JP2006140577A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reading apparatus for preventing the occurrence of image deterioration due to dispersion in the carrying, of a striped image due to application of a correction fluid not properly dried, and of dropping of a foreign material such as a needle of a stapler or a clip into the image reading apparatus. <P>SOLUTION: A shutter is provided between a draft feeder the sheet guide of which has a sit and an image read unit, part of the shutter is formed with a transparent member, and the shutter is configured to be moved in interlocking with the movement of the image read unit, and the image reading apparatus is characterized in that when the image read unit moves to a skim-through unit, the transparent part of the shutter moves to the skim-through unit, and when the image read unit moves to an escape unit, the components other than the transparent part of the shutter move to the skim-through unit. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus that reads an image of a sheet material (original) on which an image is placed, such as a scanner, a copying machine, a printer, or a facsimile machine.

  2. Description of the Related Art Conventionally, in an image reading apparatus provided in a digital copying machine, a printer, a facsimile, or the like, a document processing apparatus (ADF: Auto), which is an example of an automatic sheet conveying apparatus, is used to automatically feed a document as a sheet to the image reading apparatus. Some have a Document Feeder) that can be freely opened and closed.

  As one of the reading methods of the image reading apparatus provided with the document processing apparatus, a reading apparatus provided below the document processing apparatus is moved to a set position by a motor for a document automatically fed by the document processing apparatus. There is a method of reading an image by emitting light from a lamp unit to scan a document conveyed at a predetermined speed after scanning, and detecting the reflected light by a reading device (hereinafter referred to as flow reading). Called).

  In this conventional scanning reading technique, there is a technique in which means for conveying a document without contacting it at a predetermined reading position on the flow reading glass is provided. As an example, there is a method in which a step is provided in a flow reading glass to convey a document by floating (for example, refer to Patent Document 1), and a method in which reading is performed by forming slits at a minute interval on a document table glass (for example, , See Patent Document 2).

  Hereinafter, referring to FIGS. 6 and 7, a description will be given of a conventional means for conveying an original without bringing it into contact with a predetermined reading position on a flow reading glass.

  First, FIG. 6 will be described with reference to Patent Document 1. FIG. In the document reading apparatus shown in FIG. 6, a step forming member 2a is provided on the reading glass 1, and a flat plate 3 is provided so as to face and separate from the reading glass 1 and the step forming member 2a. It is a configuration. In the drawing, P indicates a document sheet, and R indicates a reflection direction of reflected light from the document sheet, that is, a reading position.

  Further, the flat plate may be any plate that is disposed to face the reading glass and can reflect the irradiation light transmitted through the original paper. For example, a white roller arranged to face the reading glass. But it ’s okay.

  Next, FIG. 7 will be described with reference to Patent Document 2. FIG. FIG. 7 is an explanatory view showing, in an enlarged manner, the reading portions of the backup roller 114 and the document table 111 according to the conventional example. As shown in the figure, a slit hole 111a having a width of 1 to 3 mm in the main scanning direction is formed in the narrowest portion formed by the backup roller 114 and the document table 111, that is, the portion serving as a reading position.

  Further, the upper corner on the downstream side of the slit hole 111a is chamfered (C surface) in order to improve the transportability of the document 101. That is, even if a part of the front end of the document 101 is slightly lowered and conveyed, it is scooped up.

  Furthermore, the surfaces A, B, and C in FIG. 7 are polished to be transparent. Thereby, the illumination light of the lamp 113 is transmitted and a sufficient amount of light can be supplied to the reading portion.

As described above with reference to Patent Documents 1 and 2, in order to transmit the illumination light and the reflected light of the document, the reading unit is formed of a reading glass or a slit.
Japanese Patent Laid-Open No. 9-307695 (page 7, FIG. 3) Japanese Patent Laid-Open No. 9-093405 (page 7, FIG. 1)

  However, the conventional image reading apparatus having a means for conveying an original without contacting it at a predetermined reading position on a flow reading glass has the following drawbacks.

  First, as shown in Patent Document 1, the method of providing a step forming member on the glass cannot completely prevent the fluttering of the original at the reading position, so that it is particularly like an image reading apparatus using a color CCD. In an apparatus that requires reading accuracy, there is a concern about image deterioration due to variations in conveyance.

  In addition, since the gap between the reading glass and the original cannot be set large, if a large amount of semi-drying correction liquid or ballpoint pen ink adheres to the original, the reading glass will come into contact with the reading glass surface, causing streaking. It will be read as an image.

  Also, as shown in Patent Document 2, in the method of forming a slit hole in the glass, since the reading device always has a hole, if the user mistakenly conveys the document with a staple or a clip, There is a concern that foreign matters such as staples and clips may fall into the reading device.

  In addition, transportability for specially shaped paper such as folded paper and curled paper is also reduced, and if it gets caught in the slit, the document enters the reader and it is very difficult for the user to remove the document. .

  The present invention has been made paying attention to the above points. Image degradation due to variations in conveyance, generation of streaks due to semi-drying correction liquid and ballpoint pen ink, stapling needles and clips in the reading device. An object of the present invention is to provide an image reading apparatus that prevents the fall of foreign matters such as the above.

  The present invention adopts the following configuration in order to solve the above problems.

  A conveyance roller that conveys the sheet to a predetermined reading position; a first guide member that guides the sheet to the predetermined reading position; and a second guide member that guides the sheet that has passed the predetermined reading position; A document conveying device provided with a first guide member and a second guide member so as to form a slit having a predetermined width in the main scanning direction on a predetermined reading position, and an image of a sheet conveyed to the predetermined position In an image reading apparatus having a sink reading unit for reading during conveyance and an image reading unit movable between the sink reading unit and the retracting unit, a shutter is provided between the reading unit and the document conveying device, and a part of the shutter is a transparent member The shutter is moved in conjunction with the movement of the image reading unit. During movement, flow moves transparent portion of the shutter is in the reading unit, at the time of moving to the retracted portion of the image reading unit, wherein the non-transparent portion of the flow shutter to the reading unit is moved configuration.

  An image reading calibration unit that performs shading correction using a white reference plate and a fixed reading unit that reads an image of a document fixed on the platen glass by moving the image reading unit are provided in the retracting unit, and the calibration unit of the image reading unit The transparent portion of the shutter is also moved to the proofreading unit as it is moved to.

  When the image reading unit is moved to the sink reading unit, the biasing unit biases the shutter in the direction of the platen glass, a projection provided on the shutter, and a claw provided on the reading unit. The projection and the claw are engaged, and the shutter is moved by pushing the shutter in the direction opposite to the platen glass, the transparent part of the shutter is moved to the sink reading part, and the image reading unit is moved to the retracting part. When the projection part and the claw part are separated, the shutter is pushed toward the platen glass by the urging member, and the part other than the transparent part of the shutter moves to the sink reading part.

  In addition, the cleaning tool is provided between the sink reading unit and the fixed reading unit, and the cleaning tool is arranged so that the transparent member can be cleaned as the shutter moves.

  In addition, a configuration is characterized in that magnetic flux generating means is provided at the end of the sink reading section, and magnetic body recovery means for recovering the magnetic body as the shutter moves is arranged.

  According to the present invention, since it is possible to avoid the original from coming into direct contact with the reading glass, the reading glass is prevented from being stained by adhering dust such as a semi-drying correction liquid or a large amount of ball-point pen ink on the original. There is an effect of improving the frequency of occurrence of image defects that are read.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.

(Explanation of the device)
1 and 2, reference numeral 2 denotes a document processing apparatus, 150 denotes a reader unit which is a reading apparatus, and 300 denotes an image forming apparatus.

(Description of image forming apparatus)
First, the configuration and operation of the image forming apparatus will be described with reference to FIG. As shown in FIG. 1, in the image forming apparatus, when an image reading start signal is input, a photosensitive drum 351 as an image carrier is charged by a charging unit 353 so as to have a predetermined potential. On the other hand, in the document processing apparatus 2 that reads a document while conveying it, the image of the document is read and an image signal is sent to the image forming unit 300 for image formation.

  In the image forming unit 300, an electrostatic latent image corresponding to the original image is formed on the photosensitive drum 351 by an exposure unit 352 such as an LED or a laser that receives the image signal and emits light ON and OFF. Next, the electrostatic latent image is developed by a developing unit 354 as a developing unit containing toner particles, and a toner image is obtained on the photosensitive drum 351.

  In this way, the toner image formed on the photosensitive drum 351 is electrostatically transferred onto a recording medium such as paper or an OHP sheet by the transfer device 357. Thereafter, the recording medium is electrostatically separated and conveyed to a fixing device 356, where it is thermally fixed and an image is output.

  On the other hand, the surface of the photosensitive drum 351 after the transfer of the toner image is exposed by a pre-exposure unit 358 that removes adhering contaminants such as transfer residual toner by a cleaner 355 and, if necessary, an optical memory (ghost) of image exposure. It is repeatedly used for image formation.

(Description of document processing device)
In FIG. 1, the automatic document feeder 2 is provided above the reader unit 150 so as to be openable and closable with respect to the document table glass 3 via hinge mechanisms 95 and 96 (not shown). Hereinafter, details of the document processing apparatus 2 will be described with reference to the drawings.

  In FIG. 2, a document tray 4 is for stacking sheet-shaped documents P. A pair of width direction restricting plates are arranged on the document tray 4 so as to be slidable in the document width direction. By regulating the width direction of the documents P stacked on the document tray 4 by the width direction regulating plate, it is possible to ensure the conveyance stability during feeding.

  A paper feed roller 5 is provided above the document tray 4. The sheet feeding roller 5 rotates as the separation conveying roller 8 rotates and feeds a sheet document.

  The paper feed roller 5 normally takes a position retracted above the home position (solid line position in the figure) so as not to disturb the document setting operation. When the sheet feeding operation is started, the sheet descends to the dotted line position in the figure and comes into contact with the upper surface of the document P. Since the sheet feeding roller 5 is pivotally supported by an arm (not shown), the arm can be swung to move the sheet feeding roller 5 up and down.

  The separation pad 6 is disposed on the side opposite to the separation conveyance roller 8 and applies pressure to the separation conveyance roller 8 side. The separation pad 6 is formed of a rubber material or the like whose friction is slightly smaller than that of the separation transport roller 8. The separation pad 6 separates the originals P fed by the paper feed roller 5 one by one and feeds the paper by the separation transport roller 8.

  The registration roller 12 and the registration driven roller 11 are registration means for aligning the leading edges of the documents fed by the separation unit, and abutting the separated document fronts toward the nip portions of the stationary registration roller pairs 11 and 12, The loops are made to align the tips.

  Next, the document P is transported along the upstream transport guide 25 by the lead roller 22 and the lead driven roller 14. At this time, a slit having a predetermined width is formed by the upstream conveyance guide 25 and the downstream conveyance guide 26. The first optical stand 159 is fixed at the position of the slit, and the image of the original P is read. The document that has passed through the slit is picked up by the downstream conveyance guide 26 and conveyed by the lead discharge roller 23 and the lead discharge driven roller 16.

  When the image reading is completed, the document is discharged onto the discharge tray 10 by the discharge roller 18.

  In the duplex mode, the paper is not discharged by the paper discharge roller 18 but is switched back, guided to the upper paper path, and conveyed toward the registration rollers 11 and 12. When the registration rollers 11 and 12 are reached, the back side of the document is read in the same manner as described above.

(Image reading device)
In FIG. 2, the reader 150 includes a lamp 152 that irradiates light on the original surface, and mirrors 153 and 155 that guide reflected light from the original P corresponding to the light emitted from the lamp 152 to the lens 157 and the CCD 158. 156. The lamp 152 and the mirror 153 are attached to the first optical bench 159, and the mirrors 155 and 156 are attached to the second optical bench 151.

  The optical benches 159 and 151 are coupled to a motor 171 (not shown) by a wire 154 (not shown), and are controlled to move in parallel with the document table glass 3 by the rotation of the motor 171.

  The position sensor 173 is a sensor for detecting the home position of the first optical bench 159, and moves the optical benches 159 and 151 by rotating the motor 171 forward and backward based on the position of the position sensor 173. The document on the platen glass 3 is optically scanned. In addition, a white reference plate 154 is disposed at the same position as the document surface height at the home position so that shading correction can be performed. Further, a shutter 161 is disposed at the sink reading position, and slides in conjunction with the movement of the optical bench.

  The motor 171 is a stepping motor. An encoder 175 (see FIG. 3) is connected to the motor 171, and the number of pulses that the optical benches 159 and 151 have moved can be recognized by the output of the encoder 175. That is, the positions of the optical benches 159 and 151 can be grasped by encoder pulses from the position sensor 173 and the encoder 175.

  Reflected light from the original is guided to the lens 157 via the mirrors 153, 155 and 156, and is condensed on the CCD 158 by the lens 157. The CCD 158 photoelectrically converts the reflected light reflecting the document information and outputs it as an electronic image signal.

  Under such a configuration, with the first optical table 159 stopped at the reading position 160, the document processing apparatus 2 feeds the document information while scanning the document information, and the document is fixed on the document table glass 3. Thus, the document information can be read in two modes: a reading method for reading the document information while moving the optical benches 159 and 151 in the sub-scanning direction (hereinafter referred to as fixed reading).

(Description of control system)
FIG. 3 is a block diagram illustrating a schematic configuration of a control system of the image reading apparatus.

  A lamp 152 for irradiating light on the original surface, a motor 171 for scanning the original by moving the optical benches 159 and 151 in the sub-scanning method, and an output signal of the CCD 158 and CCD 158 for photoelectrically converting reflected light from the original surface are A / D converted. A / D conversion circuit 174, encoder 175 connected to motor 171; lamp 152 for irradiating light on the original; position sensor 173 for positioning optical bench 159 at the home position; regular in ADF original reading mode A backup RAM 172 for setting the document reading position and a scanner controller 176 are provided.

(Explanation of shutter configuration)
Next, the shutter configuration will be described with reference to FIG.

  Reference numeral 161 denotes a shutter, which includes a non-transparent portion a, a transparent portion b, and a projection portion c. In this, a non-transparent portion and a protruding portion made of black ABS material and a transparent portion made of transparent ABS material are formed into an integral mold shutter by a two-color molding method.

  The shutter 161 is supported by a shutter guide 162 so as to be slidable, and is pressed in the horizontal direction by the shutter spring 163.

  Thereby, when the optical bench 159 is moved to the sink reading position, the projection c of the shutter 161 is engaged with the claw d of the optical bench 159, and the slide is restricted. In this state, the transparent portion b of the shutter 161 slides at the reading position.

  Further, when the optical bench 159 moves to the home position, the projection c of the shutter 161 is engaged with the shutter regulating member 166 and the sliding is regulated. In this state, the dimensions are such that the non-transparent portion a of the shutter 161 slides at the reading position.

  In addition, a cleaning tool 164 is disposed in the reader unit housing on the right side of the reading position so as to contact the surface of the shutter 161. The cleaning tool 164 is formed by attaching a nonwoven fabric to the surface of the elastic seal, and is configured to lightly contact the surface of the shutter 161 by the elastic force of the elastic seal and to perform cleaning by moving the shutter.

  Further, a magnetic body recovery means 165 is arranged on the reader unit housing on the left of the reading position so as to be close to the surface of the shutter 161. Magnet rubber is used for the magnetic body collecting means 165, and the magnet rubber is pasted up to the maximum image area in the main scanning direction.

(Explanation of shutter mechanism operation)
Next, the operation of the shutter mechanism will be described in detail with reference to FIG.

  Step (1) indicates a standby state of the image reading apparatus, and the optical bench 159 is waiting at the home position. In this case, the non-transparent portion a of the shutter 161 has been moved to the reading position, and the reading portion is shielded from light and foreign matter is shielded. Further, the transparent portion b of the shutter 161 is moved to the shading portion, and the spectral characteristics of the transparent member are also subjected to shading correction.

  Step (2) shows the moving state of the image reading apparatus to the sink reading position, and the optical bench 159 has moved to the sink reading position. In this case, the transparent portion b of the shutter 161 moves to the reading position while being cleaned by the cleaning tool 164. Further, the non-transparent portion a of the shutter 161 moves while collecting the magnetic foreign matter in the magnetic body collecting means 165.

  Step (3) shows the state of starting the reading of the image reading apparatus, and the optical bench 159 starts the reading at the reading position. In this case, when the document processing apparatus conveys the document to the reading position and the lead sensor 13 detects the leading edge of the document, image reading is started.

  Step (4) shows a sink reading standby state of the image reading apparatus, and the optical bench 159 stands by at the sink reading position. In this case, the document is conveyed from the reading position by the document processing apparatus, the leading edge of the document is detected by the lead sensor 13, and the image reading is finished after an arbitrary time corresponding to the document size has elapsed.

  Step (5) shows a state where the image reading apparatus has finished reading, and the optical bench 159 has moved from the reading position to the home position. In this case, the dust floating on the transparent portion b of the shutter 161 is moved to the shading portion while being cleaned by the cleaning tool 164. In addition, the magnetic foreign matter collected by the magnetic body collecting means 165 moves to the reading position of the non-transparent portion a of the shutter 161 while being held by the magnetic force, and the transparent portion b of the shutter 161 moves to the shading portion.

  Thereafter, the state (1) is entered and the series of operations ends.

1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment. 1 is a diagram illustrating a configuration of an image reading apparatus according to the present embodiment. Control block diagram of image reading apparatus according to this embodiment The figure explaining the shutter composition concerning this embodiment The figure explaining operation | movement of the shutter mechanism which concerns on this embodiment. The figure of patent document 1 explaining the image reading apparatus based on a prior art The figure of patent document 2 explaining the image reading apparatus based on a prior art

Explanation of symbols

2 Automatic document feeder (original processing device)
DESCRIPTION OF SYMBOLS 3 Document glass 4 Document tray 5 Feed roller 6 Separation pad 8 Separation conveyance roller 11 Registration driven roller 12 Registration roller 14 Lead driven roller 16 Lead discharge driven roller 22 Lead roller 23 Lead discharge roller 150 Leader unit 151 Optical table 159 Optical table 161 Shutter 162 Shutter guide 163 Shutter spring 164 Cleaning tool 165 Magnetic body recovery means 166 Shutter restricting member

Claims (5)

A conveyance roller that conveys the sheet to a predetermined reading position; a first guide member that guides the sheet to the predetermined reading position; and a second guide member that guides the sheet that has passed the predetermined reading position; A document conveying device in which a first guide member and a second guide member are provided so as to form a slit having a predetermined width in the main scanning direction on a predetermined reading position;
In an image reading apparatus having a flow reading unit that reads an image of a sheet conveyed to a predetermined position during conveyance, and an image reading unit that is movable between the flow reading unit and the retracting unit,
A shutter is provided between the reading unit and the document conveying device, and at least a part of the shutter is formed of a transparent member, and the shutter moves in conjunction with the movement of the image reading unit. An image reading apparatus in which the transparent portion of the shutter is moved to the sink reading portion when moving, and the transparent portion other than the transparent portion of the shutter is moved to the sink reading portion when moving to the retracting portion of the image reading unit.   An image reading calibration unit that performs shading correction using a white reference plate and a fixed reading unit that reads an image of a document fixed on a platen glass by moving the image reading unit are provided in the retracting unit, and the image reading unit is calibrated. The image reading apparatus according to claim 1, wherein the transparent portion of the shutter is also moved to the calibrating portion in accordance with the movement to the portion.   Consists of an urging means for urging the shutter in the direction of the platen glass, a projection provided on the shutter, and a claw provided on the reading unit. When the image reading unit moves to the sink reading unit, the projection When the shutter and the claw are engaged, the shutter moves by pushing the shutter in the opposite direction to the platen glass, the transparent part of the shutter moves to the sink reading unit, and the image reading unit moves to the retracting unit. 2. The image reading apparatus according to claim 1, wherein the projection and the claw are separated from each other, and the shutter is pushed toward the platen glass by the urging member, and other than the transparent portion of the shutter moves to the sink reading unit.   The image reading apparatus according to claim 1, wherein a cleaning tool is provided between the sink reading unit and the fixed reading unit, and the cleaning tool is disposed so that the transparent member can be cleaned as the shutter moves.   2. The image reading apparatus according to claim 1, wherein a magnetic flux generating means is provided at an end of the sink reading section, and a magnetic material collecting means for collecting the magnetic material as the shutter moves is disposed.

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