  When the dirt is detected when the shading plate 59 is read, the control unit 11 attaches dirt to the optical members (the light source 31, the mirrors 55, 56, and 57, the imaging lens 54, and the CCD 32) inside the housing. A message indicating that the dirt has adhered and requesting a cleaning request is sent to a predetermined external contact (service center, network administrator, etc.). On the other hand, when the shading plate 59 is read, dirt is not detected, but when the back plate 58 is read, dirt is detected on the optical member (contact glass 47) outside the housing. Is displayed on the display unit 19 to notify the user of the fact that the dirt adheres and the cleaning is urged. In this way, the control unit 11 includes the first detection unit that detects dirt in a state that does not include an optical member outside the housing, the second detection unit that detects dirt in a state that includes the optical member outside the housing, and the housing. It functions as a judging means for judging whether the dirt is inside the body or outside the casing.

  FIG. 3 is a flowchart showing an operation procedure of processing for detecting contamination of the optical member inside the housing.

  First, after turning on the light source 31 (step S1), the control unit 11 drives the motor 38 to move the light source unit 51 below the shading plate 59 (step S2). Then, the control unit 11 takes in the gradation level values of all the pixels obtained by A / D converting the image signal for one line in the main scanning direction obtained by the CCD 32 (step S3).

  The control unit 11 performs a process of calculating the average value A (i) of the gradation levels of the target pixel (i) and two pixels adjacent to the target pixel (i) on all the pixels (step S4) The process of calculating the average value B (i) of the gradation levels of 100 pixels centered on the target pixel (i) is performed for all the pixels (step S5). Further, the control unit 11 calculates a difference C (i) (= A (i) −B (i)) between the average value A (i) and the average value B (i) (step S6).

  The control unit 11 compares the difference C (i) with a predetermined threshold Th and determines whether or not there is a pixel (i) that satisfies C (i) <Th (step S7). When there is no pixel (i) that satisfies C (i) <Th (S7: NO), the control unit 11 determines that there is no dirt and detects shading data (maximum value Sw of white data). The data is stored in the RAM 14 (step S11), and the operation is terminated.

  On the other hand, when there is a pixel (i) that satisfies C (i) <Th (S7: YES), the control unit 11 determines whether or not the automatic notification function is set (step S8). When the automatic notification function is set (S8: YES), the control unit 11 automatically notifies the service center of dirt adhesion (step S9) and ends the operation. When the automatic notification function is not set (S8: NO), the control unit 11 displays a service man call on the display unit 19 (step S10) and ends the operation.

  4 and 5 are flowcharts showing an operation procedure of processing for detecting dirt on an optical member outside the housing.

  First, after the light source 31 is turned on (step S21), the control unit 11 drives the motor 38 to move the light source unit 51 to the ADF reading position (installation position of the back plate 58) (step S22). Then, the control unit 11 takes in the gradation level value BP (i) of all pixels obtained by A / D converting the image signal for one line in the main scanning direction obtained by the CCD 32 by reading the back plate 58, and the maximum The value BPw is detected and stored in the RAM 14 (step S23).

  Next, the control unit 11 compares the detected maximum value BPw with the maximum value Sw of the white data (shading data) stored in the RAM 14 and obtains a coefficient (Sw / BPw) that is comparable. The corrected gradation level value BPw (i) is obtained by multiplying the gradation level value BP (i) (step S24). The control unit 11 sets its own dirt flag to 0, and performs a process for detecting the presence or absence of dirt (step S25). Specifically, when the black data of the shading data is Sb, the ratio value of (BPw (i) −Sb (i)) / (Sw (i) −Sb (i)) is within a predetermined range. It is determined whether or not there is dirt, and if it is within the predetermined range, it is determined that there is no dirt, and if it is not within the predetermined range, it is determined that there is dirt. When there is no dirt, the value of this ratio is approximately 1, so that the dirt can be detected based on the value of this ratio.

  When the stain is detected (S25: YES), the control unit 11 calculates the center position of the detected stain (step S26), and the stain having the center position within a predetermined range (for example, within 3 pixels) from the calculated center position. It is determined whether or not the data is already registered in the dirt history table 14a (step S27). If not registered yet (S27: NO), the control unit 11 determines whether or not the number of registered dirty data registered in the dirty history table 14a is a predetermined number N (for example, N = 5) ( Step S28) If the number of registrations is not the predetermined number N (S28: NO), that is, if the number of registrations is less than N, the dirt data relating to the center position calculated in S26 is registered in the dirt history table 14a (Step S29). . When the registered number is the predetermined number N (S28: YES), the control unit 11 advances the operation to step S35. If no dirt is detected (S25: NO), the control unit 11 proceeds to step S35 as it is.

  When dirt data having a center position within a predetermined range from the calculated center position is already registered in the dirt history table 14a (S27: YES), the control unit 11 increments the number of times of detection of the corresponding dirt data by 1. (Step S30), it is determined whether or not the incremented number of detections matches a preset number of warnings n1 (Step S31). If they match (S31: YES), the control unit 11 sets the dirt flag to 1 (step S32) and advances the operation to step S35.

  On the other hand, when the number of detections does not match the number of warnings n1 (S31: NO), the control unit 11 determines whether or not the number of detections matches the preset number of dirty data deletions n2 (step S33). If yes (S33: YES), the corresponding dirt data is deleted from the dirt history table 14a (step S34). When the number of detections does not coincide with the number of dirty data deletions n2 (S33: NO), the control unit 11 advances the operation to S35.

  Next, the control unit 11 determines whether or not the processing for all the pixels of the read image has been completed (S35). If the processing has not been completed (S35: NO), the control unit 11 returns the operation to S24, and performs the processing for other pixels. Continue the dirt detection process. When the processing for all the pixels is completed (S35: YES), the control unit 11 determines whether there is dirt data whose number of detections has not been updated in the dirt data registered in the dirt history table 14a of the RAM 14. Judgment is made (step S36).

  When there is dirt data whose number of detections has not been updated (S36: YES), the control unit 11 deletes the corresponding dirt data from the dirt history table 14a (step S37), and there is dirt data whose number of detections has not been updated. When there is not (S36: NO), the control part 11 advances an operation | movement to step S38. Then, the control unit 11 determines whether or not the dirt flag is set to 1 (S38), and if it is set to 1 (S38: YES), the display unit 19 displays a message “Clean screen blinking part. Please display "to notify the user that dirt is adhered to the contact glass 47 and that cleaning is necessary (step S39), and the operation is terminated. When the dirt flag is not set to 1 (S38: NO), the control unit 11 ends the operation as it is.

  In the above-described embodiment of the present invention, the user is notified for the first time when the same dirt is detected a plurality of times in succession, and the user is not inconvenienced because unnecessary notification is not performed. . Further, even when the same dirt is detected continuously for the number of warnings, the user can ignore the notification message. Therefore, when the user wants to perform the process quickly, or when the stain on the contact glass 47 is not concerned, various processes can be executed.

  In the above-described example, the adhesion of the contact glass 47 as the optical member outside the housing has been described. However, the adhesion of the platen glass 43 is similarly performed by closing the platen cover 42 and reading the back surface. be able to.

  In the above-described example, the message is notified to the user by screen display, but the message may be notified to the user by voice output.

1 is a block diagram illustrating a configuration of a multifunction machine according to the present invention. It is sectional drawing which shows the structural example of an image reading part. It is a flowchart which shows the operation | movement procedure of the process which detects the stain | pollution | contamination of the optical member inside a housing | casing. It is a flowchart which shows the operation | movement procedure of the process which detects the stain | pollution | contamination of the optical member outside a housing | casing. It is a flowchart which shows the operation | movement procedure of the process which detects the stain | pollution | contamination of the optical member outside a housing | casing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Multifunction machine 11 Control part 12 Image reading part 13 ROM
19 Display Unit 22 LAN Interface 31 Light Source 32 CCD (Photoelectric Conversion Element)
41 Housing 43 Platen glass 47 Contact glass 54 Imaging lens 55, 56, 57 Mirror 58 Back plate 59 Shading plate (white reference plate)

Claims (3)

  In an image reading apparatus that reads an image of a document using an optical system having an optical member inside a housing including a photoelectric conversion element and an optical member outside the housing, the optical reading device without the optical member outside the housing is included. First detection means for detecting dirt based on a signal from the photoelectric conversion element; and second detection means for detecting dirt based on a signal from the photoelectric conversion element in a state including an optical member outside the housing; An image reading apparatus comprising: a determination unit that determines dirt inside the housing and dirt outside the housing according to detection results of the first detection unit and the second detection unit.   The image reading apparatus according to claim 1, further comprising a notification unit configured to notify an external contact when the determination unit determines that the inside of the housing is dirty.   3. The image reading apparatus according to claim 1, further comprising a notifying unit that notifies that when the determining unit determines that the dirt is outside the casing. 4.

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