JP2006148677A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader which surely and quickly allows a user to perform operator maintenance by clearly indicating the position of a foreign matter on an original mount glass for the user by an indicating means disposed near the original mount glass to prompt to clean up it. <P>SOLUTION: In order to eliminate the image failure due to a foreign matter (dust such as paper powder) on the image, a means for indicating the position of foreign matter on a glass is provided near the glass so that a user surely removes it. Concretely, among light emitting elements arranged in one line in the scanning direction, only one light emitting element located as the same position as the foreign matter is lit to indicate the position of foreign matter position on the glass, thus intuitively notifying the user of the foreign matter position on the glass. This clearly indicates the glass cleaning position for the user and hence it is expectable that the user surely and quickly cleans. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus for a color copying machine, and more particularly to cleaning assistance for foreign matter adhering to a platen glass that causes a streak image generated when a document being conveyed is read, or so-called flow reading is performed. .

  As a method for reading a document in an image reading apparatus, there is a method of performing so-called flow reading in which a document being conveyed by a document conveying device is read in a state in which a scanning unit composed of an illumination unit, a mirror, and the like is fixed.

  Since the scanning means is fixed in the flow reading, the original reflected light always passes through the same position of the original table glass and is incident on a light receiving element such as a line sensor.

  Therefore, when foreign matter such as dust adheres on the platen glass, the reflected light from the original is blocked at that position, and the reflected light from the original is not incident on the light receiving element. There is a problem that streaks occur in the sub-scanning direction.

  Therefore, the following has been proposed as a method for solving the generation of streaks.

  In order to eliminate image streaks due to foreign matter on the platen glass, the presence or absence of foreign matter is detected before reading the document or at the position where the platen glass is scanned between the paper. In some cases, a message prompting the cleaning of the glass surface is displayed on a display unit such as an operation unit panel after the document reading job is completed, so that the user actively removes foreign matter (see, for example, Patent Document 1).

Another method is to detect dust on the glass during scanning and correct image streaks caused by dust, present the correction location of the image, let you know that the image has been processed, and There is one that aims to provide an image processing apparatus that prompts the user to remove the factor (see, for example, Patent Document 2).
JP 2001-144901 A JP 2002-368932 A

  However, since the method of Patent Document 1 eliminates the cause of image defects, it can be an effective solution for image streaks due to foreign matter. However, it is often difficult to visually confirm the foreign matter that causes the streak image, and the removal of the foreign matter is insufficient only by urging the glass to be cleaned.

  In Patent Document 2, when image streaks are corrected by foreign matter, the streak image is printed out, thereby notifying the user of the position of the foreign matter on the glass and prompting cleaning. Print output is required to indicate the cleaning position.

  Accordingly, the object of the present invention is to clearly show the position of the foreign matter on the platen glass that causes streak images to the user by the display means arranged in the vicinity of the platen glass, and to promote the cleaning, thereby ensuring operator maintenance. The present invention also provides an image reading apparatus that can be quickly performed.

In order to solve the above problems, an image reading apparatus according to claim 1 of the present invention comprises an original table glass for supporting an original,
Illumination means for illuminating the document;
A document conveying means for conveying the document by a predetermined control;
Optical means for illuminating the original moving on the platen glass by the original conveying means by the illuminating means, forming an image of the original reflected light on the photoelectric conversion element, and outputting an image signal;
Detecting means for detecting foreign matter on the platen glass;
Based on the result of the detection means, there is a display means for displaying a foreign matter adhesion position on the platen glass in an image reading apparatus having a correction means for correcting an image defect caused by the foreign matter on the platen glass,
A message operation panel that calculates a foreign matter adhesion position on the platen glass based on a detection result from the detection unit, indicates the foreign matter adhesion position on the platen glass to the operator, and prompts the operator to clean the position. It is characterized by being displayed.

The image reading apparatus according to claim 2 of the present invention for solving the above-mentioned problem is configured such that the display means includes a plurality of light emitting elements arranged in the main scanning direction and with a width equivalent to the platen glass. The plurality of light emitting elements can be individually controlled to be turned on, and the position of the deposit on the platen glass calculated based on the detection result from the detecting means is indicated by the lighting of the light emitting elements. It is a feature.

  An image reading apparatus according to claim 3 of the present invention for solving the above problems is characterized in that the display means is an operation panel.

  The object of the present invention is to eliminate image defects caused by foreign matter (dust such as paper dust) on the image. The position of the foreign matter is displayed in the vicinity of the glass so that the user can reliably remove the position of the foreign matter on the glass. A display means is provided.

  Specifically, among the light emitting elements arranged in a line in the main scanning direction, only the light emitting elements in the same position as the position of the foreign matter are turned on, and the user is informed of the position of the foreign matter on the glass intuitively. is there. As a result, the glass cleaning position can be clearly presented to the user, so that accurate and quick cleaning by the user can be expected.

  An image reading apparatus to which the present invention is applied will be described below with reference to the drawings.

  FIG. 1 is a view showing an image reading apparatus 100 according to the present invention.

  The flow reading operation of the image reading apparatus equipped with the document conveying device will be described with reference to FIG.

  The image reading apparatus 100 according to the present exemplary embodiment mainly includes a reading apparatus main body 101 and a document conveying apparatus 119.

  In the reading apparatus main body 101, reference numeral 102 denotes a lamp for illuminating a document, and 103 denotes a reflection shade. Reference numeral 104 denotes a lamp stay for holding the lamp 102 and the reflecting shade 103.

  Reference numeral 111 denotes a document glass (hereinafter referred to as a “flow-reading glass”) used for the flow-reading, and the reflected light of the document passes through the flow-reading glass 111 and the slit of the lamp stay and enters the first mirror 110. Reference numeral 111 denotes a second mirror, and 112 denotes a third mirror. Here, a component group including the lamp, the mirror, and the like is referred to as a mirror unit.

  The document reflected light incident on the first mirror 110 changes its optical path by the second mirror 111 and the third mirror 112 and is imaged on the light receiving surface of the line sensor 116 by the lens 113.

  Reference numeral 117 denotes a shading white plate serving as a white reference when calculating a shading coefficient.

  Reference numeral 118 denotes a glass (hereinafter referred to as a scan reading glass) on which an original is placed when reading a book mode. In the book mode, the document is fixed on the scanning reading glass, and the document is read by moving the mirror unit over the entire document area in the sub-scanning direction.

  Reference numeral 119 denotes a document conveying device.

  Reference numeral 120 denotes a document placing tray. Reference numeral 121 denotes a document placement sensor. When a document is set on the document placement tray 120, the document detection sensor detects that the document is in a stacked state. Here, the document conveyance is started by pressing a copy start button (not shown).

  The originals placed on the original placement tray 120 are picked up by the paper feed roller 122 in order from the topmost original, and are sequentially conveyed. The document passes through the transport path by the driving force of the transport roller 124 and is guided to the flow reading position 125 under the transport roller portion by the roller 123 (transport auxiliary roller).

  A registration sensor 127 detects the leading edge of the document being conveyed. Based on the timing of document detection by the registration sensor 127, the leading edge timing of the image in the document reading device is set.

  When the leading edge of the document reaches the flow reading position, the mirror unit is already waiting at the flow reading position and controls to read the document conveyed at a constant speed between the conveying roller 124 and the flow reading glass 111. Is done. The document that has been read is discharged to the paper discharge tray 126.

  FIG. 2 is a schematic diagram showing a lamp stay and its peripheral components of the document reading apparatus 101 of FIG.

  (A) is a top view surrounding a lamp stay, and (b) is a side view.

  Reference numeral 102 denotes a lamp. The lamp is supported at both ends by a lamp holder 105 and is fixed to the lamp stay 104 via the lamp holder 105. Reference numeral 106 denotes a slit provided to secure an optical path of the original reflected light. Similar to the lamp, the reflecting shade 103 is also fixed to the lamp stay.

  Reference numeral 107 denotes display means for indicating the position of dust (foreign matter) on the flow-reading glass that causes streak images. The dust position display means is composed of a plurality of LEDs, and is arranged in one row at predetermined intervals in the main scanning direction. The driving configuration is such that only predetermined LEDs can be turned on in accordance with a foreign object detection result on glass described later. Further, since the display means is attached to the lamp stay, it can be moved to an arbitrary position in the sub-scanning direction under the same control as the movement control of the mirror unit.

  FIG. 3 shows a control system of the entire apparatus. The same reference numerals as those in FIG. 1 denote the same components.

  A CPU 301 controls the entire image reading apparatus.

  Reference numeral 302 denotes an inverter that drives and drives the lamp 102 by a lighting signal from the CPU.

  Reference numeral 303 denotes an LED control circuit for the dust position display means 108, which turns on a specific LED on the display means under the control of the CPU 301. A motor driver 304 drives a scan motor 305 that reciprocally drives the mirror unit in the sub-scanning direction in accordance with a drive signal from the CPU 301.

  A timing signal generation unit 306 generates a driving signal for the CCD 114 and a timing signal for the image processing unit 307. The timing signal generator 306 controls the pulse width and clock phase of various timing signals and turns on / off the signal output under the control of the CPU.

  An image processing unit 307 includes an analog processing unit that samples a CCD signal, an AD conversion unit, a shading correction unit, a dust detection unit, and a streak image correction unit. The image signal processed by the image processing unit is sent to a subsequent device (not shown). The latter apparatus is, for example, a monochrome or color printer that prints the read image, and further performs image processing according to the printer output.

  A CPU 308 controls the entire document conveying device.

  Reference numeral 310 denotes a conveyance motor for driving a conveyance roller for conveying an original, and 312 denotes a paper feed motor for picking up an original placed on the original tray. The drive control of each motor is performed by the CPU 308 via the motor drivers 309 and 311.

  Reference numeral 121 denotes a document placement sensor, 126 denotes a registration sensor, and the CPU 308 monitors the registration sensor output and takes various control timings.

  The CPU 301 of the document reading apparatus and the CPU 308 of the document conveying apparatus are connected so as to communicate with each other, and perform various communications to control the document conveyance and the reading timing.

  FIG. 4 is a detailed view of the image processing unit 307 in FIG.

  A signal output from the CCD 114 is input to the analog processing unit 401. The analog processing unit samples and holds the CCD output signal, and processes such as gain correction and offset correction are performed on the result. The analog image signal subjected to the signal processing is converted into digital image data by the AD converter 402.

  The digital image data is sent to the shading correction unit 403.

  The shading correction is a process for correcting the sensitivity variation for each pixel of the CCD and the edge light amount deterioration of the CCD incident light. Before starting the image reading, the white plate 117 is read, a coefficient is calculated so that the read image data is uniformly a predetermined value, and the actual read image data and the correction data are calculated.

  Reference numeral 404 denotes a dust detection unit.

  When dust detection is instructed, image reading is started in order to detect dust on the flow reading glass 111. At this time, since the transport roller 124 is positioned on the upper part of the glass, the density of the transport roller 124 is read from the read data. Normally, the transport roller 124 is white, and the reading level when there is no dust on the glass is generally constant throughout the entire area.

  However, when there is dust on the reading position, the read data is data with a low luminance level because of light shielding by dust. The dust detection of this example uses this phenomenon to determine the presence or absence of dust from the difference in the reading brightness level of dust on the transport roller 124 and the flow-reading glass. To do.

  Reference numeral 405 denotes an addition average memory.

  In order to perform threshold determination, variations in the read image data cause erroneous determination. Therefore, the image data for performing threshold determination uses an addition average value to accurately detect dust.

  Reference numeral 406 denotes a threshold value setting unit, and 407 denotes a determination unit.

  When determining dust, the CPU sets a threshold value in the threshold setting unit.

  The threshold value and the addition average result are compared for each pixel, and image data that falls below the threshold value is determined as image data affected by dust. The output result of the determination unit 407 is an address of the addition average memory in which image data determined to be dust is stored, and the address is temporarily held in the dust pixel register 408.

  A streak image correction unit 409 determines a correction position from the dust pixel register 408 of the dust detection unit 404 and performs correction processing. The correction method includes replacement of image data with adjacent image data of dust pixels, but a detailed description of stripe correction is omitted here.

  The CPU 301 acquires dust position information from the dust pixel register 408, and starts lighting control of the LED of the dust position display means corresponding to the dust position on the glass.

  The CPU performs calculation for determining the LED to be lit from the dust position information in units of pixels acquired from the dust detection unit.

Assuming that the number of determination pixels in the dust detection unit is 7000 pixels and the number of LEDs mounted on the dust position display means 107 is 70 (the start address 0000 (d) of the determination pixel in the dust detection unit and the main scanning of the reading device) The setting is made so that the address corresponding to 700 (d) is assigned to one LED. In this example, the allocation is specifically as follows.
Dust detection pixel: 0000 (d) -00099 (d) -LED00
Dust detection pixel: 0100 (d) -0199 (d) -LED01
Dust detection pixel: 0200 (d) -0299 (d) -LED02
::
Dust detection pixels: 6300 (d) -6999 (d) -LED69
The CPU refers to the address of the dust position from the dust detection, and determines the LED to be turned on so that all the LEDs corresponding to the address are turned on.
The CPU secures 70 areas corresponding to the LED arrangement order in the built-in RAM and the like, sets a flag at a position corresponding to the LED to be lit, and completes the LED lighting information.

  Next, the circuit configuration of the dust position display means will be described with reference to FIG.

  500 is an external view showing an example of the dust position display means of the present invention.

  Reference numeral 501 denotes an LED mounted on the display means, and a plurality of LEDs are arranged in an array.

  Reference numeral 502 denotes a lighting control circuit for the LED 501. Reference numeral 503 represents the LED 501 in a circuit symbol. Reference numeral 504 denotes a resistor for controlling the current of the LED, and the light amount of the light emitting element is determined by a current value controlled by the resistor.

  Reference numeral 505 denotes a shift register, which is composed of a D-FF. The same number of registers as the LEDs of the display means 107 are prepared, and the ON / OFF control data of each LED supplied as serial data is sequentially transferred.

  The role of each input signal of the control signals 506, 408, 409, 410 is as follows.

Clear signal 506
This is a clear signal for the shift register 505, and sets the output terminal state of each shift register to a dephoto value. Holds shift register status at “H” level. All registers are cleared to “L” level at “L” level.

LED lighting signal 507
“H” and “L” berell signal data corresponding to the number of light emitting elements constituting the document illumination device, and the above-described LED lighting information is transferred.

Shift clock (data transfer clock) 508
The LED lighting signal 507 is sequentially transferred to the shift register 505 using a shift clock corresponding to the number of fermentation elements.

ON / OFF control signal 509
The lamp lighting control is performed at the “H” level, and the lamp lighting control is performed at the “L” level.

  The circuit operation controlled by the control signal is as follows.

  With the clear signal held from “L” level to “H” level, the above-described LED lighting signal 507 and shift clock 508 (data transfer clock) are input as the serial light emitting element selection signal 408, and each register LED lighting information is set to.

  An AND circuit 510 is connected to each register, and when the ON / OFF control signal 509 is turned on (“H”), the output of the AND circuit 510 corresponding to the control circuit unit of the selected LED is “H”. " The output of the AND circuit is supplied to a transistor 511 that functions as a light emitting element lighting control switch. Since the transistor is turned on, a light source element 503, a light amount control resistor 504, and a light emitting element are connected to the power source Vcc 513 connected to each element. A current flows through the GND 512 via the lighting control transistor 511 to light the LED.

  Next, a flow for realizing detection of dust on the glass and display of the dust position in flow reading will be described with reference to the flowchart of FIG.

  When the user sets a document on the document tray 120 of the document feeder, the document placement sensor 121 detects it (S601).

  In S602, a dust detection flag clear operation is performed.

  The dust detection flag is a flag indicating that dust is determined to be present as a result of dust detection and a cleaning message is displayed to the user. Clear this flag when the job starts.

  In the following, a flow when dust that causes streaks at the start of a job is attached to the reading glass will be described.

  Dust detection is started (S603).

  When dust detection starts, a shading coefficient is calculated. The mirror unit moves below the shading white plate 117 and turns on the lamp 102 to read an image. The read image data is subjected to predetermined processing by the image processing unit, and a shading correction unit calculates a shading coefficient.

  Subsequently, in order to perform image reading for dust detection, the mirror unit moves to the flow reading position 125 and starts reading. The read data is subjected to shading correction and then sent to a dust detection unit for dust determination.

  Based on the determination result in the dust detection unit, the presence or absence of dust on the glass is determined (S603). As a result of the dust determination, if it is determined that there is, the process proceeds to S605.

  In S605, the dust detection flag is confirmed.

  Since the flag is cleared in S602 after the job starts, the process proceeds to S606.

  Processing for presenting the dust position on the glass by the display means is started (S606). Specifically, the lighting location of the LED mounted on the display means is determined based on the detection result of the dust detection unit.

  In S <b> 607, based on the processing in S <b> 606, the LED of the display unit is actually turned on, and a message prompting the operation unit to clean the glass at the LED lighting location is displayed.

  In step S608, the dust detection flag is turned ON, and it is stored that a message prompting the user to clean is displayed.

  In step S609, it is determined whether the user has pressed the copy button.

  If the copy button has not been pressed, the process moves to S608, and it is determined whether the document feeder has been opened or closed.

  When cleaning the flow reading glass, it is necessary to open the document conveying device once. Therefore, if the opening / closing is detected, it can be determined that the user has cleaned the document. The actual determination process in S608 is the presence or absence of cleaning of the flow reading glass by the user. The opening / closing detection of the document conveying device is performed by an open / closed state detection switch (not shown) of the document conveying device.

  If it is determined in S608 that the opening / closing operation has been performed, it is determined that the user has cleaned the reading glass, and dust detection S603 is performed again. This is for confirming whether dust has been removed by cleaning.

  If it is determined again in step S604 that there is dust, the process proceeds to step S605, and dust detection flag determination is performed.

  Since the flag is turned on in S608, the flow moves to document reading S611.

  Here, since it is determined that there is dust in S604, it is possible to move to the flow after S606 again and urge the user to clean, but for example, it is not dust on the flow-reading glass and cannot be removed by cleaning such as scratches. For the reason, it may be determined that there is dust. In such a case, a cleaning message is displayed forever. Therefore, a flag for storing the display of the cleaning message is prepared, the cleaning message to the user is controlled once per job, and the streak image factor dust that cannot be removed by cleaning is the dust of the image processing unit. It is intended to eliminate the influence of dust lines by correction by the correction unit.

  In step S611, reading of a document is started. When this is completed, the flow proceeds to step S612.

  In S612, the presence / absence of the next original is determined.

  If there is no next original, the job ends. If there is a next original, dust detection for the next original is performed (S602).

  The dust detection in S602 is dust detection between sheets.

  As for the detection result of dust detection S602, the presence or absence of dust is determined in S603. If it is determined that there is no dust, the process advances to S611 to start reading the next original.

  If it is determined that there is dust, a dust detection flag is determined in S605.

  If the flag is ON, it is determined that the user has already given a cleaning instruction, and the process proceeds to the original reading flow in S611, where the next original is continuously read. When there is dust, control is performed to change the correction location of the dust correction unit with reference to the dust detection result.

  If it is determined that there is no dust in the dust detection S603 at the start of the job, the process proceeds to S604 and waits for the user to press the copy button.

  Triggered by the copy button being pressed, the process proceeds to S611 to start reading the first document.

  When the reading is completed, the control is performed according to the flow after S612 described above.

  If it is determined that there is dust in the inter-paper dust detection S602, the flow proceeds to S606 in flag determination S605, and the flow is made to prompt the user to clean the reading glass.

  FIG. 7 schematically shows an example of means for displaying the dust position.

  7A shows dust position display means when the reading device is viewed from above, and FIG. 7B shows dust position display means when the reading device is viewed from the side of the reading device.

  When the dust detection unit determines that there is dust and instructs the user to indicate the dust position on the flow reading glass, the display means first moves by the scan motor so that the center of the LED array is at the flow reading position. Be made. After completion of the movement to the flow reading position, the LED corresponding to the dust position is turned on.

  As shown in FIG. 7, since the LED is turned on just below the dust 701 on the flow reading glass, it is possible to accurately notify the user of the dust position. Therefore, it is possible to perform maintenance by the user reliably and quickly, and it is possible to eliminate streak images caused by dust.

  In this embodiment, a method of displaying dust positions that cause streak images in a so-called roller flow reading by using a document conveyance device that conveys a document by a conveyance roller and a document reading device having a flow reading glass has been described. It is also possible to implement a device for performing the continuous reading without changing the configuration and control described above.

  Moreover, although LED was used for the display means of a dust position, it should just be what can clearly show the dust position on glass, and is not limited to LED.

1 is an image reading apparatus according to the present invention. It is a schematic diagram of a lamp stay and its peripheral components. It is a control system diagram of the whole apparatus. FIG. 4 is a detailed view of an image processing unit 307 in FIG. 3. It is the external view which showed an example of the dust position display means. It is a flowchart for implement | achieving the detection of the dust on the glass in a flow reading, and the display of a dust position. It is a schematic diagram of the dust position instruction | indication by a display means.

Explanation of symbols

101 Reading Device Body 102 Lamp 103 Reflecting Shade 104 Lamp Stay 105 Lamp Holder 107 Dust Position Display Means 108 LED
111 Flow Reading Glass 117 Shading White Plate 118 Scan Reading Glass 125 Flow Reading Position 120 Document Tray 121 Document Placement Sensor 122 Paper Feed Roller 124 Transport Roller 127 Registration Sensors 301, 308 CPU
302 Inverter 303 LED drive circuit 305 Scan motor 306 Timing generation circuit 307 Image processing unit 401 Analog processing unit 402 AD conversion unit 403 Shading correction unit 405 Addition averaging unit 406 Determination threshold value register 407 Dust determination unit 408 Dust pixel register 409 Line correction 502 LED drive circuit 505 shift register

Claims (3)

A platen glass for supporting the document;
Illumination means for illuminating the document;
A document conveying means for conveying the document by a predetermined control;
Optical means for illuminating the original moving on the platen glass by the original conveying means by the illuminating means, forming an image of the original reflected light on the photoelectric conversion element, and outputting an image signal;
Detecting means for detecting foreign matter on the platen glass;
Based on the result of the detection means, there is a display means for displaying a foreign matter adhesion position on the platen glass in an image reading apparatus having a correction means for correcting an image defect caused by the foreign matter on the platen glass,
A message operation panel that calculates a foreign matter adhesion position on the platen glass based on a detection result from the detection unit, indicates the foreign matter adhesion position on the platen glass to the operator, and prompts the operator to clean the position. An image reading apparatus characterized by being displayed on the screen.   The display means is composed of a plurality of light emitting elements arranged in a row with a width equivalent to the original table glass in the main scanning direction, and the plurality of light emitting elements can be individually controlled to be lighted, and the detecting means 2. The image reading apparatus according to claim 1, wherein the position of the foreign matter detected on the platen glass is indicated by lighting of the light emitting element.   2. The image reading apparatus according to claim 1, wherein the display means is an operation panel.

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