JP2010273279A - Image reader and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader in which a document is appropriately irradiated with light and non-uniformity in a document read density is reduced. <P>SOLUTION: An image reader includes: a document conveyance part 70 for conveying a document G to a document read position R; first document state detectors 440, 450 for detecting the state of the document G to be conveyed to the document read position R by the document conveyance part 70; a light emitting part 500 configured to change the quantity of light to be emitted by a plurality of light-emitting members 501 for emitting light H0 with which the document G located at the document read position R is irradiated; a light emission quantity control part 411 for controlling the quantity of light to be emitted by the plurality of light-emitting members 501 on the basis of the state of the document G detected by the first document state detection parts 440, 450; mirrors 321, 322 for forming an optical path H by reflecting light flux H from the document G; an imaging lens for imaging the light flux H reflected by the mirrors 321, 322; and an image sensor which is disposed at the imaging position of the imaging lens and reads the image of the document G on the basis of imaging by the imaging lens. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image reading apparatus and an image forming apparatus including the image reading apparatus.

  2. Description of the Related Art Conventionally, as an image reading apparatus that reads an image of a document, a document transport unit that transports the document to a predetermined document reading position, a light emitting unit that emits light to irradiate the document located at the document reading position, and a document reading position A contact glass (platen glass) that transmits light emitted from the light emitting unit, a mirror that reflects light from the document to form an optical path, an imaging lens that forms an image of a light beam from the document, and an imaging lens There is known an image reading apparatus including a CCD (Charge-Coupled Device) that reads an image of an original image formed by the above (see, for example, Patent Document 1 below).

  The image reading apparatus described in Patent Literature 1 includes a platen roller provided above the platen glass, and a gap amount adjusting unit that adjusts a gap amount between the platen glass and the platen roller. According to the image reading apparatus described in Patent Literature 1, the gap amount between the platen glass and the platen roller is adjusted by the gap amount adjusting unit, thereby preventing the document from being shaken or lifted at the document reading position, thereby reading a clear image. It is supposed to be possible.

JP 2003-207856 A

In recent years, a light emitting unit configured by arranging a plurality of LEDs (light emitting members) at a predetermined interval in the main scanning direction is often used as the light emitting unit.
The technique described in Patent Document 1 does not consider variations in the gap amount in the main scanning direction, and cannot change the gap amount between the platen glass and the platen roller in the main scanning direction. For this reason, the technique described in Patent Document 1 is not effective for a document reading position including a light emitting unit configured by arranging a plurality of LEDs at predetermined intervals in the main scanning direction.

The present invention provides an image reading apparatus including a light emitting unit configured by arranging a plurality of light emitting members that emit light to irradiate a document located at a document reading position at a predetermined interval in the main scanning direction. An object of the present invention is to provide an image reading apparatus that can appropriately irradiate and can reduce unevenness in reading density of a document.
Another object of the present invention is to provide an image forming apparatus including the image reading apparatus.

  The present invention includes a document transport unit that transports a document to a predetermined document reading position, a first document state detection unit that detects a state of the document transported to the document reading position by the document transport unit, and the document reading A plurality of light emitting members that emit light to irradiate the document located at a predetermined interval in the main scanning direction, and a light emitting unit configured to change a light emission amount of each of the plurality of light emitting members; Based on the document state detected by the first document state detection unit, a light emission amount control unit for controlling the light emission amounts of the plurality of light emitting members, and an optical path is formed by reflecting a light beam from the document. Or a plurality of mirrors, an image forming lens for forming an image of the light beam reflected by the one or more mirrors, and an image forming position of the image forming lens, and the original based on the image formed by the image forming lens of An image sensor for reading an image, an image reading apparatus comprising a.

  Preferably, the document conveying unit includes a transparency sensor that detects the transparency of the document conveyed to the document reading position, and the first document state detecting unit includes the transparency sensor.

  Further, it is preferable that the document transport unit includes a gloss sensor that detects a gloss level of a document transported to the document reading position, and the first document state detection unit includes the gloss sensor.

  A document state setting unit configured to set a state of the document before the document conveyance unit starts conveying the document; and the light emission amount control unit is configured to control the document set by the document state setting unit. It is preferable to control the light emission amounts of the plurality of light emitting members based on the state.

  A second document state detection unit configured to detect a state of the document located at the document reading position, and the light emission amount control unit is configured to detect a state of the document detected by the second document state detection unit; It is preferable to control light emission amounts of the plurality of light emitting members.

  Further, the image sensor is a plurality of lines of line-type image sensors arranged corresponding to the document transport direction, and the second document state detection unit is configured to detect the document transport direction of the plurality of lines of line-type image sensors. The first line type image sensor that receives light first is preferable.

  Further, it is preferable that the state of the original is detected based on a region in the vicinity of the upstream end in the transport direction and / or a region in the vicinity of the downstream end of the original.

  Further, it is preferable that the state of the original includes the dimensions of the original.

  The present invention also provides the image reading device, an image carrier on which an electrostatic latent image is formed based on image information relating to the image of the original read by the image reading device, and the image carrier. A developing unit that develops a toner image on the electrostatic latent image formed on the image carrier, a transfer unit that directly or indirectly transfers the toner image formed on the image carrier onto a predetermined sheet, and the transfer unit The present invention relates to an image forming apparatus including a fixing unit that fixes a toner image transferred to a predetermined sheet.

According to the present invention, in an image reading apparatus including a light emitting unit configured by arranging a plurality of light emitting members that emit light to be applied to a document located at a document reading position at a predetermined interval in the main scanning direction, It is possible to provide an image reading apparatus capable of appropriately irradiating light and reducing unevenness in reading density of a document.
In addition, according to the present invention, an image forming apparatus including the image reading apparatus can be provided.

2 is a diagram for explaining the arrangement of each component of the copier 1. FIG. 3 is a plan view illustrating an outline of an internal structure of a reading unit 301 of the image reading apparatus 300. FIG. FIG. 3 is a diagram of a reading unit 301 of the image reading apparatus 300 viewed from the main scanning direction Y. It is a figure which shows the outline | summary of the moving mechanism 370 of the illumination unit 347 and the mirror unit 349. FIG. 3 is a diagram schematically showing a structure around a document reading position R of the image reading apparatus 300. FIG. It is a perspective view which shows the illumination part 340 which consists of LED unit 500. FIG. FIG. 3 is a functional block diagram illustrating functions of the image reading apparatus 300 according to the first embodiment. 6 is a diagram illustrating an example of a relationship among a state of a sheet T at a document reading position R, a reading density, a light amount, and an arrangement of an LED 501. FIG. 6 is a diagram illustrating another example of the relationship between the state of the paper T at the original reading position R, the reading density, the light amount, and the arrangement of the LEDs 501. FIG. 3 is a flowchart illustrating an operation of the image reading apparatus 300 according to the first embodiment. It is a functional block diagram which shows the function of the image reading apparatus 300 of 2nd Embodiment. It is a perspective view which shows CCD358 in 2nd Embodiment. (A) is a figure which shows the relationship between the optical path H and CCD358 in 2nd Embodiment, (B) is the elements on larger scale of (A). 10 is a flowchart illustrating an operation of the image reading apparatus 300 according to the second embodiment.

Hereinafter, embodiments of an image forming apparatus of the present invention will be described with reference to the drawings.
With reference to FIG. 1, the overall structure of a copying machine 1 as an image forming apparatus of the present invention will be described. FIG. 1 is a diagram for explaining the arrangement of each component of the copier 1.

As shown in FIG. 1, a copier 1 as an image forming apparatus is disposed on an upper side in the vertical direction Z of the copier 1 and on a lower side of the copier 1 in the vertical direction Z. An apparatus main body M that forms a toner image on a sheet T as a sheet-like transfer material based on image information read by the image reading apparatus 300.
In the description of the copying machine 1, the sub-scanning direction X is also referred to as the “left-right direction” of the copying machine 1, and the main scanning direction Y (direction passing through FIG. 1, see FIG. 2) is also referred to as the “front-rear direction” of the copying machine 1. Say. The vertical direction Z of the copier 1 is orthogonal to the sub-scanning direction X and the main scanning direction Y.

First, the image reading apparatus 300 according to the first embodiment will be described.
As shown in FIG. 1, the image reading apparatus 300 includes a reading unit 301 that reads an image of a document G, and a document conveying unit 70 that is arranged above the reading unit 301 and conveys the document G to the reading unit 301. .

  The reading unit 301 includes a housing 306, and a first reading surface 302 </ b> A and a second reading surface 302 </ b> B disposed on the upper side of the housing 306. The reading unit 301 includes an illumination unit 340 including a light source, a plurality of mirrors 321, 322, and 323, and a first frame 311 and a second frame that move in the sub-scanning direction X in an internal space 304 of the housing 306. A body 312, an imaging lens 357, a CCD 358 as an image sensor, and a CCD substrate 361 that performs predetermined processing on image information read by the CCD 358 and outputs the image information to the apparatus body M side. Prepare. The illumination unit 340 and the first mirror 321 are accommodated in the first frame 311. The second mirror 322 and the third mirror 323 are accommodated in the second frame 312.

  The document conveying unit 70 is connected to the reading unit 301 so as to be openable and closable by a connecting unit (not shown). The document conveying unit 70 has a document placing unit 71 on the upper side, and a feed roller (not shown) inside. The document conveying unit 70 has a function of protecting the first reading surface 302A and the second reading surface 302B of the reading unit 301.

  The first reading surface 302 </ b> A is a reading surface used when reading the document G conveyed by the document conveying unit 70. First reading surface 302A is formed along the upper surface of first contact glass 335A on which document G is conveyed. The first reading surface 302A is located near the left side surface of the housing 306. Note that this position shown in FIG. 1 is also referred to as a “first reading position”.

The second reading surface 302 </ b> B is a reading surface used when reading the document G without using the document transport unit 70. The second reading surface 302B is formed along the upper surface of the second contact glass 335B on which the document G is placed. The second reading surface 302B is on the right side of the first reading surface 302A and extends over most of the sub-scanning direction X in the reading unit 301.
The first reading surface 302A and the second reading surface 302B extend in a direction orthogonal to the sub-scanning direction X and the main scanning direction Y.

  When reading the document G conveyed by the document conveyance unit 70, the document G is placed on the document placement unit 71. The document G placed on the document placement unit 71 is conveyed to the first reading surface 302 </ b> A of the reading unit 301 by the feed roller provided inside the document conveying unit 70. In this case, the first frame body 311 and the second frame body 312 are arranged at the first reading position and do not move. Then, the original G is conveyed by the original conveying unit 70 so as to slide on the first reading surface 302A, and an image formed on the surface of the original G is read by the CCD 358 serving as a reading unit.

  Further, when the document conveying unit 70 is in an open state, the document G is placed on the second reading surface 302B. In this case, each of the first frame body 311 and the second frame body 312 moves in the sub-scanning direction X while keeping the length of an optical path H (optical path length) to be described later constant. Thereby, the image of the original G placed on the second reading surface 302B is read.

  In the internal space 304 of the housing 306, the plurality of mirrors 321, 322, and 323 form an optical path H for allowing light from the original G to enter the imaging lens 357. In addition, the first frame 311 moves at a constant speed A in the sub-scanning direction X, and the second frame 312 moves at a constant speed A / 2 in the sub-scanning direction X. The length of H is kept constant. Details of the reading unit 301 will be described later.

Next, the apparatus main body M will be described.
The apparatus main body M is configured to form a predetermined toner image on the paper T based on predetermined image information, and to feed the paper T to the image forming unit and to discharge the paper T on which the toner image is formed. And a paper supply / discharge unit.

  As shown in FIG. 1, the image forming unit includes photosensitive drums 2a, 2b, 2c, and 2d as image carriers (photosensitive members), charging units 10a, 10b, 10c, and 10d, and a laser scanner as an exposure unit. Units 4a, 4b, 4c, 4d, developing devices 16a, 16b, 16c, 16d, toner cartridges 5a, 5b, 5c, 5d, toner supply units 6a, 6b, 6c, 6d, and drum cleaning units 11a, 11b 11c, 11d, static eliminators 12a, 12b, 12c, 12d, intermediate transfer belt 7, primary transfer rollers 37a, 37b, 37c, 37d, secondary transfer roller 8, counter roller 18 and fixing unit 9.

  As shown in FIG. 1, the paper feed / discharge unit includes a paper feed cassette 52, a manual paper feed unit 64, a conveyance path L for paper T, a registration roller pair 80, a first paper discharge unit 50 a, and a second paper feed unit. A paper discharge unit 50b. As will be described later, the transport path L includes a first transport path L1, a second transport path L2, a third transport path L3, a manual transport path La, a return transport path Lb, and a post-processing transport path Lc. Is a collection of

Hereinafter, each configuration of the image forming unit and the paper supply / discharge unit will be described in detail.
First, the image forming unit will be described.
In the image forming unit, charging by the charging units 10a, 10b, 10c, and 10d in order from the upstream side to the downstream side with respect to the respective surfaces of the photosensitive drums 2a, 2b, 2c, and 2d, and the laser scanner units 4a, 4b, 4c, 4d exposure, development devices 16a, 16b, 16c, 16d development, intermediate transfer belt 7 and primary transfer rollers 37a, 37b, 37c, 37d primary transfer, static eliminators 12a, 12b, 12c, 12d And cleaning by the drum cleaning units 11a, 11b, 11c, and 11d.
In the image forming unit, secondary transfer by the intermediate transfer belt 7, the secondary transfer roller 8 and the counter roller 18, and fixing by the fixing unit 9 are performed.

  Each of the photosensitive drums 2a, 2b, 2c, and 2d is formed of a cylindrical member and functions as a photosensitive member or an image carrier. Each of the photosensitive drums 2 a, 2 b, 2 c, and 2 d is disposed so as to be rotatable in the direction of an arrow about an axis that extends in a direction orthogonal to the traveling direction of the intermediate transfer belt 7. An electrostatic latent image is formed on the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d.

  Each of the charging units 10a, 10b, 10c, and 10d is disposed to face the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the charging units 10a, 10b, 10c, and 10d uniformly charges the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d negatively (minus polarity) or positively (plus polarity).

  The laser scanner units 4a, 4b, 4c, and 4d function as exposure units, and are spaced apart from the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the laser scanner units 4a, 4b, 4c, and 4d includes a laser light source (not shown), a polygon mirror, a polygon mirror driving motor, and the like.

  Each of the laser scanner units 4a, 4b, 4c, and 4d scans and exposes the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d based on image information related to the image read by the reading unit 301. Scanning exposure is performed by each of the laser scanner units 4a, 4b, 4c, and 4d, so that charges charged on the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d are removed. Thereby, electrostatic latent images are formed on the respective surfaces of the photosensitive drums 2a, 2b, 2c, and 2d.

  The developing devices 16a, 16b, 16c, and 16d are provided corresponding to the photosensitive drums 2a, 2b, 2c, and 2d, respectively, and are disposed to face the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the developing devices 16a, 16b, 16c, and 16d develops a color toner image by attaching toner of each color to the electrostatic latent images formed on the photosensitive drums 2a, 2b, 2c, and 2d (photosensitive drums). A toner image is formed on the surface). Each of the developing devices 16a, 16b, 16c, and 16d corresponds to four toner colors of yellow, cyan, magenta, and black. Each of the developing devices 16a, 16b, 16c, and 16d includes a developing roller that can be disposed opposite to the surface of the photosensitive drums 2a, 2b, 2c, and 2d, a stirring roller for stirring toner, and the like.

  Each of the toner cartridges 5a, 5b, 5c, and 5d is provided corresponding to each of the developing devices 16a, 16b, 16c, and 16d, and each color toner supplied to each of the developing devices 16a, 16b, 16c, and 16d. To accommodate. Each of the toner cartridges 5a, 5b, 5c, and 5d accommodates yellow toner, cyan toner, magenta toner, and black toner.

  The toner supply units 6a, 6b, 6c, and 6d are provided corresponding to the toner cartridges 5a, 5b, 5c, and 5d and the developing devices 16a, 16b, 16c, and 16d, respectively. The toners of the respective colors accommodated in 5d are supplied to the developing devices 16a, 16b, 16c, and 16d, respectively.

  The toner images of the respective colors developed on the photosensitive drums 2a, 2b, 2c, and 2d are sequentially transferred to the intermediate transfer belt 7. The intermediate transfer belt 7 is stretched around a driven roller 35, a counter roller 18 including a driving roller, a tension roller 36, and the like. Since the tension roller 36 biases the intermediate transfer belt 7 from the inside to the outside, a predetermined tension is applied to the intermediate transfer belt 7.

  Primary transfer rollers 37a, 37b, 37c, and 37d are arranged to face each other on the side opposite to the photosensitive drums 2a, 2b, 2c, and 2d with the intermediate transfer belt 7 interposed therebetween.

  A predetermined portion of the intermediate transfer belt 7 is sandwiched between the primary transfer rollers 37a, 37b, 37c, and 37d and the photosensitive drums 2a, 2b, 2c, and 2d, respectively. The predetermined portion thus sandwiched is pressed against the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d. Primary transfer nips N1a, N1b, N1c, and N1d are formed between the photosensitive drums 2a, 2b, 2c, and 2d and the primary transfer rollers 37a, 37b, 37c, and 37d, respectively. In the primary transfer nips N1a, N1b, N1c, and N1d, the respective color toner images developed on the photosensitive drums 2a, 2b, 2c, and 2d are sequentially transferred to the intermediate transfer belt 7. As a result, a full-color toner image is formed on the intermediate transfer belt 7.

  The primary transfer rollers 37a, 37b, 37c, and 37d are respectively transferred to the intermediate transfer belt 7 with the respective color toner images developed on the photosensitive drums 2a, 2b, 2c, and 2d by a voltage application unit (not shown). The primary transfer bias is applied.

  The static eliminators 12a, 12b, 12c, and 12d are arranged to face the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d, respectively. The static eliminators 12a, 12b, 12c, and 12d respectively irradiate the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d to irradiate light, and the photosensitive drums 2a, 2b, and 2c after the primary transfer is performed. 2d, each surface is neutralized (charge is removed).

  The drum cleaning units 11a, 11b, 11c, and 11d are disposed to face the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d, respectively. Each of the drum cleaning units 11a, 11b, 11c, and 11d removes toner and adhering matter remaining on the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d, and conveys the removed toner to a predetermined recovery mechanism. And collect.

  The secondary transfer roller 8 secondarily transfers the toner image primarily transferred to the intermediate transfer belt 7 onto the paper T. A secondary transfer bias for transferring the toner image formed on the intermediate transfer belt 7 to the paper T is applied to the secondary transfer roller 8 by a voltage application unit (not shown).

  The secondary transfer roller 8 is in contact with or separated from the intermediate transfer belt 7. Specifically, the secondary transfer roller 8 is configured to be movable between a contact position where the secondary transfer roller 8 is in contact with the intermediate transfer belt 7 and a spaced position where the secondary transfer roller 8 is separated from the intermediate transfer belt 7. Specifically, the secondary transfer roller 8 is moved to the contact position when the toner image primarily transferred onto the surface of the intermediate transfer belt 7 is secondarily transferred to the paper T, and is separated from the other position. Moved to.

  On the opposite side of the intermediate transfer belt 7 from the secondary transfer roller 8, a counter roller 18 is disposed. A predetermined portion of the intermediate transfer belt 7 is sandwiched between the secondary transfer roller 8 and the opposing roller 18. Then, the paper T is pressed against the outer surface of the intermediate transfer belt 7 (the surface on which the toner image is primarily transferred). A secondary transfer nip N <b> 2 is formed between the secondary transfer roller 8 and the opposing roller 18. The toner image primarily transferred to the intermediate transfer belt 7 is secondarily transferred to the paper T in the secondary transfer nip N2.

  The fixing unit 9 melts each color toner constituting the toner image secondarily transferred onto the paper T and fixes it on the paper T. The fixing unit 9 includes a heating roller 9a heated by a heater and a pressure roller 9b pressed against the heating roller 9a. The heating roller 9a and the pressure roller 9b sandwich and convey the paper T on which the toner image has been secondarily transferred. When the paper T is conveyed while being sandwiched between the heating roller 9a and the pressure roller 9b, the toner transferred onto the paper T is melted and fixed on the paper T.

Next, the paper supply / discharge unit will be described.
As shown in FIG. 1, in the lower part of the apparatus main body M, two paper feed cassettes 52 that store paper T are arranged in an up-down direction. The paper feed cassette 52 is configured to be pulled out from the housing of the apparatus main body M in the horizontal direction. In the paper feed cassette 52, a placement plate 60 on which the paper T is placed is disposed. In the paper feed cassette 52, the paper T is stored in a state of being stacked on the placement plate 60. The paper T placed on the placement plate 60 is sent out to the transport path L by the cassette paper feed unit 51 arranged at the end of the paper feed cassette 52 on the paper feed side (the left end in FIG. 1). The cassette paper feed unit 51 includes a double feed prevention mechanism including a forward feed roller 61 for taking out the paper T on the placement plate 60 and a paper feed roller pair 63 for feeding the paper T to the transport path L one by one. Prepare.

  A manual paper feed unit 64 is provided on the right side surface (right side in FIG. 1) of the apparatus main body M. The manual paper feed unit 64 is provided mainly for supplying the apparatus main body M with a paper T of a size and type different from the paper T set in the paper feed cassette 52. The manual paper feed unit 64 includes a manual feed tray 65 that forms a part of the apparatus main body M in the closed state, and a paper feed roller 66. The lower end of the manual feed tray 65 is attached to the vicinity of the paper feed roller 66 so as to be rotatable (openable and closable). The paper T is placed on the open manual feed tray 65. The manual paper feed unit 64 feeds the paper T placed on the open manual feed tray 65 to the manual feed path La.

  A first paper discharge unit 50 a and a second paper discharge unit 50 b are provided on the upper side of the apparatus main body M. The first paper discharge unit 50a and the second paper discharge unit 50b discharge the paper T to the outside of the apparatus main body M. Details of the first paper discharge unit 50a and the second paper discharge unit 50b will be described later.

  The conveyance path L for conveying the paper T includes a first conveyance path L1 from the cassette paper feeding unit 51 to the secondary transfer roller 8, a second conveyance path L2 from the secondary transfer roller 8 to the fixing unit 9, and a fixing unit. 9 to the first paper discharge section 50a, the manual conveyance path La for joining the paper supplied from the manual paper feed section 64 to the first conveyance path L1, and the third conveyance path L3 on the upstream side. The paper transported from the upstream side to the downstream side is reversed and returned to the first transport path L1, and the paper transported from the upstream side to the downstream side of the third transport path L3 is sent to the post-processing device (not shown). And a post-processing conveyance path Lc for conveyance.

Moreover, the 1st junction part P1 and the 2nd junction part P2 are provided in the middle of the 1st conveyance path L1. A first branch portion Q1 is provided in the middle of the third transport path L3.
The first joining part P1 is a joining part where the manual feed path La joins the first transport path L1. The second junction P2 is a junction where the return conveyance path Lb merges with the first conveyance path L1.
The first branch portion Q1 is a branch portion where the post-processing transport path Lc branches from the third transport path L3. A rectifying member 58 is provided in the first branch portion Q1. The rectifying member 58 rectifies the transport direction of the paper T carried out from the fixing unit 9 to the third transport path L3 toward the first paper discharge section 50a or the post-processing transport path Lc toward the second paper discharge section 50b ( Switch).

  In the middle of the first transport path L1 (specifically, between the second joining portion P2 and the secondary transfer roller 8), a sensor for detecting the paper T and correction of the skew (oblique paper feeding) of the paper T In addition, a registration roller pair 80 for adjusting the timing with the toner image is disposed. The sensor is disposed immediately before (on the upstream side) the registration roller pair 80 in the transport direction of the paper T. The registration roller pair 80 is a pair of rollers that convey the paper T by performing the above-described correction and timing adjustment based on detection signal information from the sensor.

  The return conveyance path Lb is a conveyance provided to make the opposite surface (non-printing surface) opposite to the already printed surface opposite to the photosensitive drums 2a, 2b, 2c, and 2d when performing duplex printing on the paper T. Road. According to the return transport path Lb, the paper T transported from the first branching section Q1 to the paper discharge section 50 is turned upside down and returned to the first transport path L1 and arranged upstream of the secondary transfer roller 8. It can be conveyed to the upstream side of the pair of registration rollers 80. A predetermined toner image is transferred onto the non-printing surface by the photosensitive drums 2a, 2b, 2c, and 2d on the paper T that has been turned upside down by the return conveyance path Lb.

  A first paper discharge unit 50a is formed at the end of the third transport path L3. The first paper discharge unit 50 a is disposed on the upper side of the apparatus main body M. The first paper discharge unit 50a is open toward the right side surface of the apparatus main body M (the right side in FIG. 1, the manual paper feed unit 64 side). The first paper discharge unit 50a discharges the paper T transported through the third transport path L3 to the outside of the apparatus main body M.

  On the opening side of the first paper discharge section 50a, a paper discharge stacking section M1 is formed. The paper discharge stacking unit M1 is formed on the upper surface (outer surface) of the apparatus main body M. The paper discharge stacking unit M1 is a part formed by the upper surface of the apparatus main body M being depressed downward. The bottom surface of the paper discharge stacking unit M1 constitutes part of the top surface of the apparatus main body M. In the paper discharge stacking unit M1, sheets T onto which a predetermined toner image is transferred and discharged from the first paper discharge unit 50a are stacked and stacked.

A second paper discharge unit 50b is formed at the end of the post-processing conveyance path Lc. The second paper discharge unit 50b is disposed on the upper side of the apparatus main body M. The second paper discharge section 50b opens toward the left side of the apparatus main body M (left side in FIG. 1, the side to which the post-processing apparatus is connected). The second paper discharge unit 50b discharges the paper T conveyed through the post-processing conveyance path Lc to the outside of the apparatus main body M.
A post-processing device (not shown) is connected to the opening side of the second paper discharge unit 50b. The post-processing device performs post-processing (stapling, punching, etc.) of paper ejected from the image forming apparatus (copy machine 1).
A paper detection sensor is disposed at a predetermined position on each conveyance path.

Next, a paper jam (JAM) in the main transport path L1 to L3 (the first transport path L1, the second transport path L2, and the third transport path L3 are collectively referred to as “main transport path” hereinafter) and the return transport path Lb. A structure for eliminating the problem will be briefly described.
As shown in FIG. 1, on the left side surface (left side in FIG. 1) of the apparatus main body M, main conveyance paths L1 to L3 and a return conveyance path Lb are arranged in parallel so as to mainly extend in the vertical direction. A cover body 40 is provided on the left side of the apparatus body M (left side in FIG. 1) so as to form a part of the side surface of the apparatus body M. The cover body 40 is connected to the apparatus main body M via a fulcrum shaft 43 at the lower end thereof. The fulcrum shaft 43 is disposed along the direction in which the axial direction crosses the main transport paths L1 to L3 and the return transport path Lb. The cover body 40 is configured to be rotatable between a closed position (position shown in FIG. 1) and an open position (not shown) with the fulcrum shaft 43 as a center.

  The cover body 40 includes a first cover portion 41 that is rotatably connected to the apparatus main body M by a fulcrum shaft 43, and a second cover portion 42 that is rotatably connected to the apparatus main body M by the same fulcrum shaft 43. It consists of and. The first cover portion 41 is located on the outer side (side surface side) of the apparatus main body M than the second cover portion 42. In FIG. 1, the hatched portion with the left-down dashed line is the first cover portion 41, and the hatched portion with the right-down dashed line is the second cover portion 42.

In the state where the cover body 40 is located at the closed position, the outer surface side of the first cover portion 41 forms a part of the outer surface (side surface) of the apparatus main body M.
Further, in the state where the cover body 40 is located at the closed position, the inner surface side (the apparatus main body M side) of the second cover portion 42 forms a part of the main transport paths L1 to L3.
Further, in a state where the cover body 40 is located at the closed position, the inner surface side of the first cover portion 41 and the outer surface side of the second cover portion 42 form at least a part of the return conveyance path Lb. That is, the return conveyance path Lb is formed between the first cover part 41 and the second cover part 42.

  The copying machine 1 of the present embodiment includes the cover body 40 having such a configuration, so that when a paper jam (JAM) occurs in the main transport paths L1 to L3, the cover body 40 is closed as shown in FIG. By rotating from the position to an open position (not shown) to open the main transport paths L1 to L3, it is possible to process paper jammed in the main transport paths L1 to L3. On the other hand, when a paper jam occurs in the return conveyance path Lb, the cover body 40 is rotated to the open position, and then the second cover portion 42 is moved to the apparatus main body M side (right side in FIG. ) To open the return conveyance path Lb, the paper jammed in the return conveyance path Lb can be processed.

  Next, the reading unit 301 of the image reading apparatus 300 will be described in detail with reference to FIGS. FIG. 2 is a plan view showing an outline of the internal structure of the reading unit 301 of the image reading apparatus 300. FIG. 3 is a diagram of the reading unit 301 of the image reading apparatus 300 viewed from the main scanning direction Y. FIG. 4 is a diagram showing an outline of the moving mechanism 370 of the illumination unit 347 and the mirror unit 349.

  As shown in FIGS. 2 and 3, the reading unit 301 includes a housing 306, a first contact glass 335A that forms a first reading surface 302A, a second contact glass 335B that forms a second reading surface 302B, Is provided. In addition, the reading unit 301 moves a pair of guide rails 345, an illumination unit 347, a mirror unit 349, and the pair of guide units that move the illumination unit 347 and the mirror unit 349 in the sub-scanning direction X in the internal space 304 of the housing 306. A unit moving mechanism 370, an imaging lens 357, a CCD 358 as a reading unit, and an optical sensor 362 are provided.

  The housing 306 has an opening corresponding to the first contact glass 335A and the second contact glass 335B on the upper side. This opening region is covered with the first contact glass 335A and the second contact glass 335B.

  As shown in FIG. 2, the pair of guide rails 345 are disposed between the right side surface 306 a and the left side surface 306 b along the main scanning direction Y in the housing 306. The pair of guide rails 345 are arranged so as to extend in the sub-scanning direction X from the front surface 306 c and the back surface 306 d along the sub-scanning direction X with an interval inside the main scanning direction Y. The pair of guide rails 345 are installed in parallel with the first contact glass 335A and the second contact glass 335B. On the pair of guide rails 345, the first frame 311 of the illumination unit 347 and the second frame 312 of the mirror unit 349 are mounted so as to be movable in the sub-scanning direction X.

As shown in FIG. 2, the pair of unit moving mechanisms 370 are respectively provided between the front surface 306c of the reading unit 301 and one guide rail 345 and between the other guide rail 345 of the back surface 306d of the reading unit 301. Be placed. The pair of unit moving mechanisms 370 are configured line-symmetrically in the main scanning direction Y.
Details of the unit moving mechanism 370 will be described later.

  As illustrated in FIG. 3, the illumination unit 347 includes an illumination unit 340, a first mirror 321, and a first frame 311 that houses the illumination unit 340 and the first mirror 321.

  The illumination unit 340 includes an LED unit 500 to which a plurality of LEDs 501 are attached. The illumination unit 340 irradiates the document reading position R with light H0. The first mirror 321 is disposed on the lower side in the vertical direction Z of the illumination unit 347. The first mirror 321 is arranged so that the reflection surface faces the document G and the second mirror 322 side. The first mirror 321 reflects the light beam H 1 from the document to the second mirror 322.

  As shown in FIG. 3, the mirror unit 349 includes a second mirror 322, a third mirror 323, and a second frame 312 that accommodates the second mirror 322 and the third mirror 323.

  The second mirror 322 is disposed on the upper side in the vertical direction Z of the second frame 312. The second mirror 322 is arranged so that the reflection surface faces the first mirror 321 and the third mirror 323 side. The second mirror 322 reflects the light beam H2 from the first mirror 321 to the third mirror 323 side.

  The third mirror 323 is disposed on the lower side in the vertical direction Z of the second frame 312. The third mirror 323 is arranged so that the reflection surface faces the second mirror 322 and the imaging lens 357 side. The third mirror 323 reflects the light beam H3 from the second mirror 322 to the imaging lens 357 side.

  As shown in FIGS. 2 and 3, an ISU base 356 that is a member that supports the imaging lens 357, the CCD 358, and the like is attached to the bottom surface 306e of the reading unit 301 near the right side surface 306a. An imaging lens 357 and a CCD 358 as a reading unit are attached to the upper surface of the ISU base 356 in a predetermined positional relationship.

  The imaging lens 357 is installed on a lens support 359 that is fixed to the ISU base 356. The lens support base 359 is disposed such that its position can be adjusted by a guide member 360 disposed on the CCD 358 side. The imaging lens 357 is disposed at the approximate center in the main scanning direction Y of the reading unit 301. The imaging lens 357 is disposed on the end side opposite to the original G side in the optical path H. The imaging lens 357 forms an image of the incident light beam H4 at a predetermined position. That is, the imaging lens 357 forms an image of the original G at a predetermined position.

  The CCD 358 is mounted on a CCD substrate 361 disposed on the back side of the guide member 360. The CCD 358 is disposed at an image forming position in the image forming lens 357. The light beam from the imaging lens 357 is incident on the CCD 358 through the opening window 360 a formed near the center of the guide member 360. The optical axis of the light beam incident on the CCD 358 is corrected by finely adjusting the position of the guide member 360.

  The optical sensor 362 is disposed on the ISU base 356. The optical sensor 362 detects the size of the document G along the sub-scanning direction X depending on whether or not the reflected light from the document G placed on the contact glass 335 is received.

Next, the unit moving mechanism 370 will be described in detail.
2 and 4, the unit moving mechanism 370 includes a driving wire 371, a first fixed member 372, a first connecting member 373, a first movable pulley 374, a second connecting member 375, The first fixed pulley 376, the drive pulley 377, the second fixed pulley 378, the second movable pulley 379, the third fixed pulley 380, the elastic member 381, and the second fixed member 382 are provided.

  The fixing members 372 and 382 are fixed to the bottom surface 306e of the housing 306. The movable pulleys 374 and 379 are fixed to the first frame 311 of the mirror unit 349 so that the rotation axis extends in the main scanning direction Y. The pulleys 376, 377, and 378 are fixed to the housing 306 so that the rotation shaft extends in the main scanning direction Y. The third fixed pulley 380 is fixed to the housing 306 so that the rotation axis extends in the vertical direction Z.

  One end of the driving wire 371 is connected to the first fixing member 372 by the first connecting member 373. The other end of the drive wire 371 is connected to the second fixing member 382 through an elastic member 381. An intermediate portion of the driving wire 371 is connected to the first frame 311 of the lighting unit 347 by the second connecting member 375 and is also stretched over each movable pulley and each fixed pulley. The drive wire 371 is driven by a drive pulley 377.

  The first fixed pulley 376 is disposed in the vicinity of the right side surface 306 a of the housing 306. The second fixed pulley 378 is disposed in the vicinity of the left side surface 306 b of the housing 306. The third fixed pulley 380 is disposed in the vicinity of the left side surface 306 b of the reading unit 301. The first fixing member 372 is disposed between the first fixed pulley 376 and the second fixed pulley 378 in the sub scanning direction X. The first connecting member 373 connects one end of the driving wire 371 and the first fixing member 372. The second fixing member 382 is disposed on the inner side in the main scanning direction Y than the third fixing pulley 380. The elastic member 381 connects the end of the drive wire 371 and the third fixed pulley 380 so that an elastic force appears in the main scanning direction Y.

The first movable pulley 374 and the second movable pulley 379 are fixed outside the main scanning direction Y in the second frame 312 of the mirror unit 349. The first movable pulley 374 and the second movable pulley 379 are disposed between the first fixed pulley 376 and the second fixed pulley 378 and the third fixed pulley 380 in the sub-scanning direction X.
The second connecting member 375 is provided on the first frame 311 of the lighting unit 347 and connects the first frame 311 and the drive wire 371. The second connecting member 375 is disposed between the first fixed pulley 376 and the first movable pulley 374 and the second movable pulley 379.

  The drive wire 371 is spanned as follows. Specifically, one end of the driving wire 371 is connected to the first fixing member 372 by the first connecting member 373, extends to the left side 306b side of the housing 306, and from the lower side to the left of the first movable pulley 374. It is hung on the half circumferential surface, extends from the upper side of the first movable pulley 374 to the right side surface 306a side of the housing 306, and is connected to the first frame 311 by the second connecting member 375. The drive wire 371 extends from the first frame 311 to the right side 306a side of the housing 306, is hung from the upper side to the right half circumferential surface of the first fixed pulley 376, and from the lower side of the first fixed pulley 376. It extends to the left side 306b side of the body 306 and is hung from the lower side on the left half circumferential surface of the second fixed pulley 378. The drive wire 371 extends from the upper side of the second fixed pulley 378 to the right side surface 306 a, is hung from the lower side on the right half circumferential surface of the second movable pulley 379, and the housing 306 from the upper side of the second movable pulley 379. Extends to the left side surface 306b side, is hung on the third fixed pulley 380, and extends inward in the main scanning direction Y. Furthermore, the other end of the drive wire 371 is connected to the second fixing member 382 via an elastic member 381.

  In the pair of unit moving mechanisms 370, the respective drive pulleys 377 are connected by a drive shaft 383 extending in the main scanning direction Y. One drive pulley 377 is driven forward or reverse by a drive motor (not shown). Thus, when one drive pulley 377 rotates, the other drive pulley 377 also rotates in synchronization with this rotation.

  As the driving pulley 377 rotates, the driving wire 371 moves in the sub-scanning direction X toward the right side 306a or the left side 306b of the housing 306. As the driving wire 371 moves, the illumination unit 347 and the mirror unit 349 move in the sub-scanning direction X along the guide rail 345. The illumination unit 347 (first frame 311) is connected to the drive wire 371, whereas the mirror unit 349 includes a first movable pulley 374 that is a movable pulley provided on the second frame 312 and A drive wire 371 is stretched over the second movable pulley 379. Therefore, the ratio of the moving distance of the illumination unit 347 and the moving distance of the mirror unit 349 is 2: 1.

  In the present embodiment, a configuration in which the ratio between the moving distance of the illumination unit 347 and the moving distance of the mirror unit 349 is 2: 1 is realized using the principle of a moving pulley. Not. For example, a configuration in which the ratio of the moving distance of the illumination unit 347 and the moving distance of the mirror unit 349 is 2: 1 can be realized by using a driving pulley and a driven pulley having a large diameter portion and a small diameter portion.

  Next, the configuration related to the control of the light emission amounts of the plurality of LEDs 501 in the image reading apparatus 300 will be described in detail with reference to FIGS. 3 and 5 to 7. FIG. 5 is a diagram schematically showing the structure around the document reading position R of the image reading apparatus 300. FIG. 6 is a perspective view showing an illumination unit 340 including the LED unit 500. FIG. 7 is a functional block diagram illustrating functions of the image reading apparatus 300 according to the first embodiment. FIG. 8 is a diagram illustrating an example of the relationship between the state of the paper T at the original reading position R, the reading density, the light amount, and the arrangement of the LEDs 501. FIG. 9 is a diagram illustrating another example of the relationship between the state of the paper T at the original reading position R, the reading density, the light amount, and the arrangement of the LEDs 501.

  As shown in FIG.5 and FIG.6, the illumination part 340 is comprised from the two LED units 500 as a light emission part. The LED unit 500 includes a substrate member 503 and one LED row mounted on one surface of the substrate member 503. One LED row is formed by arranging a plurality of LEDs 501 in the main scanning direction Y at regular intervals. Each LED 501 in the LED unit 500 emits light (emits light). As will be described later, the LED unit 500 is configured to be able to change the light emission amounts of the plurality of LEDs 501.

  As shown in FIG. 3, the LED unit 500 is attached to the first frame 311 so that the light H <b> 0 emitted from each LED 501 irradiates the document reading position R. According to the illumination unit 340, the light H0 is irradiated from one LED unit 500 to the original G located at the original reading position R, and the light H0 is applied from the other LED unit 500 to the original G located at the original reading position R. Irradiated.

Next, the document conveying unit 70 will be described in detail.
As shown in FIG. 5, the document conveyance unit 70 includes a document guide 711, a pre-reading roller pair 712, a post-reading roller pair 713, a transparency sensor 440, and a glossiness sensor 450. .

  The document guide 711 faces the first reading surface 302A of the first contact glass 335A at the document reading position R, and is spaced apart from the first reading surface 302A with a minute gap. A transport path for the document G and a document reading position R are formed between the document guide 711 and the first reading surface 302A.

The pre-reading roller pair 712 is a roller pair provided upstream of the document reading position R, and feeds the conveyed document G to the document reading position R.
The post-reading roller pair 713 is a roller pair provided on the downstream side of the document reading position R, and feeds the document G positioned at the document reading position R to the downstream side.

A transparency sensor 440 is disposed between the original reading position R and the pre-reading roller pair 712 in the conveyance path of the original G. A glossiness sensor 450 is disposed on the downstream side of the pre-reading roller pair 712.
In addition, an inclined member 334 having an inclined surface that is inclined upward toward the upstream side is provided between the post-reading roller pair 713 and the original reading position R in the conveyance path of the original G. The inclined member 334 is disposed between the first contact glass 335A and the second contact glass 335B in the sub-scanning direction X. According to the inclined member 334, the document G that has passed through the document reading position R is fed obliquely upward and is directed toward the post-reading roller pair 713.

Next, functions of the image reading apparatus 300 according to the first embodiment will be described with reference to a functional block diagram shown in FIG.
As shown in FIG. 7, the image reading apparatus 300 includes a control unit 410, a memory 420, a document state setting unit 430, a transparency sensor 440, a glossiness sensor 450, and an LED unit 500.

  The memory 420 stores predetermined data. For example, the memory 420 includes application programs that operate various functions and various storage units that store various data. Specifically, the memory 420 includes a light emission amount control pattern storage unit 421 that stores a light emission amount control pattern used when the light emission amount of the LED 501 is controlled by the first light emission amount control unit 411 as a light emission amount control unit. .

The control unit 410 controls the entire image reading apparatus 300. For example, the control unit 410 functions as the first light emission amount control unit 411 and controls the light emission amount of the LED 501 of the LED unit 500 with reference to the light emission amount control pattern stored in the light emission amount control pattern storage unit 421.
Details of the first light emission amount control unit 411 will be described later.

  The document state setting unit 430 sets the state of the document G before the document transport unit 70 starts transporting the document G. The document state setting unit 430 is provided, for example, on an operation panel (not shown) provided on the upper surface of the apparatus main body M. According to the document state setting unit 430, for example, when the user knows the state of the document G (for example, the thickness of the document G) in advance, the user operates the document state setting unit 430 to determine the state of the document G. Can be set. The state signal of the original G set by the original state setting unit 430 is output to the control unit 410.

Both the transparency sensor 440 and the glossiness sensor 450 function as a first document state detection unit, and detect the state of the document G being conveyed to the document reading position R by the document conveyance unit 70.
It is preferable that the state of the document is detected based on a region in the vicinity of the upstream end in the transport direction of the document G and / or a region in the vicinity of the downstream end. This is because printing (image formation) is often not performed in this area, and it is easy to accurately detect the state of the document. In order to improve the detection accuracy of the original state, it is preferable that the number of times of detecting the original state is larger.

  As shown in FIG. 5, the transparency sensor 440 is a sensor that detects the transparency of the document G that is being transported to the document reading position R by the document transport unit 70. The transmittance sensor 440 includes a light emitting element 441 and a light receiving element 442. The light emitting element 441 and the light receiving element 442 are arranged with the original G interposed therebetween. Therefore, the light transmitted from the light emitting element 441 and transmitted through the original G can be received by the light receiving element 442. The transmittance sensor 440 determines the transmittance of the original G positioned between the light emitting element 441 and the light receiving element 422 based on the amount of light emitted from the light emitting element 441 (the amount of received light). Can be detected. This is because if the amount of received light is large, the transparency of the original G is high, while if the amount of received light is small, the transparency of the original G is low.

In the document conveying unit 70, the thickness of the document G is detected by using the transparency detection function of the transparency sensor 440. This is because the transparency is low when the thickness of the original G is high, while the transparency is high when the thickness of the original G is thin. Therefore, the thickness of the document G can be detected based on the transparency of the document G detected by the transparency sensor 440.
A signal of the transparency (thickness) of the original G detected by the transparency sensor 440 is output to the control unit 410.

  As shown in FIG. 5, the glossiness sensor 450 is a sensor that detects the glossiness of the document G that is being transported to the document reading position R by the document transport unit 70. The glossiness sensor 450 includes a light emitting element 451 and a light receiving element 452. Both the light emitting element 451 and the light receiving element 452 are located on the side of the original G facing the printing surface (surface on which an image is formed). Therefore, the reflected light emitted from the light emitting element 451 and reflected by the original G can be received by the light receiving element 452.

  The glossiness sensor 450 can determine the glossiness as follows. More specifically, the gloss level is a print received by the light receiving element 452 with respect to the intensity of light (incident light) incident on the printing surface of the original G after being emitted from the light emitting element 451 at a predetermined angle (for example, 60 degrees). It can be determined from the ratio of the intensity of light reflected from the surface (reflected light). This is because the glossiness of the original G is low if the amount of reflected light received by the light receiving element 452 is large, while the glossiness of the original G is high if the amount of reflected light received by the light receiving element 452 is small.

  The first light emission amount control unit 411 controls the light emission amounts of the plurality of LEDs 501 based on the state of the original G being conveyed to the original reading position R by the original conveying unit 70. Specifically, the first light emission amount control unit 411 determines the light emission amounts of the plurality of LEDs 501 based on the state of the original G detected by the first original state detection unit (the transparency sensor 440 and the glossiness sensor 450). Control.

  Further, the first light emission amount control unit 411 controls the light emission amounts of the plurality of LEDs 501 based on the state of the original G set by the original state setting unit 430.

  As a control pattern of the light emission amount of the LED 501 by the first light emission amount control unit 411, a pattern is set that reduces unevenness of the reading density of the original G for each state (thickness, glossiness, etc.) of the original G. The control pattern can be determined, for example, by repeatedly measuring, using the actual device of the image reading apparatus 300, a pattern that reduces unevenness in the reading density of the original G for each state of the original G.

  For example, as shown in FIG. 8, when the document G is relatively thick paper, the vicinity of both ends of the document G in the width direction (main scanning direction Y) is separated from the first reading surface 302A (first contact glass 335A). When there is a tendency, the LED 501 is controlled so that the light emission amount of the LED 501 that irradiates the vicinity of both ends in the width direction of the document G among the plurality of LEDs 501 arranged in the main scanning direction Y is controlled.

  As shown in FIG. 9, when the document G is relatively thin paper, the vicinity of the central portion in the width direction (main scanning direction Y) of the document G is separated from the first reading surface 302A (first contact glass 335A). When there is a tendency, the LED 501 is controlled so that the light emission amount of the LED 501 that irradiates the vicinity of the central portion in the width direction of the document G among the plurality of LEDs 501 arranged in the main scanning direction Y is increased.

  Further, when the glossiness is high, the amount of reflected light reflected by the original G is small, so the LED 501 is controlled so that the light emission amount of the LED 501 increases. On the other hand, when the glossiness is low, the amount of reflected light reflected by the original G increases, so that the LED 501 is controlled so that the light emission amount of the LED 501 decreases.

  The control pattern for reducing the unevenness of the reading density of the original G described above is an example, and may vary depending on the configuration of the image reading apparatus 300 and the like. For example, when the document G is a relatively thick paper, the vicinity of the central portion in the width direction of the document G may tend to move away from the first reading surface 302A, and when the document G is a relatively thin paper, There may be a tendency that the vicinity of both ends in the width direction of the original G is separated from the first reading surface 302A. Accordingly, a control pattern for reducing unevenness in the reading density of the original G is set as appropriate for each type (model) of the image reading apparatus.

The operation of the image reading apparatus 300 in this embodiment will be described.
First, a case where the document G is read using the document conveyance unit 70 will be described.
First, the document conveying unit 70 (see FIG. 1) is closed. When the original G is placed on the original placing portion 71, the sensor 362 (not shown) detects that the original G is placed on the original placing portion 71, whereby the illumination unit 347 and the mirror unit 349 (FIG. 3). Is located at the first reading position (see FIG. 1) on the left side 306b side of the housing 306.

  Next, a start switch (not shown) is pressed to instruct the color copier 1 to duplicate the image of the original G. By pressing the start switch, the image reading apparatus 300 starts reading an image of the original G.

  Specifically, first, the document G placed on the document placement unit 71 is conveyed to the document reading position R. In addition, the plurality of LEDs 501 in the LED unit 500 are turned on. Light H0 emitted from the plurality of lit LEDs 501 illuminates the document reading position R at a predetermined angle. Accordingly, the original reading position R is irradiated with line-shaped light extending in the main scanning direction Y from both sides in the sub-scanning direction X.

  In a state where the document reading position R is irradiated with light, each of the illumination unit 347 and the mirror unit 349 does not move in the sub-scanning direction X. Therefore, each of the illumination unit 347 and the mirror unit 349 keeps the optical path length in the optical path H constant.

  The image light beam H from the original G is reflected by the first mirror 321, the second mirror 322, and the third mirror 323 and then enters the imaging lens 357 (see FIG. 3).

  The imaging lens 357 forms an image of the original G on the light receiving surface of the CCD 358. The CCD 358 converts the image information of the original G formed on the light receiving surface into an electric signal and reads it (see FIG. 3).

  Image information read by the CCD 358 is output to the CCD substrate 361. The image information output to the CCD substrate 361 is output to the apparatus main body M via a predetermined circuit board (see FIG. 3).

  In the apparatus main body M, the input image information is input to an image formation control unit (not shown). Based on the image information, the image forming control unit includes the photosensitive drums 2a to 2d as the image carrier constituting the image forming unit, the charging units 10a to 10d, the laser scanner units 4a to 4d, the developing devices 16a to 16d, and the like. Control. A predetermined toner image is formed on the photosensitive drums 2a, 2b, 2c, and 2d based on the image information (see FIG. 1).

  On the paper T conveyed to the primary transfer nips N1a, N1b, N1c, and N1d formed by the photosensitive drums 2a, 2b, 2c, and 2d via the conveyance path L, the image of the original G and The same image is transferred. The paper T on which the image is formed is discharged from the first paper discharge unit 50a and the second paper discharge unit 50b to the outside of the apparatus main body M (see FIG. 1).

  Next, a case where the document G is read without using the document conveyance unit 70 will be described. First, the document conveying unit 70 (see FIG. 1) is opened, and the document G is placed on the second reading surface 302B (see FIG. 3). When the optical sensor 362 (see FIG. 3) detects that the document is placed on the second reading surface 302B, the illumination unit 347 and the mirror unit 349 (see FIG. 3) are connected to the left side surface 306b of the housing 306. Arranged on the side (see FIG. 3).

  Next, the document conveyance unit 70 is closed. Then, by pressing a start switch (not shown), the color copying machine 1 is instructed to duplicate the image of the original G. By pressing the start switch, the image reading apparatus 300 starts reading an image of the original G.

  Specifically, first, the plurality of LEDs 501 in the LED unit 500 are turned on. Light H0 emitted from the plurality of lit LEDs 501 illuminates the document reading position R at a predetermined angle. Accordingly, the original reading position R is irradiated with line-shaped light extending in the main scanning direction Y from both sides in the sub-scanning direction X.

  In a state where the document reading position R is irradiated with light, each of the illumination unit 347 and the mirror unit 349 moves in the sub-scanning direction X. Each of the illumination unit 347 and the mirror unit 349 moves while keeping the optical path length in the optical path H constant.

  The image light beam H from the original G is reflected by the first mirror 321, the second mirror 322, and the third mirror 323 and then enters the imaging lens 357 (see FIG. 3).

  The imaging lens 357 forms an image of the original G on the light receiving surface of the CCD 358. The CCD 358 converts the image information of the original G formed on the light receiving surface into an electric signal and reads it (see FIG. 3).

  Image information read by the CCD 358 is output to the CCD substrate 361. The image information output to the CCD substrate 361 is output to the apparatus main body M via a predetermined circuit board (see FIG. 3).

  In the apparatus main body M, the input image information is input to an image formation control unit (not shown). Based on the image information, the image forming control unit includes the photosensitive drums 2a to 2d as the image carrier constituting the image forming unit, the charging units 10a to 10d, the laser scanner units 4a to 4d, the developing devices 16a to 16d, and the like. Control. A predetermined toner image is formed on the photosensitive drums 2a, 2b, 2c, and 2d based on the image information (see FIG. 1).

  On the paper T conveyed to the primary transfer nips N1a, N1b, N1c, and N1d formed by the photosensitive drums 2a, 2b, 2c, and 2d via the conveyance path L, the image of the original G and The same image is transferred. The paper T on which the image is formed is discharged from the first paper discharge unit 50a and the second paper discharge unit 50b to the outside of the apparatus main body M (see FIG. 1).

  Next, the control flow of the light emission amounts of the plurality of LEDs 501 by the first light emission amount control unit 411 in the first embodiment will be described with reference to FIG. FIG. 10 is a flowchart illustrating the operation of the image reading apparatus 300 according to the first embodiment.

  As shown in FIG. 10, in step ST <b> 11, the operation of conveying the original G in the original conveying unit 70 is started, and the original G placed on the original placing unit 71 is conveyed toward the original reading position R.

  In step ST12, when the original G passes the detectable position in the glossiness sensor 450, the glossiness sensor 450 detects the glossiness of the original G. The detected gloss level signal is output to the first light emission amount control unit 411.

  In step ST13, when the document G passes through the detectable position in the transparency sensor 440, the transparency sensor 440 detects the transparency of the document G. The detected transmittance signal is output to the first light emission amount control unit 411. In the first light emission amount control unit 411, the thickness of the original G is obtained from the transmittance.

  In step ST <b> 14, the first light emission amount control unit 411 refers to the light emission amount control pattern storage unit 421 of the memory 420 and controls the light emission amount corresponding to the detected transmittance and thickness (transmittance) of the document G. Determine the pattern.

  In step ST15, the first light emission amount control unit 411 controls the light emission amount of the LED 501 based on the determined light emission amount control pattern.

  In step ST16, the image of the original G is read by the CCD 358 based on the reflected light from the LED unit 500 (illumination unit 340) in which the light emission amount of the LED 501 is controlled.

According to the first embodiment, for example, the following effects are exhibited.
The image reading apparatus 300 according to the first embodiment includes a document conveying unit 70 that conveys a document G to a predetermined document reading position R, and a plurality of LEDs 501 that emit light H0 that irradiates the document G located at the document reading position R. And an LED unit 500 that is arranged at a predetermined interval in the main scanning direction Y and configured to change the light emission amounts of the plurality of LEDs 501.

  Therefore, according to the image reading apparatus 300 of the first embodiment, based on the state of the document G being transported to the document reading position R by the document transport unit 70 or the state of the document G positioned at the document reading position R, By changing the light emission amounts of the plurality of LEDs 501, unevenness in the reading density of the original G can be reduced. For example, regarding the LED 501 corresponding to the region where the reading density of the original G is high, the reading density in this region can be lowered by increasing the light emission amount. In this way, the reading density of the original G can be made uniform and unevenness can be reduced.

  In addition, the image reading apparatus 300 according to the first embodiment controls the light emission amount of each of the plurality of LEDs 501 based on the state of the document G being conveyed to the document reading position R by the document conveying unit 70. A part 411 is further provided. Therefore, according to the image reading apparatus 300 of the first embodiment, before the document G is transported to the document reading position R by the document transport unit 70, a plurality of light emission amounts are controlled based on the state of the document G by the first light emission amount control unit 411. The amount of light emitted from each LED 501 can be controlled. Accordingly, it is possible to secure a processing time for determining the light emission amount control pattern, and to reduce the reading density of the original G with high accuracy.

  The image reading apparatus 300 according to the first embodiment further includes a glossiness sensor 450 and a transparency sensor 440 that detect the state of the original G that is being conveyed to the original reading position R by the original conveying section 70. The light emission amount control unit 411 controls the light emission amounts of the plurality of LEDs 501 based on the document state (glossiness and thickness) detected by the glossiness sensor 450 and the transparency sensor 440, respectively. Therefore, according to the image reading apparatus 300 of the first embodiment, the first light emission amount control unit 411 controls the light emission amounts of the plurality of LEDs 501 based on the state of the document G without any special operation by the user. be able to. Therefore, the reading density of the original G can be reduced easily and with high accuracy.

  The image reading apparatus 300 according to the first embodiment further includes a document state setting unit 430 that sets the state of the document G before the document transport unit 70 starts transporting the document G, and includes a first light emission amount control unit. Reference numeral 411 controls the light emission amounts of the plurality of LEDs 501 based on the state of the original G set by the original state setting unit 430. Therefore, according to the image reading apparatus 300 of the first embodiment, for example, when the user knows the thickness and glossiness of the document G in advance as the document state, the thickness and glossiness are set by the user's operation. can do. Therefore, the reading density of the original G can be reduced with high accuracy.

  In the image reading apparatus 300 according to the first embodiment, the state of the document is detected based on a region in the document near the upstream end and / or a region in the downstream end. Since these areas are often not printed (image formation), it is possible to detect the state of the original with high accuracy and stability compared to the case where the state of the original is detected based on the printed area. .

  Next, another embodiment of the present invention will be described. As for another embodiment, the points different from the first embodiment will be mainly described, the same reference numerals are given to the same configurations as those of the first embodiment, and the description will be omitted. The description of the first embodiment is applied as appropriate to points that are not particularly described in the other embodiments. Also in another embodiment, the same effect as the first embodiment is exhibited.

  Next, a second embodiment will be described. FIG. 11 is a functional block diagram illustrating functions of the image reading apparatus 300 according to the second embodiment. FIG. 12 is a perspective view showing a CCD 358 in the second embodiment. FIG. 13A is a diagram showing the relationship between the optical path H and the CCD 358 in the second embodiment, and FIG. 13B is a partially enlarged view of FIG. 13A.

The first embodiment controls the amount of light emitted from the plurality of LEDs 501 based on the state of the document G that is being transported to the document reading position R by the document transport unit 70, whereas the second embodiment is configured to read the document. The main difference from the first embodiment is that the light emission amounts of the plurality of LEDs 501 are controlled based on the state of the document G located at the position R. Other configurations are the same as those of the first embodiment.
As described above, the second embodiment is mainly different from the first embodiment in the configuration related to the control of the light emission amount of the LED 501, and therefore, in the second embodiment, the configuration related to the control of the light emission amount of the LED 501. The explanation will be focused on.

  As illustrated in FIG. 11, the image reading apparatus 300 </ b> A according to the second embodiment is different from the image reading apparatus 300 according to the first embodiment in that the control unit 410 replaces the first light emission amount control unit 411 with a light emission amount control unit. The second light emission amount control unit 412 is provided. Further, the image reading apparatus 300A of the second embodiment does not include the transparency sensor 440 and the glossiness sensor 450 as the first document state detection unit, but includes the CCD 358 as the second document state detection unit.

  The second light emission amount control unit 412 controls the light emission amounts of the plurality of LEDs 501 based on the state of the original G located at the original reading position R. Specifically, the second light emission amount control unit 412 controls the light emission amounts of the plurality of LEDs 501 based on the state of the original G detected by the CCD 358.

  As described in detail in the description of the first embodiment, the CCD 358 is originally arranged at the image forming position of the image forming lens 357, and reads an image of the document G based on the image formed by the image forming lens 357. It functions as a sensor. In the second embodiment, the CCD 358 is used as a second document state detection unit that detects the state of the document G located at the document reading position R. As will be described later, the CCD 358 detects “the reading density of the document read first” as the state of the document G.

  The CCD 358 is a so-called 4-line type CCD image sensor. More specifically, as shown in FIG. 12 and FIG. 13, the CCD 358 includes R component line sensors 358R and G (green) components for reading the R (red) component in order from the upper side to the lower side in the vertical direction Z. 4 of the G component line sensor 358G for reading, the B component line sensor 358B for reading the B (blue) component, and the monochrome line sensor (first line type image sensor) 358K for reading the original image as monochrome. A line sensor is provided. Each of the line sensors 358R, 358G, 358B, and 358K is along the main scanning direction Y. The three line sensors of the R component line sensor 358R, the G component line sensor 358G, and the B component line sensor 358B are collectively referred to as a “color line sensor 358C”.

The R component line sensor 358R includes a color separation filter that transmits the R component. The G component line sensor 358G includes a color separation filter that transmits the G component. The B component line sensor 358B includes a color separation filter that transmits the B component. The monochrome line sensor 358K does not have a color separation filter.
The color line sensor 358C is used when reading an image of a document as a color image. The monochrome line sensor 358K is used when reading an image of a document as a monochrome image. The monochrome line sensor 358K and the color line sensor 358C are alternatively used.

  As shown in FIG. 13, at the document reading position R, the reading positions corresponding to the monochrome line sensor 358K, the B component line sensor 358B, the G component line sensor 358G, and the R component line sensor 358R are in the sub-scanning direction. Deviation in X (conveyance direction). More specifically, the position where the reflected light HK corresponding to the monochrome line sensor 358K reflects, the position where the reflected light HB corresponding to the B component line sensor 358B reflects, and the reflected light HG corresponding to the G component line sensor 358G The positions where the reflected light and the reflected light HR corresponding to the R component line sensor 358R are reflected are arranged from the upstream side to the downstream side in the sub-scanning direction X, respectively.

  Accordingly, among the four line sensors 358K, 358B, 358G, and 358R, the reflected light HK is received at the earliest timing by the monochrome line sensor 358K. Thereafter, the reflected light beams HB, HG, and HR are received in the order of the B component line sensor 358B, the G component line sensor 358G, and the R component line sensor 358R. The second embodiment uses such a deviation (time lag) in the timing of receiving reflected light to detect and detect unevenness in the reading density of the original G based on the reflected light HK received by the monochrome line sensor 358K. Based on the read density unevenness, the light emission amount of the LED 501 is controlled so that the read density unevenness in the image read by the color line sensor 358C is reduced.

  Next, a control flow of the light emission amounts of the plurality of LEDs 501 by the second light emission amount control unit 412 in the second embodiment will be described with reference to FIG. FIG. 14 is a flowchart illustrating the operation of the image reading apparatus 300 according to the second embodiment.

  As shown in FIG. 14, in step ST <b> 21, the operation of conveying the original G in the original conveying unit 70 is started, and the original G placed on the original placing unit 71 is conveyed toward the original reading position R.

  In step ST22, the monochrome line sensor 358K reads the monochrome image of the document G based on the reflected light HK corresponding to the monochrome line sensor 358K.

  In step ST23, the second light emission amount control unit 412 detects unevenness in the reading density of the original G based on the monochrome image read by the monochrome line sensor 358K.

  In step ST <b> 24, the second light emission amount control unit 412 refers to the light emission amount control pattern storage unit 421 of the memory 420 and determines a light emission amount control pattern corresponding to the detected reading density unevenness of the document G.

  In step ST25, the second light emission amount control unit 412 controls the light emission amount of the LED 501 based on the determined light emission amount control pattern.

  In step ST26, based on the reflected light HR, HG, HB corresponding to the color line sensor 358C among the reflected light from the LED unit 500 (illumination unit 340) in which the light emission amount of the LED 501 is controlled, the color line sensor 358C. The image of the original G is read.

According to the second embodiment, for example, the following effects are exhibited.
The image reading apparatus 300A of the second embodiment further includes a second light emission amount control unit 412 that controls the light emission amounts of the plurality of LEDs 501 based on the state of the document G located at the document reading position R. Therefore, according to the image reading apparatus 300A of the second embodiment, the light emission amounts of the plurality of LEDs 501 are set by the second light emission amount control unit 412 based on the state of the document G when the document G is positioned at the document reading position R. Each can be controlled. Therefore, the reading density of the original G can be reduced with high accuracy.

  The image reading apparatus 300A of the second embodiment uses a CCD 358 as a second document state detection unit that detects the state of the document G located at the document reading position R, and the second light emission amount control unit 412 includes The light emission amounts of the plurality of LEDs 501 are controlled based on the state of the original G detected by the CCD 358. Therefore, according to the image reading apparatus 300A of the second embodiment, the reading density of the original G can be reduced with high accuracy without newly providing a sensor for detecting the state of the original.

  In the image reading apparatus 300 </ b> A of the second embodiment, the second document state detection unit is configured by a monochrome line sensor 358 </ b> K that receives light earliest among a plurality of lines of line-type image sensors constituting the CCD 358. Since the monochrome line sensor 358K has higher sensitivity than the color line sensor 358C, the monochrome line sensor 358K is preferably used as the second document state detection unit. In the case of an image reading apparatus including a CCD 358 composed of a 4-line image sensor, the light emission amount of the LED 501 can be controlled using the monochrome line sensor 358K that is originally provided.

  As described above, the first embodiment and the second embodiment have been described as preferred embodiments, but the present invention is not limited to the above-described embodiments and can be implemented in various forms. For example, in the present embodiment, the color copying machine 1 is described as the image forming apparatus, but the present invention is not limited to this, and may be a monochrome copying machine, a printer, a facsimile machine, or a multifunction machine thereof.

The state of the document that is a parameter for determining the control pattern of the light emission amount of the LED 501 is not particularly limited. For example, any one of the thickness of the document, the glossiness of the document, or the reading density of the document that has been read first. One or more. Furthermore, the state of the document can include the dimensions of the document.
The light emitting member in the light emitting unit is not limited to the LED 501 and may be other point light emitting members.

  In the first and second embodiments, the image reading apparatuses 300 and 300A are formed integrally with the apparatus main body M. However, the present invention is not limited to this, and the image reading apparatuses 300 and 300A are configured by a separate casing from the apparatus main body M. May be. For example, the image reading apparatus 300 may be configured to be detachable from the apparatus main body M.

  DESCRIPTION OF SYMBOLS 1 ... Color copier (image forming apparatus), 2a, 2b, 2c, 2d ... Photosensitive drum (image carrier), 7 ... Intermediate transfer belt (transfer part), 8 ... Secondary transfer roller 8 ( Transfer section), 9... Fixing section, 16a, 16b, 16c, 16d... Developer, 37a, 37b, 37c, 37d... Primary transfer roller (transfer section), 70. …… Image reading device 301 ...... Reading unit 321, 322 323 Mirror, 340 illuminating unit 357 Imaging lens 358 CCD (image sensor, second document state detecting unit) 411... First light emission amount control unit (light emission amount control unit), 412... Second light emission amount control unit (light emission amount control unit), 358 K... Monochrome line sensor (first line type image sensor), 430. ... Original state setting section, 440 ... Transparent Degree sensor (first document state detection unit), 450... Glossiness sensor (first document state detection unit), 500... LED unit (light emitting unit), 501... LED (light emitting member), G. H: Luminous flux, optical path, R: Document reading position, X: Sub scanning direction, Y: Main scanning direction, Z: Vertical direction

Claims (9)

A document transport section for transporting a document to a predetermined document reading position;
A first document state detection unit that detects a state of the document transported to the document reading position by the document transport unit;
A plurality of light emitting members that emit light to irradiate the original located at the original reading position are arranged at predetermined intervals in the main scanning direction, and a light emitting unit configured to be able to change the light emission amounts of the plurality of light emitting members, respectively. When,
A light emission amount control unit for controlling the light emission amounts of the plurality of light emitting members based on the document state detected by the first document state detection unit;
One or more mirrors that reflect the light flux from the original to form an optical path;
An imaging lens that forms an image of the light beam reflected by the one or more mirrors;
An image sensor that is disposed at an imaging position of the imaging lens and reads an image of the document based on imaging by the imaging lens;
An image reading apparatus comprising: The document conveyance unit includes a transparency sensor that detects the transparency of the document conveyed to the document reading position.
The image reading apparatus according to claim 1, wherein the first document state detection unit includes the transparency sensor. The document transport unit includes a gloss sensor for detecting the gloss level of a document transported to the document reading position,
The image reading apparatus according to claim 1, wherein the first document state detection unit includes the glossiness sensor. A document state setting unit configured to set a state of the document before the document conveyance unit starts conveying the document;
4. The image reading apparatus according to claim 1, wherein the light emission amount control unit controls the light emission amounts of the plurality of light emitting members based on the document state set by the document state setting unit. 5. . A second document state detection unit that detects a state of the document located at the document reading position;
5. The image reading according to claim 1, wherein the light emission amount control unit controls the light emission amounts of the plurality of light emitting members based on the document state detected by the second document state detection unit. apparatus. The image sensor is a plurality of lines of line-type image sensors arranged in correspondence with the document conveyance direction,
6. The image reading apparatus according to claim 5, wherein the second document state detection unit includes a first line type image sensor that receives light first in a document transport direction among a plurality of lines of line type image sensors. The image reading according to any one of claims 1 to 6, wherein the state of the original is detected based on a region in the vicinity of an upstream end in the transport direction and / or a region in the vicinity of a downstream end of the original. apparatus. The image reading apparatus according to claim 1, wherein the state of the document includes a size of the document. An image reading apparatus according to any one of claims 1 to 8,
An image carrier on which an electrostatic latent image is formed on the surface based on image information relating to an image of the original read by the image reading device;
A developing device for developing a toner image on the electrostatic latent image formed on the image carrier;
A transfer unit that directly or indirectly transfers a toner image formed on the image carrier to a predetermined sheet;
An image forming apparatus comprising: a fixing unit that fixes the toner image transferred to the predetermined sheet by the transfer unit.

Images