JP3771148B2 - Double-sided image reader - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a double-sided image reading apparatus that simultaneously reads images on both sides of one surface and the other surface of a document.
[0002]
[Prior art]
In a conventional image reading apparatus, when a document having images on both sides is read, the document is read one side at a time by automatically turning the document over by an automatic reversing mechanism for automatically inverting the document. In such an image reading apparatus, since the image is read one side at a time, the operation is troublesome, and the original cannot be read at a high speed.
[0003]
In view of such a problem, a double-sided image reading apparatus that reads images on both sides without turning over the original by arranging reading means for reading images on both sides of the original is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-254857. Yes.
[0004]
In a double-sided image reading apparatus having a function of reading both sides of a document, reading means are arranged on both sides of the document transport path. The reading unit includes a light source for irradiating the surface of the document facing each reading unit, and a photoelectric conversion unit for receiving the light reflected from the document surface by the light from the light source.
[0005]
However, light from a light source of a reading unit (hereinafter referred to as one side reading unit) that reads one surface of the document passes through the document with a light amount difference corresponding to an image on the document surface facing the reading unit. Then, the light is received by the photoelectric conversion means of the reading means for reading the other surface of the original (hereinafter referred to as the reading means on the other side). For this reason, the photoelectric conversion means of the other reading means includes image information of the original surface facing the one reading means in addition to the reflected light from the original surface to be read facing the other reading means. There was a problem that so-called show-through occurred.
[0006]
Further, since the light from the light source of the one side reading unit is incident on the other side reading unit, the reading on the other side where the reading has been completed in advance is completed even though the reading on the one side is not completed. When the light source of the reading unit is turned off, the read image data on the other side is displaced by the amount of change in the amount of light from the already read portion of the same document. Therefore, there has been a problem that the read image data changes at the place where the amount of light changes.
[0007]
In addition, whether or not there is a running document in the optical path leading to the photoelectric conversion unit of the other reading unit, that is, when light from the light source of one reading unit is blocked by the document or not. There is a problem that the amount of light received by the photoelectric conversion means of the other reading means changes, and the read image data changes at the place where the amount of light changes.
[0008]
The above-described show-through and the influence on the other side reading means due to the change in the amount of light from the other side light source during reading by the one side reading means have been particularly problematic for thin documents.
[0009]
As described above, when the light from one reading unit is received by the photoelectric conversion unit of the other reading unit, the data read by the photoelectric conversion unit of the other reading unit is affected. There is. This problem is referred to herein as optical interference.
[0010]
In view of the above problems, techniques for preventing optical interference are disclosed in, for example, Japanese Patent Application Laid-Open Nos. 9-321947, 1-198174, 3-107276, and 3-94868. It is disclosed.
[0011]
In Japanese Patent Application Laid-Open No. 9-321947, photoelectric conversion means of two reading means are arranged on both sides of a document conveying path to read both sides of a document, and the light sources of both reading means are turned on and off in units of scanning lines. By alternately controlling the reading of one surface and the other surface of the document in conjunction with turning on and off of the light source, transmitted light and show-through by the light source on the opposite side are prevented.
[0012]
In Japanese Patent Laid-Open No. 1-198174, the photoelectric conversion means of two reading means are arranged along the conveyance path of the document to read both sides of the document, and each of the two on the conveyance path read by the two photoelectric conversion means. In the area, the conveyance guide is made black and opaque to prevent show-through even in a thin document.
[0013]
In Japanese Patent Laid-Open No. 3-107276, the irradiation light of the facing light source is not transmitted between the light source of the one reading unit and the light source of the other reading unit respectively arranged on both sides of the document conveyance path. A slit is provided.
[0014]
In Japanese Utility Model Laid-Open No. 3-94869, a pair of reading means are disposed diagonally opposite to each other, and a step portion is provided in the document conveyance path by a reflecting plate that also serves as a document conveyance path therebetween, thereby preventing optical interference. Yes.
[0015]
[Problems to be solved by the invention]
However, in the technique disclosed in Japanese Patent Laid-Open No. 9-321947, the light source that irradiates the front surface of the document and the light source that irradiates the back surface of the document are repeatedly turned on and off for each scanning line to prevent optical interference. Therefore, there is a problem that the reading speed and resolution of the document are restricted by the response of the light source. That is, there is a response delay of a predetermined time in the time from when the light source is extinguished to the lighting state where the document is exposed to such an extent that the document can be read, and the time between the lighting state and the extinguishing state. Therefore, in order to control alternately for each scanning line and to alternately read one surface and the other surface of the document in conjunction with the turning on and off of the light source, it is possible to increase the document transport speed or When reading, there is a restriction due to the response delay of the light source.
[0016]
In Japanese Patent Laid-Open Nos. 1-198174 and 3-107276, when the reading unit is shaded, a mechanism is required such as moving the reading unit to read a reference white plate serving as a white reference. . However, when a contact image sensor with a shallow depth of focus is used as the reading means, the accuracy of the mechanism greatly affects the reading. Therefore, a method of performing shading and reading of a document with a contact image sensor fixed can be considered. In this case, a transparent conveyance guide member such as contact glass is disposed on the side opposite to the side on which the reading unit is disposed across the document conveyance path, and a shading reference white plate is disposed on the opposite side of the surface of the transparent conveyance guide member. Need to be placed. With such a configuration, light is transmitted through the transparent conveyance guide and optical interference occurs.
[0017]
In the technique disclosed in Japanese Utility Model Publication No. 3-94868, optical interference can be prevented. However, when the original is passed through the crank-shaped original conveyance path, a paper jam (jam) is likely to occur, and the original is damaged. Is big.
[0018]
An object of the present invention is to provide a double-sided image reading apparatus that is arranged with a conveyance guide interposed therebetween and can prevent optical interference of a reading unit that simultaneously reads both sides of a document.
[0019]
[Means for Solving the Problems]
  The present invention includes a first transport guide and a second transport guide that are juxtaposed along the transport direction of the document and are made of a light transmitting body,
  Having a light source,A first reading unit disposed on one side of the first conveyance guide and configured to read one surface of the document conveyed along the first conveyance guide;
  Having a light source,A double-sided image reading apparatus including a second reading unit that is disposed on the other side of the second conveyance guide and reads the other surface of the document conveyed along the second conveyance guideSoAnd
  Formed by a light absorber applied to each end face of the first conveyance guide and the second conveyance guide facing between the first conveyance guide and the second conveyance guide,Between the first transport guide and the second transport guideofThe double-sided image reading apparatus is characterized in that a light-shielding means for preventing light from passing is provided.
[0020]
According to the present invention, since the light shielding means for preventing the passage of light is disposed between the first conveyance guide and the second conveyance guide that are juxtaposed along the conveyance direction of the document and configured by the light transmitting body, the first A first reading unit that is arranged on one side of the conveyance guide and reads one surface of the document conveyed along the first conveyance guide, and is arranged on the other side of the second conveyance guide and along the second conveyance guide Light emitted when the second reading unit that reads the other surface of the conveyed document reads the document enters the first conveyance guide and the second conveyance guide, respectively. Multiple reflections at the other side, or after entering the first conveyance guide and the second conveyance guide, exiting the conveyance path for conveying the document and performing multiple reflections, and the other of the other arranged on the opposite side of the conveyance guide Do not enter the reading means . Therefore, optical interference can be prevented.
[0022]
  AlsoThe light-shielding member is a light absorber that absorbs light applied to the end surfaces of the first and second transport guides facing the first and second transport guides. By applying to the end face, the light shielding member can be easily formed. Further, since the light shielding member is formed on the end face by coating, the light shielding means can be arranged even if the gap between the first transport guide and the second transport guide is narrow.
[0023]
  The present invention also providesA first transport guide and a second transport guide that are juxtaposed along the transport direction of the document and are made of a light transmitting body;
  A first reading unit disposed on one side of the first conveyance guide and configured to read one surface of the document conveyed along the first conveyance guide;
  A double-sided image reading apparatus including a second reading unit disposed on the other side of the second conveyance guide and configured to read the other surface of the document conveyed along the second conveyance guide;
  A guide member is provided between the first conveyance guide and the second conveyance guide, prevents light from passing between the first conveyance guide and the second conveyance guide, and guides the document.It is characterized byA double-sided image reader.
[0024]
  According to the present invention,Since the guide member that guides the document and prevents passage of light is disposed between the first transport guide and the second transport guide that are juxtaposed along the transport direction of the document and configured by the light transmitting body. A first reading unit that is arranged on one side of the conveyance guide and reads one surface of the document conveyed along the first conveyance guide, and is arranged on the other side of the second conveyance guide and along the second conveyance guide Light emitted when the second reading unit that reads the other surface of the conveyed document reads the document enters the first conveyance guide and the second conveyance guide, respectively. Multiple reflections at the other side, or after entering the first conveyance guide and the second conveyance guide, exiting the conveyance path for conveying the document and performing multiple reflections, and the other of the other arranged on the opposite side of the conveyance guide Intrusion into reading means There is no. Therefore, optical interference can be prevented. AlsoEven if the first conveyance guide and the second conveyance guide are misaligned, the document is guided by the guide member, and the design is easy.
[0025]
In the invention, it is preferable that the guide member is a flexible sheet member that is adhered to an end surface of the first or second conveyance guide that faces between the first conveyance guide and the second conveyance guide to guide the document. Features.
[0026]
According to the present invention, since the flexible sheet body is bonded to the end surface of the first conveyance guide or the second conveyance guide that faces between the first conveyance guide and the second conveyance guide, the light shielding means is easily designed. it can. Further, since the light shielding means is a flexible sheet body, it is possible to prevent optical interference and bend the flexible sheet body from the bonded guide toward the other guide. Can guide the manuscript.
[0027]
The present invention also includes a transport guide that is disposed along the transport direction of the document and is made of a light transmissive body.
A first reading unit having a light source and reading one surface of a document conveyed along the conveyance guide on one side of the conveyance guide;
A double-sided image reading apparatus, comprising: a second reading unit that is disposed downstream of the first reading unit in the conveying direction and reads the other surface of the document conveyed along the conveying guide on the other side of the conveying guide. ,
The second reading means has a light source for irradiating the conveyed document and a lighting port for collecting reflected light from the document, and a lighting port for the second reading unit from the light source of the first reading unit. The double-sided image reading apparatus is characterized in that the conveyance guide on the second reading means side is inclined so that a prospective angle expected to be small.
[0028]
According to the present invention, the first reading means for reading one surface of the document conveyed along the conveyance guide on one side of the conveyance guide which is arranged along the conveyance direction of the document and is constituted by a light transmitting body. It is arranged downstream from the light source in the conveyance direction of the first reading unit, and the expected angle of the second reading unit that reads the other surface of the document conveyed along the conveyance guide is reduced. An optical interference between the two reading means is caused by inclining the conveyance guide on the second reading means side, that is, the portion where the second reading means faces and conveys the portion of the document to be read by the second reading means. Can be prevented.
[0029]
Further, the present invention is characterized in that the second reading means is inclined in accordance with the inclination of the conveyance guide.
[0030]
According to the present invention, since the second reading unit is inclined in accordance with the inclination of the conveyance guide, optical interference between the first reading unit and the second reading unit can be further prevented, and the first Since it is not necessary to incline the reading means, for example, the first reading means can be moved in parallel to read a stationary document.
[0031]
According to the present invention, the first reading unit reads an image by reducing it,
The second reading means reads an image at an equal magnification,
The first reading unit is disposed below the conveyance guide, and the second reading unit is disposed above the conveyance guide.
[0032]
According to the present invention, the first reading unit reads the image at a reduced size, and the second reading unit reads the image at the same magnification, and the first reading that reduces the image and requires a large space for the arrangement. Since the means is arranged below the conveyance guide and the second reading means for reading the image at the same magnification, which requires a small space for the arrangement, is arranged above the conveyance guide, the apparatus can be miniaturized.
[0033]
  The present invention also includes a transport guide that is disposed along the transport direction of the document and is made of a light transmissive body.
  Conveying means for conveying the document in one direction along the conveying guide;
  Having a light source,A first reading unit disposed on one side of the conveyance guide and configured to read one surface of a document conveyed along the conveyance guide;
  Having a light source,A double-sided image reading apparatus provided with a second reading unit disposed on the downstream side in the conveyance direction of the first reading unit and configured to read the other surface of the document conveyed along the conveyance guide;Because,
  Transport meansIs, Arranged between the first reading means and the second reading means in the document transport directionAnd block the lightThis is a double-sided image reading apparatus characterized by the above.
[0034]
  According to the present invention, the first reading unit that is arranged along the conveyance direction of the document and that reads one surface of the document conveyed along the conveyance guide is arranged on one side of the conveyance guide formed of the light transmitting body. And a second reading unit arranged on the downstream side of the first reading unit in the conveyance direction and reading the other surface of the document conveyed along the conveyance guide. The document is conveyed in one direction between the first reading unit and the second reading unit.And block the lightBy disposing the conveying means, it is possible to prevent optical interference in which the light from the first reading means or the second reading means is read by the other reading means. For example, if the conveying means is a roller, the original can be conveyed while being pressed against the conveying guide by the roller, and the original can be read more faithfully because the original does not float from the original guide.
[0035]
In the invention, it is preferable that the conveyance guide is divided into a region for the first reading unit and a region for the second reading unit.
The conveying means is a pair of rollers for conveying the document with the document interposed therebetween.
[0036]
According to the present invention, the conveyance guide is configured separately in two parts, an opposing part of the first reading means and an opposing part of the second reading means, and the first reading means and the second reading means, Since a pair of rollers can be disposed between the two reading means to block the light between the two reading means, optical interference that the light of one reading means is read by the other reading means can be prevented. . In addition, optical interference due to stray light transmitted through the document guide can be prevented. Further, stable conveyance is possible by conveying the document sandwiched between a pair of rollers. Further, since the document can be prevented from floating from the conveyance guide by the pair of rollers, the document can be read more faithfully.
[0037]
In the invention, it is preferable that the roller has a light absorber.
According to the present invention, since the roller has a light absorber, the light applied to the roller can be absorbed.
[0038]
In the present invention, the first reading means or the second reading means has two scanning units for moving and scanning,
The optical path of both units is arranged at a position where the roller pair does not block.
[0039]
According to the present invention, even if the first reading means or the second reading means has two scanning units that move and scan, the roller is arranged at a position that does not block the optical path of both units. As the first reading unit and the second reading unit, a reading unit using a reduction optical system that reads an image by reducing it can be used.
[0040]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic sectional view of a double-sided image reading apparatus 1 according to an embodiment of the present invention. The double-sided image reading apparatus 1 includes a lower housing 2, an upper housing 3, and a paper discharge tray 4. The upper housing 3 is disposed on the lower housing 2, and the paper discharge tray 4 is disposed on the side of the lower housing 3. The upper housing 3 is joined to the lower housing 2 by a hinge on the back side in the direction perpendicular to the paper surface of FIG. 1, and rotates upward with the hinge as a rotation fulcrum. As a result, the surface of the lower housing 3 facing the upper housing 2, that is, the upper surface can be opened from the near side in the direction perpendicular to the paper surface of FIG. 1.
[0041]
The double-sided image reading apparatus 1 can read a document by two reading methods: a stationary reading mode in which the document is read stationary and a traveling reading mode in which the document is read while being conveyed. In the traveling reading mode, the original can be read by two reading methods, a single-sided reading mode for reading one side of the original and a double-sided reading mode for reading images on both sides of the original.
[0042]
The lower housing 2 includes a first reading unit 20 that is a first reading unit that reads an image on one surface of a document, and the upper housing 3 is a second reading unit that reads an image on the other surface of the document. 2 reading section 30 is provided. In the single-sided reading mode of the stationary reading mode and the traveling reading mode, an image on one side of the document is read by the first reading unit 20 disposed inside the lower housing 2. In the double-sided reading mode of the traveling reading mode, both the first reading unit 20 arranged inside the lower housing 2 and the second reading unit 30 arranged inside the upper housing 3 are used to scan both sides of the document. Read the image. In the present embodiment, the document is read by the first reading unit 20 of the lower housing 2 in the single-sided reading mode of the traveling reading mode. Further, in the double-sided image reading apparatus 1 of the present embodiment, in the single-sided reading mode of the traveling reading mode, the original is read using the first reading unit 20 of the lower housing 2, but the second reading unit 30 of the upper housing 3. The document may be read using
[0043]
Hereinafter, a specific configuration of the double-sided image reading apparatus 1 will be described.
In addition to the first reading unit 20, the lower housing 2 includes a first contact glass 21 and a second conveyance guide that serve as a first conveyance guide that forms a conveyance path through which the document is conveyed when the document is read in the traveling reading mode. The second contact glass 22 is provided. The first contact glass 21 is a plate-like light transmissive body and is disposed on the surface of the lower housing 2 that faces the upper housing 3. When reading a document in the stationary reading mode, the document is placed on the first contact glass 21.
[0044]
The second contact glass 22 is a plate-shaped light transmission body, and is juxtaposed with the first contact glass 21 on the surface of the lower housing 2 facing the upper housing 3. The second contact glass 22 is disposed between the first contact glass 21 and the paper discharge tray 4 disposed on the side of the lower housing 2. The end of the first contact glass 21 on the second contact glass 22 side and the second contact glass 22 serve as a guide for forming a document conveyance path 37 through which the document is conveyed when the document is read in the traveling reading mode. . In the traveling reading mode, the document is conveyed in the direction from the first contact glass 21 side to the second contact glass 22 side. For this reason, the two contact glasses are arranged such that the upper surface of the first contact glass 21 is above the upper surface of the second contact glass 22 so that the document is not caught in the gap between the first contact glass 21 and the second contact glass 22. Is arranged.
[0045]
As shown in FIG. 2, the end surface facing the first contact glass 21 and the second contact glass 22 and the end surface facing the first contact glass 21 of the second contact glass 22 are prevented from passing light as shown in FIG. 2. As the light shielding means, black paints 121 and 122 which are light absorbers are applied.
[0046]
The first contact glass 21 is provided with a document reference plate 210 on the upper surface that indicates the position where the document is placed. The document reference plate 210 is disposed on the side of the first contact glass 21 on which the second contact glass 22 is juxtaposed. The document reference plate 210 includes an index indicating the size and placement direction of the document placed on the first contact glass 21. Therefore, the user can easily place the document on the first contact glass 21 according to this index.
[0047]
On the opposite side of the document reference plate 210 with the first contact glass 21 in between, a plate shape serving as a white reference for performing shading of the CCD 26 of the first reading unit 20 described later, that is, for determining the white level. A first reference white plate 211 as a member is provided.
[0048]
A surface of the second contact glass 22 opposite to the surface facing the upper housing 3 is a plate-like member that serves as a white reference for performing shading of the image sensor 82 of the second reading unit 30 described later. A second reference white plate 212 is provided. A light shielding member 213 that prevents light from passing is provided on the surface of the second reference white plate 212 opposite to the surface facing the second contact glass 22.
[0049]
The first reading unit 20 includes a first scanning unit 23, a second scanning unit 24, an imaging lens 25, and a CCD (Charge Coupled Device) 26 that is a photoelectric conversion unit that converts light into an electrical signal. The first reading unit 20 is a reading unit of a reduction optical system that reads an image of a document placed on the first contact glass 21 while reducing the image.
[0050]
Hereinafter, the configuration of the first reading unit 20 will be described in detail.
The first scanning unit 23 includes a light source 230, a first reflection mirror 231, and a frame 232 that holds these. The light source 230 includes an exposure lamp 233 including a xenon lamp and a reflector 234. The first scanning unit 23 moves along the first contact glass 21 at a constant speed V in a direction (from left to right in FIG. 1) from the side surface where the paper discharge tray 4 of the lower housing 2 is disposed to the other side surface. While moving, the image of the document placed on the first contact lens 21 is read. The light from the light source 230 is reflected by the original, passes through the slit 235 formed in the frame 232, and reaches the first reflecting mirror 231. The reflected light that has reached the first reflecting mirror 231 is guided to the second scanning unit 24.
[0051]
The second scanning unit 24 includes a second reflection mirror 240 and a third reflection mirror 241. The second scanning unit 24 follows the first scanning unit 23 and moves at a speed of V / 2. The light from the first reflection mirror 231 of the first scanning unit 23 is reflected by the second reflection mirror 240 and the third reflection mirror 241 and guided to the imaging lens 25.
[0052]
The imaging lens 25 images the light reflected by the third reflection mirror 241 of the second scanning unit 24 on the CCD 26. The CCD 26 converts light from the imaging lens 25 into an electrical image signal (hereinafter referred to as an image signal). The image signal generated by the CCD 26 is analog image data, and this image data is converted into digital image data by an image processing means (not shown) and stored in the storage means. Processing of the image signal generated by the CCD 26 will be described later.
[0053]
Note that a wire (not shown) is wound around the first scanning unit 23 and the second scanning unit 24 in order to synchronize and move these scanning units in the same direction. Each scanning unit is moved by a stepping motor (not shown) through this wire.
[0054]
The first scanning unit 23 of the first reading unit 20 is in a lower position of the document reference plate 210 (position pos1 in FIG. 1) than the position pos1 during standby that is not used for document reading. The first contact glass 21 on the paper tray 4 side is stopped at a position intermediate between the lower position (position of pos3 in FIG. 1) of one end portion of the first contact glass 21. This position is defined as a home position (position pos0 in FIG. 1). The first scanning unit 23 has a function of reading an image from a document in the running state in the traveling reading mode in addition to reading the document placed on the first contact glass 21 in the stationary reading mode. . When reading a document on the first contact glass 21, the first scanning unit 23 starts moving from the position pos0, passes through the position pos1, and is positioned below the other end of the first contact glass 21 (FIG. 1). A reciprocating motion is performed in the direction (position pos2 in the middle) in a direction that moves by a predetermined distance according to the document size detected by the document size detection means (not shown) and then returns to the position pos0. On the other hand, when reading a running document in the running reading mode, the first scanning unit 12 moves from the position pos0 to the position pos3 and reads the document while stopped at the position pos3.
[0055]
In the document conveyance path 37 on the first contact glass 21, a first reading area 15 for reading a document conveyed on the first contact glass 21 is set as shown in FIG. The first reflection mirror 231, the second reflection mirror 240, the third reflection mirror 241, the imaging lens 25, and the CCD 26 of the first reading unit 20 are arranged so that the reading optical path of the first reading unit 20 enters the first reading region 15. The positional relationship of each optical component is set. Depending on the positional relationship of each optical component, the central plane of the reading optical path that can be read by the CCD 26 via the imaging lens 25 is arranged so as to pass through the substantially center of the slit 235 formed in the frame 232 of the first scanning unit 23. The Here, the reading optical path is an elongated optical path extending beyond the maximum width of the traveling document in the direction perpendicular to the paper surface of FIG. 2, that is, in the main scanning direction. The central plane of the reading optical path is a plane formed by continuously connecting the center lines of the respective sections in the direction in which the light of the optical path moves in the optical path direction. As described above, by arranging the optical components, it is possible to prevent the problem that the original cannot be read due to the inclination of the reading optical path.
[0056]
As described above, the reading optical path of the first reading unit 20 enters the first reading region 15, and the center surface of the first reading unit 20 is substantially at the center of the slit 235 formed in the frame 232 of the first reading unit 20. The position of the first scanning unit 23 is set to a position pos3 in a state where each optical component of the first reading unit 20 is set so as to pass. The first scanning unit turns on the exposure lamp 232 at the position pos3, and the original passes through the first reading area 15 with the direct light from the exposure lamp 232 and the indirect light reflected by the reflector 234 from the exposure lamp 232 , And the image of the surface of the document facing the first reading unit 20 is read. For this reason, no other member is disposed in the vicinity of the first reading region 15 so as not to prevent the passage of light.
[0057]
A rotatable lower discharge roller 50 is integrally attached to the lower casing 2 at the end of the lower casing 2 on the sheet discharge tray 4 side. The lower discharge roller 50 is used for discharging a document in the traveling reading mode.
[0058]
Next, referring to FIG. 1 again, a detailed configuration of the upper housing 3 will be described.
In addition to the second reading unit 30, the upper housing 3 includes an OC mat 31, a document setting tray 32, an open door 33, and a document conveying unit 34. The OC mat 31 is provided on a surface of the lower housing 2 facing the first contact glass 21 and is disposed at a position where the original is pressed against the first contact glass 21 with the upper housing 3 being in close contact with the lower housing 2. Is done. The OC mat 31 is made of a white sheet that comes into contact with the document placed on the first contact glass 21 and an elastic foam such as a sponge disposed between the white sheet and the upper housing 3. Composed.
[0059]
The document set tray 32 is a table for placing a document to be read in the traveling reading mode, and is provided integrally with the exterior of the upper housing 3. In the present embodiment, since the first reading unit 20 of the lower housing 2 is used in the single-sided reading mode of the traveling reading mode, the front surface of the document is on the upper housing 3 side, that is, the lower side, and the back surface of the document is on the upper side. The original is placed on the original set tray 32.
[0060]
The open door 33 is an openable / closable door provided on the upper surface of the upper housing 3 in order to adjust the attachment of the second reading unit 30 to the upper housing 3 and the attachment state of the second reading unit 30. .
[0061]
The second reading unit 30 is a reading unit of an equal-magnification optical system that reads an original at an equal magnification, and includes an image sensor unit 35 and the like. The second reading unit 30 reads an image on the other surface of the document, that is, an image on the back surface of the document in the present embodiment, while the document placed on the document set tray 32 is being conveyed. The second reading unit 30 is located at a position downstream of the position of pos3 arranged when the first reading unit 20 of the lower housing 2 is in the document transport mode in the document transport direction in which the document is transported. It is arranged at a position above the contact glass 22. The second reading unit 30 reads the second reading area 16 of the document conveyance path 37 as shown in FIG.
[0062]
The document transport section 34 feeds a document along an upper housing upper transport guide 38A, an upper housing lower transport guide 38B, an upper housing document guide 38C, and the document transport path 37 that form a document transport path 37 for transporting the document. A document conveying means 39 for conveying is provided. The document transport unit 34 is disposed on the side where the paper discharge tray 4 is disposed, and transports the document from the document set tray 32 to the paper discharge tray 4. The document conveying means 39 takes the document placed on the document setting tray 32 into the document conveying path 37 and causes the first reading unit 20 and the second reading unit 30 to read the document while conveying the document conveying path 37. Later, the document is discharged to the discharge tray 4.
[0063]
Hereinafter, a detailed configuration of the document conveying unit 34 will be described.
FIG. 3 is an enlarged schematic cross-sectional view showing the vicinity of the document conveying section 34. The document transport unit 39 of the document transport unit 34 includes a document set detection sensor 40, a paper feed auxiliary roller 41, a document pressing plate 42, a friction pad 43, a feed roller 44, a feed timing sensor 45, an alignment roller pair 46, and a document discharge. The unit 47 is provided.
[0064]
The document set detection sensor 40 detects whether or not a document is placed on the document set tray 32.
[0065]
The auxiliary feeding roller 41 and the document holding plate 42 take the document placed on the document set tray 32 into the document transport path 37 based on the detection result of the document set detection sensor 40. The document holding plate 42 comes into contact with the auxiliary feeding roller 41 from above, and the auxiliary roller 41 rotates in the direction of the arrow A about the rotation axis extending in the direction perpendicular to the paper surface of FIG. It is nipped between the feeding roller 41 and the document holding plate 42 and conveyed.
[0066]
The friction pad 43 and the feeding roller 44 are disposed downstream of the feeding auxiliary roller 41 and the document holding plate 42 in the document feeding direction, and are taken into the document feeding path 37 by the feeding auxiliary roller 41 and the document holding plate 42. The originals are separated one by one and conveyed. The friction pad 43 is pressed against the feeding roller 44 from above, and the feeding roller 44 is driven to rotate in the direction of arrow B about a rotation axis extending in a direction perpendicular to the paper surface of FIG. The documents are separated one by one at the pressure contact portion between the feed roller 44 and the feed roller 44.
[0067]
The feeding timing sensor 45 is disposed downstream of the friction pad 43 and the feeding roller 44 in the document conveyance direction, and detects the presence or absence of a document in the document conveyance path 37 in order to measure the document reading timing.
[0068]
The alignment roller pair 46 is disposed downstream of the feeding timing sensor 45 in the document conveyance direction. The alignment roller pair 46 includes an upper alignment roller 46A disposed on the upper side and a lower alignment roller 46B disposed on the lower side of the upper alignment roller 46A and in contact with the upper alignment roller 46A. The upper alignment roller 46A rotates in the direction of the arrow C about the rotation axis extending in the direction perpendicular to the paper surface of FIG. 3, so that the lower alignment roller 46B is centered on the rotation axis extending in the direction perpendicular to the paper surface of FIG. The document is rotated in the direction of the arrow D, and the document is nipped and conveyed between the upper alignment roller 46A and the lower alignment roller 46B. Based on the detection result of the feeding timing sensor 45, the alignment roller pair 46 has an end portion in the conveyance direction of the document separated and fed by the friction pad 43 and the feeding roller 44 in the document conveyance direction. The document is conveyed by correcting the inclination of the document so that it is perpendicular to the sheet.
[0069]
The feeding auxiliary roller 41, the feeding roller 44, and the upper alignment roller 46A have an electromagnetic clutch (not shown) on their rotating shafts, and are in a stopped state in which the driving force from the driving motor (not shown) is not transmitted. And an operation state in which the driving force from the drive motor is transmitted. The feeding auxiliary roller 41 and the feeding roller 44 rotate while the electromagnetic clutch is turned on during the conveyance of the document, and stop rotating when the conveyance of the document is stopped. When there is no document on the upstream side of the alignment roller pair 46 in the conveying direction, the alignment roller pair 46 is in a state where the electromagnetic clutch is turned off and the rotation is stopped. When the leading edge of the document comes into contact with the feeding timing sensor 45, a predetermined signal is generated from this sensor. Thereafter, the leading edge of the document hits the nip portion of the alignment roller pair 46, and the document begins to bend. When a predetermined signal is issued from the feeding timing sensor 45, a timer that sets a predetermined time is started. In accordance with this timer, the electromagnetic clutch of the alignment roller pair 46 is turned on to rotate the alignment roller pair 46 and feed the document downstream in the conveyance direction. Deflection is formed in the original document from the time when the original document hits the nip portion of the alignment roller pair 46 until the timer counts a predetermined time. Due to the elastic force caused by the deflection of the original, the front end of the original is pressed to align with the upstream edge of the nip portion of the alignment roller pair 46 in the original conveying direction. The alignment roller pair 46 is attached to the upper casing 2 in advance so that the upstream edge of the nip portion of the alignment roller pair 46 is parallel to the direction perpendicular to the conveyance direction of the document conveyance path 37. In this way, the alignment roller pair 46 corrects the inclination of the document with respect to the document conveyance direction.
[0070]
The document discharge unit 47 includes an upper discharge roller 48 and a document discharge sensor 49. The upper discharge roller 48 is provided at one end of the upper housing 3 where the paper discharge tray 4 is disposed, and is provided integrally with the upper housing 3 and is driven by a drive mechanism disposed inside the upper housing 3. It is driven to rotate in the direction of arrow E around a rotation axis extending in a direction perpendicular to the paper surface of FIG. The upper discharge roller 48 is in contact with the lower discharge roller 50 of the lower casing 2 in a state where the lower casing 2 and the upper casing 3 are in close contact with each other, and sandwiches and conveys the document together with the lower discharge roller 50 that is a driven roller. . The document discharge sensor 49 is disposed on the downstream side of the upper discharge roller 48 in the document transport direction, and transmits a discharge completion signal to a control unit to be described later when the document is discharged to the paper tray.
[0071]
The document transport path 37 passes through a contact portion between the feeding auxiliary roller 41 and the document pressing plate 42, a pressure contact portion between the friction pad 43 and the feeding roller 44, and a nip portion between the alignment roller pair 46, and an upper discharge roller 49 and a lower discharge roller. It extends to reach 50 nips. In order to define the document conveyance path 37 to a predetermined gap, an upper casing is disposed above the document conveyance path 37 between the contact portion of the feeding auxiliary roller 41 and the document pressing plate 42 and the nip portion of the alignment roller pair 46. An upper conveyance guide 38A is formed, and an upper casing lower conveyance guide 38B is formed below the document conveyance path 37. Further, an upper casing document guide 38C is formed integrally with the upper casing 3 on the upper side of the document conveying path 37 from the downstream side of the alignment roller pair 46 in the document conveying direction to the upper discharge roller 48. In the upper housing 3, the space between the upper document guide 38 </ b> C and the upper discharge roller 48 is integrally formed on the wall surface of the upper housing. The upper casing document guide 38 </ b> C is a lower casing from the first contact glass (first transport guide) 21 and the second contact glass (second transport guide) 22 of the lower casing 2 to the lower discharge roller 50. A document conveyance path 37 is formed together with a guide integrally formed on the upper surface of the body 2. Black paint is applied to the surface of the upper casing document guide 38C on the document conveyance path 37 side.
[0072]
The feeding timing sensor 45 described above includes a detection piece 45a that is angularly displaced with the one end portion as a fulcrum. The detection piece 45a is configured to protrude from an opening provided in the upper casing upper conveyance guide 38A and reach an opening provided in the upper casing lower conveyance guide 38B. When the leading edge of the document presses the detection piece 45a, the light between the photointerrupters disposed in the main body of the feeding timing sensor 45 disposed on the side opposite to the document transport side of the upper casing upper transport guide 38A. The feeding timing sensor 45 detects the arrival of the document.
[0073]
  In the document transport path 37, the portion between the pressure contact portion between the friction pad 43 and the feeding roller 44 and the nip portion of the alignment roller pair 46, and a predetermined distance away from the alignment roller 46 downstream in the document transport direction. The partial document conveyance path 37 is formed on the upper surface of the upper housing 3.ThisIn order to convey the original on the original set tray 32 to the upper surface of the lower housing 2, the original is inclined downward and formed in a substantially linear shape. Further, the document conveying path 37 extends from the downstream end portion of the inclined portion of the document conveying path 37 to the nip portion of the upper discharge roller 48 and the lower discharge roller 50 in a substantially horizontal direction. Yes.
[0074]
The upper housing document guide 38 </ b> C includes a third contact glass 60 that is a light transmitting member at a position facing the second contact glass 22 of the lower housing 2. The position of the upper housing document guide 38C with respect to the second contact glass 22 is set by a plurality of positioning projections 61 projecting from the upper housing document guide 38C toward the document conveyance path 37 side. The third contact glass 60 is adhered to a recess formed on the document transport path 37 side of the upper housing document guide 38C with an adhesive. The third contact glass 60 is arranged such that the surface of the upper housing document guide 38C on the document conveyance path 37 side and the surface of the third contact glass 60 facing the second contact glass 22 are substantially horizontal. The second reading unit 30 is disposed on the opposite side of the third contact glass 60 from the document conveyance path 37. The third contact glass 60 realizes light transmission between the second reading unit 30 and the original and prevents jamming of the original.
[0075]
Next, the configuration of the second reading unit 30 will be described in detail with reference to FIG. The second reading unit 30 includes an image sensor unit 35, a unit fixing plate 65, and a unit holding plate 66. The image sensor unit 35 is disposed on the third contact glass 60 provided in the upper housing document guide 38C. The image sensor unit 35 is suspended via a unit fixing plate 65 and a unit holding substrate 66 from an attachment reference plate 67 that extends in a direction perpendicular to the document conveyance direction and is fixed to the upper housing 3. Installed.
[0076]
FIG. 4 is a perspective sectional view showing an installation configuration of the image sensor unit 35. The attachment reference plate 67 has an opening 68 at the center. Both ends of the opening 68 in the document conveying direction are provided upward, and a bend-raised portion 70 extending in an L shape from the end of the portion erected above the opening 68 toward the outside of the opening 68 is provided. ing. A plate-like unit fixing plate 65 is passed to the bending raising portions 70 arranged side by side in the document conveying direction, and this unit fixing plate 65 is fixed by an image sensor unit fixing screw 71.
[0077]
The unit holding plate 66 is a hollow quadrangular prism-shaped member, and is fixed to the unit holding plate 66 from above with an image sensor unit adjusting screw 72 with the unit fixing plate 65 inserted therethrough. The image sensor unit 35 is firmly fixed to the unit holding plate 66. Further, the height position and posture of the unit fixing plate 65 with respect to the mounting reference plate 67 can be shifted within a predetermined range by adjusting a plurality of image sensor unit fixing screws 71 and image sensor unit adjusting screws 72. . That is, the position of the image sensor unit 35 and the height position, which is a relative distance from the third contact glass 60, are controlled in minute units by adjusting the image sensor unit fixing screw 71 and the image sensor unit adjustment screw 72. it can. Accordingly, it becomes easy to strictly arrange the image sensor unit 35 in the optimum posture and the optimum position.
[0078]
As shown in FIG. 4, the upper housing document guide 38 </ b> C is fixed to both ends of the attachment reference plate 67 in the direction perpendicular to the document conveyance direction by stepped screws 72 and guide biasing springs 73. As a result, the height of the document conveyance path 37, that is, the distance between the upper housing document guide 38C and the first contact glass 21 and the second contact glass 22 is always constant even if there is a difference in the accuracy of each component. can do.
[0079]
Further, the adjustment of the image sensor unit fixing screw 71 and the image sensor unit adjustment screw 72 described above can be performed from above the upper housing 3 by opening the opening door 33 as shown in FIG. Furthermore, the second reading unit 30 is configured to be detachable by opening the open door 33 as shown in FIG.
[0080]
Next, a detailed configuration of the image sensor unit 35 of the second reading unit 30 will be described. The image sensor unit 35 generates an LED (Light Emitting Diode) array 80 that is a light source for irradiating a document therein, a rod-shaped lens array 81 that collects reflected light from the document, and an image signal corresponding to the intensity of received light. A surface facing the image sensor 82 and the document conveyance path 37 is provided with a lighting port 95 for irradiating the document from the LED array 80 and collecting reflected light from the document. The image sensor 82 is a contact type photoelectric conversion element (CIS: Contact Image Sensor). The focus of the rod-shaped lens array 81 is slightly closer to the second contact glass 22 than the center of the height of the document conveyance path 37, that is, the center of the gap between the upper housing 3 and the second contact glass 22. Is set to Accordingly, the depth of field of the rod-shaped lens array 81 occupies most of the height of the document conveyance path 37 from the surface of the second contact glass 22. Therefore, the reflected light from the second reference white plate 212 received by the image sensor 82 is absorbed by the second contact glass 22 when the light travels back and forth through the thickness of the second contact lens 22, and has a rod shape. When the focal length of the lens array is deviated, the reflected light from the white portion of the document passing through the document transport path 33 is lowered. This decrease in reflected light is corrected with reference to a predetermined correction value stored in the look-up table for the reading value of the second reference white plate 212 to determine the white level. Further, the daylighting port 95 of the image sensor unit 35 may be simply opened. However, in the present embodiment, by installing a light transmitting body in the daylighting port 95, dust or the like is introduced into the image sensor unit 35. Prevents intrusion.
[0081]
Next, the reading process of the double-sided image reading apparatus 1 will be described with reference to FIG.
In the stationary reading mode, the document is read using only the first reading unit 20 of the lower housing 2. The first scanning unit 23 of the first reading unit 20 is first arranged at the position pos0. Then, in accordance with an instruction from the control means, the original placed on the first contact glass 21 is moved from the position pos1 to the position pos2 together with the second scanning unit 24 while scanning. As a result, the CCD 26 can receive the reflected light corresponding to the image of the document. As described above, the first reading unit 20 reads an image formed on the lower surface of the document placed on the first contact glass 21.
[0082]
On the other hand, in the traveling reading mode, it is possible to select a single-sided reading mode for reading one side of a document and a double-sided reading mode for reading both sides of a document. In the single-sided reading mode of the both-side reading mode, only the first reading unit 20 is used for reading a document. When instructed in this mode, the first scanning unit 23 of the first reading unit 20 moves from the position pos0 to the position pos3 and stops, and keeps the stopped state as it is, so that the document transporting of the upper housing 3 is performed. The original conveyed by means 39 is read. Then, in response to an instruction from the control means, the CCD 26 reads the document from the lower side via the first contact glass 21. That is, the first reading unit 20 reads an image formed on the lower side of the document, that is, an image formed on the front side in the present embodiment.
[0083]
In the double-sided reading mode of the traveling reading mode, both the first reading unit 20 and the second reading unit 30 are used for reading a document. At this time, the first scanning unit 23 of the first reading unit 20 stops at a position of pos3 below the end of the first contact glass 21 as in the single-sided reading mode of the traveling reading mode. Then, in response to an instruction from the control means, the first reading unit 20 reads an image of the document conveyed through the first contact glass 21 from the lower side. Further, the second reading unit 30 reads an image formed on the upper surface of the original conveyed via the third contact glass 60, in this embodiment, the back surface. Thus, in the double-sided reading mode, the first reading unit 20 and the second reading unit 30 simultaneously read the image of the conveyed document from the up and down direction.
[0084]
The first reading unit 20 and the second reading unit 30 irradiate the document with light when reading the image. The end surface of the first contact glass 21 facing the second contact glass 22 and the second contact glass 22 Since the black paints 121 and 122 are respectively applied to the end faces facing the one contact glass 21, the light of one reading unit enters from the end faces of the first contact glass 21 and the second contact glass 22, It is possible to prevent multiple reflections from entering and interfering with the other reading unit. Further, in this embodiment, since the optical interference can be prevented only by applying the black paints 121 and 122 to the end faces of the first contact glass 21 and the second contact glass 22, the configuration of the apparatus is easy. In addition, light shielding is possible even with a small gap. Further, since the light shielding means is formed integrally with the conveyance guide, assembly is easy and the number of parts of the apparatus can be reduced.
[0085]
As described above, in the double-sided image reading apparatus 1, the first reading unit 20 and the second reading unit 30 are arranged with the document interposed therebetween, and read both the front and back sides of the conveyed document at a time. Therefore, compared with an image reading apparatus configured to read an image on one surface with one reading unit and then reversely read the original to read an image on the other surface, the original can be read more quickly.
[0086]
Further, since both sides of the original can be read only by conveying the original by the original conveying means 39 formed in the upper housing 3, the structure of the apparatus can be simplified. Furthermore, since only one alignment means for correcting the inclination of the document needs to be provided, the conveyance control is facilitated. Therefore, even if the user uses only the stationary reading mode and uses the traveling reading mode and the duplex reading mode less frequently, the apparatus configuration does not increase. Further, the problem that the apparatus configuration becomes complicated and the cost becomes high can be solved.
[0087]
Further, in the double-sided image reading apparatus 1, the second reading unit 30 can be attached and detached from the upper side of the portion where the constituent members of the document conveying unit 34 are few by opening the open door 33 provided on the upper portion of the upper housing 3. it can. Therefore, the design degree of a structural member can be raised.
[0088]
In addition, since the height position and orientation of the image sensor unit 35 of the second reading unit 30 can be easily adjusted with respect to the document conveyance path 37, the position shift of the image sensor unit 35 that causes image degradation can be prevented. It can be easily solved.
[0089]
Further, the height position and posture of the upper casing document guide 38C can be easily adjusted, and the document transport path 37 can be configured at an optimum height, so that jamming of the document can be prevented.
[0090]
In addition, a first reading unit 20 that reads a document that requires a large installation space in a reduced manner is disposed below the first contact glass 21 serving as the first conveyance guide in the lower housing 2, and is disposed above the second contact glass 22. By disposing the second reading unit 30 that reads an original that may have a small installation space at an equal magnification on the upper housing document guide 38C, the apparatus can be reduced in size.
[0091]
FIG. 6 is a block diagram showing an electrical configuration of the double-sided image reading apparatus 1 described above. The double-sided image reading apparatus 1 includes a control unit that controls the apparatus and an image processing unit that processes an image signal read from a document, in addition to the above-described units.
[0092]
The control means includes a system controller 100, a communication control part 101, a reading control part 102, a system bus 103, a first light source control board 106, a first reading part drive motor control board 108, a second light source control board 107, and a document conveying means drive. A motor control board 111 and an operation unit 115 are provided.
[0093]
The image processing means includes image processing units 120 and 130, an image processing relay unit 104, an image memory 105, and the like.
[0094]
The system controller 100 controls the reading control unit 102 via the communication control unit 101 and further controls the image processing relay unit 104 and the image memory 105 via the system bus 103. Thus, the system controller 100 controls the entire apparatus so that the document reading operation is appropriately performed.
[0095]
The first light source substrate 106 turns on or off the exposure lamp 233 of the light source 230 of the first reading unit 20 based on a signal from the reading control unit 102. The second light source substrate 107 turns on or off the LED array 80 of the second reading unit 30 based on a signal from the reading control unit 102.
[0096]
The first reading unit driving motor control board 108 controls the first reading unit driving motor 109 based on the signal from the reading control unit 102 to move the first scanning unit 23 and the second scanning unit 24.
[0097]
The first reading unit position sensor group 110 outputs a reference position signal to the reading control unit 102 when the first scanning unit 23 is disposed at positions pos0, pos1, pos3, and pos4.
[0098]
The reading control unit 102 calculates the position of the first scanning unit 23 on the basis of the reference position signal of the first reading unit position sensor group 110 and the number of steps of the first reading unit driving motor 109, and the first reading unit The control motor 109 is controlled in forward and reverse directions to reciprocate the first scanning unit 23 and the second scanning unit 24.
[0099]
The drive motor control board 111 controls on / off of the stepping motor, which is the drive motor 112, according to a signal from the reading control unit 102, and drives the document conveying means 39 to feed the auxiliary paper feed roller 41, the paper feed roller 44, and the upper alignment roller 46A. The driving force is transmitted to the upper discharge roller 48. Further, the rotation speed of the drive motor 112 can be changed by a pulse rate from the drive motor control board 111.
[0100]
A document detection sensor group 113, which is a document set detection sensor 40, a paper feed timing sensor 45 and a document discharge sensor 49, transmits a signal to the reading control unit 102 when the document reaches the sensor position. On the other hand, the reading control unit 102 calculates whether or not the document is conveyed at an appropriate timing by using a signal from the document set detection sensor 40, the paper feed timing sensor 45, and the document discharge sensor 49 and a timer. If it is determined that the conveyance is not appropriate, a signal such as a jam indicating that the original is jammed in the conveyance path is transmitted to the system controller 102 via the system bus 103.
[0101]
The electromagnetic clutch group 114 is turned on / off in response to a signal from the reading control unit 102 and is switched between connection and disconnection with respect to each drive system of the document conveying unit 39 to stop or rotate the drive system.
[0102]
The operation unit 115 is a unit that allows the user to give various instructions to the double-sided image reading apparatus 1 and includes operation keys. For example, when reading a document in the traveling reading mode, the single-sided reading mode or the double-sided reading mode is selected. can do.
[0103]
Next, processing of an image signal obtained by reading scanning in the single-sided reading mode and the single-sided reading mode will be described.
[0104]
Image signals obtained by the CCD 26 and the image sensor 82 are sent to the image processing units 120 and 130, respectively, and then predetermined image processing is performed in the image processing units 120 and 130. Then, after being sent to the image processing relay unit 104 and further subjected to predetermined image processing, it is distinguished for each page via the system bus 103 and stored in the image memory 105 as storage means. The image processing units 120 and 130 include analog signal processing units 121 and 131, A / D conversion units 122 and 132, shading correction units 123 and 133, filter processing units 124 and 134, and density conversion units 125 and 135, respectively. Yes.
[0105]
The analog signal processing units 121 and 131 perform level conversion processing, sample hold processing, and signal amplification processing on the image signals input from the CCD 26 and the image sensor 82 and output the result to the A / D conversion units 122 and 132. Since the CCD 26 and the image sensor 82 differ in the amount of light from the light source, the photoelectric conversion efficiency, the output signal level, and the like, dedicated analog signal processing units 121 and 131 are provided for the CCD 26 and the image sensor 82, respectively.
[0106]
The A / D conversion units 122 and 132 digitally convert the analog image signals input from the analog signal processing units 121 and 131 and output the quantized image signals to the shading correction units 123 and 133.
[0107]
The shading correction units 123 and 133 perform black reproduction and white reproduction on the quantized image signals input from the A / D conversion units 122 and 132 and output the result to the filter processing units 124 and 134. Here, the black reproduction means the influence of the implied output by sampling and storing the implied output of the CCD 26 or the image sensor 82 and subtracting it from the image signal output from the CCD 26 or the image sensor 82 at the time of reading the document as read data. Is to reduce. In the white reproduction, the image signal at the time of reading the original is normalized to each pixel based on the image signal for each pixel when the reference white plate having a uniform reflectance is read, and the CCD 26 And the variation in sensitivity of the image sensor 82 is corrected.
[0108]
The filter processing units 124 and 134 perform predetermined filter processing on the image signals input from the shading correction units 123 and 133 based on coefficients that determine the filter characteristics set by the reading control unit 104. Specifically, by applying a spatial filtering process, the high frequency component of the image is emphasized and the blur of the image is repaired. That is, the image signals output from the CCD 26 and the image sensor 82 include optical components such as lenses and mirrors, aperture apertures of the light receiving surfaces of the CCD 26 and the image sensor 82, transfer efficiency and afterimages of the CCD 26 and the image sensor 82, physical There is degradation in MTF (Modulation Transfer Function) due to integration effects due to scanning and scanning unevenness, and the MTF degradation is compensated for by the filter processing unit.
[0109]
Since the degree of deterioration of the MTF differs greatly between the CCD 26 and the image sensor 82, an appropriate filter processing unit is also provided for each, and the filter processing is performed. Further, since the degradation of the MTF is more remarkable in the high frequency region, the filter processing unit performs image edge enhancement processing on the image signal in the high frequency region, thereby repairing the blur and improving the image quality. ing.
[0110]
The density conversion processing units 125 and 135 perform density conversion on the image signals filtered by the filter processing units 124 and 134. For example, when an image signal is transmitted by facsimile or when printing is performed with a printing apparatus in which the printing condition is specified to be binarized, the image signal is binarized and the printing condition is multivalued such as a photographic image. In the case of an image signal, the image quality is improved by performing density conversion using predetermined density characteristics.
[0111]
The density conversion units 125 and 135 include a RAM control unit, a RAM, and the like, and read the data conversion lookup table set in the RAM as an address of the input image signal to perform data conversion and perform density conversion processing. The image signal for which the density conversion process has been completed is stored in the image memory.
[0112]
As described above, in the double-sided image reading apparatus 1 of the present invention, the first contact glass 21 that is the first transport guide and the light that passes through the second contact glass 22 that is the second transport guide and the second contact glass 22 are obstructed. Interference can be prevented and the original can be read satisfactorily.
[0113]
Further, in the double-sided image reading apparatus 1, light is shielded by applying black paint 121, 122 to the end face that faces between the first contact glass 21 and the second contact glass 22, but as shown in FIG. A configuration may be adopted in which a guide member 90 that prevents passage of light and guides a document is disposed between the contact glass 21 and the second contact glass 22. The surface of the guide member 90 on the side of the document conveyance path 37 is substantially parallel to the top surfaces of the first contact glass 21 and the second contact glass 22 and guides the document conveyed through the document conveyance path 37.
[0114]
In this way, by blocking light between the first contact glass 21 and the second contact glass 22 by the guide member 90, optical interference can be prevented and the first contact glass 21 and the second contact glass 22 can be prevented. Even if the surface on the side of the document conveyance path 37 is slightly deviated, it can be adjusted by arranging the guide member 90, so that the design becomes easy.
[0115]
Further, the surface of the guide member 90 on the side of the document conveyance path 37 is inclined upward from the first contact glass 21 toward the second contact glass 22 side, and the end of the guide member 90 on the first contact glass 21 side is the first. The position may be lower than the upper surface of the contact glass 21 and the end of the guide member 90 on the second contact glass 22 side may be higher than the upper surface of the second contact glass 22. By doing so, it is possible to prevent jamming of the conveyed document.
[0116]
Further, in the double-sided image reading apparatus 1, light is shielded by applying black paint 121, 122 to the end face that faces between the first contact glass 21 and the second contact glass 22, but as shown in FIG. A configuration may be adopted in which a flexible sheet body 91 that is bonded to the end surface of the contact glass 21 facing the second contact glass 22 and bends along the document conveyance path 37 to the second contact glass 22 side is shielded from light.
[0117]
As described above, the light between the first contact glass 21 and the second contact glass 22 is shielded by the flexible sheet 91, thereby preventing optical interference. Further, since the flexible sheet 91 is a sheet-like member, it can be disposed even if the gap between the first contact glass 21 and the second contact glass 22 is narrow. Further, the flexible sheet body 91 is bent along the document conveyance path 37 from the conveyance guide on the side to be bonded as shown in FIG. 8, so that the gap between the first contact glass 21 and the second contact glass 22 is obtained. It becomes a guide member for guiding the document. Alternatively, the flexible sheet 91 may be bonded to the end surface of the second contact glass 22 facing the first contact glass 21 and bend along the document conveyance path 37 to the first contact glass 21 side.
[0118]
FIG. 9 is a schematic cross-sectional view of a double-sided image reading apparatus 5 according to another embodiment of the present invention, and FIG. 10 is an enlarged cross-sectional view of the vicinity of the document conveying portion 34 of the double-sided image reading apparatus 5. Similar to the double-sided image reading device 1 of the above-described embodiment, the double-sided image reading device 5 can read a document in the stationary reading mode and the traveling reading mode. In the double-sided image reading apparatus 5 of the present embodiment, the same members as those of the double-sided image reading apparatus 1 of the above embodiment are denoted by the same reference numerals, and description thereof is omitted. The double-sided image reading device 5 shown in FIG. 9 and the double-sided image reading device 1 shown in FIG. 1 differ only in the configuration near the second reading unit 30.
[0119]
Specifically, the second contact glass 22 and the second reading unit 30 are arranged so that the prospective angle when the lighting port 95 of the image sensor unit 35 of the second reading unit 30 is viewed from the light source 230 of the first reading unit 20 is reduced. The first contact glass 21 is inclined upward by about 10 degrees. The prospective angle in the present embodiment is a solid angle connecting this point and the opening edge of the daylighting port 95 when the daylighting port 95 of the image sensor unit 35 is viewed from an external point. When the 95 is viewed from the front, the prospective angle becomes the maximum.
[0120]
With this configuration, light sneaking to the other reading unit of the LED array 82 that is the light source 230 of the first reading unit 20 and the light source of the second reading unit 30 can be reduced, and optical interference is prevented. can do.
[0121]
FIG. 11 is a cross-sectional view illustrating a configuration in the vicinity of the second reading unit 30 of the double-sided image reading device 5. In the document transport section 34 of the upper housing 3 of the double-sided image reading device 5, a first upper housing document guide 138 that forms a document transport path 37 along the document transport direction between the upper alignment roller 46 A and the upper discharge roller 48. A second upper casing document guide 139 is provided in order. The first upper casing document guide 138 extends from the downstream side of the upper alignment roller 46A in the document conveyance direction to the end of the first contact glass 21, and is formed by a plurality of positioning projections 61 projecting toward the document conveyance path 37 side. The gap between the two is maintained at a predetermined distance.
[0122]
The second upper casing document guide 139 extends from the downstream side of the first upper casing document guide 138 in the document transport direction to the upstream side of the upper discharge roller 48 in the document transport direction. The second upper casing document guide 139 includes a third contact glass 60 that is a light transmitting body at a position facing the second contact glass 22 of the lower casing 2. The position of the second upper housing document guide 139 with respect to the second contact glass 22 is set by a plurality of positioning projections 61 projecting from the second upper housing document guide 139 toward the document conveyance path 37. The third contact glass 60 is adhered to a recess formed on the side of the document conveyance path 37 of the second upper casing document guide 139 with an adhesive. The third contact glass 60 is disposed so that the surface of the second upper housing document guide 139 on the document conveyance path 37 side and the surface of the third contact glass 60 facing the second contact glass 22 coincide with each other. The second reading unit 30 is disposed on the opposite side of the third contact glass 60 from the document conveyance path 37. The third contact glass 60 realizes light transmission between the second reading unit 30 and the original and prevents jamming of the original.
[0123]
In the present embodiment, since the second reading unit 22 is tilted together with the second contact glass 22 and attached to the upper housing 3, the mounting reference extends in a direction perpendicular to the document conveyance direction and is fixed to the upper housing 3. The plate 67 is inclined at a predetermined angle.
[0124]
The second reading unit 30 is attached to the attachment reference plate 67 with the same configuration as the double-sided image reading device 5 of the above embodiment, and the open door 33 formed on the upper portion of the upper housing 3 as shown in FIG. It is provided to be detachable from. The second upper casing document transport guide 139 is fixed to the mounting reference plate 67 with a stepped screw and a guide biasing spring, like the upper casing document transport guide 38C of the above embodiment.
[0125]
A guide member 90 is provided between the first contact glass 21 and the second contact glass 22. As a result, the original can be smoothly transferred from the first contact glass 21 onto the second contact glass 22 inclined.
[0126]
As described above, in the double-sided image reading device 5 of the present embodiment, optical interference is prevented by curving the document conveyance path 37. However, the double-sided image reading device described in Japanese Utility Model Laid-Open No. 3-94868 is known. Thus, since it is not necessary to make the document conveyance path into a crank shape, the processing can be performed quickly and the frequency of jamming can be reduced.
[0127]
The electrical configuration of the double-sided image reading device 5 is the same as the electrical configuration of the double-sided image reading device 1 shown in FIG.
[0128]
FIG. 13 is a schematic cross-sectional view of a double-sided image reading apparatus 6 according to another embodiment of the present invention, and FIG. 14 is an enlarged cross-sectional view of the vicinity of the document conveying portion 34 of the double-sided image reading apparatus 6. Similar to the double-sided image reading device 1 of the above-described embodiment, the double-sided image reading device 6 can read a document in the stationary reading mode and the traveling reading mode. In the double-sided image reading device 6 of the present embodiment, the same members as those of the double-sided image reading device 1 of the above embodiment are denoted by the same reference numerals, and the description thereof is omitted. The double-sided image reading device 6 shown in FIG. 13 and the double-sided image reading device 1 shown in FIG. 1 are different in the configuration of the document conveying section 34, the first contact glass 21, and the second contact glass 22.
[0129]
Hereinafter, a specific configuration will be described. In the lower housing 2 of the double-sided image reading device 6 of the present embodiment, the first contact glass 21 does not form the document transport path 37, and the lower contact is discharged from the second contact glass 22 and the end of the second contact glass 22 in the document transport direction. The second contact glass 22 is arranged so that only the guide integrally formed on the upper surface of the lower housing 2 up to the roller 50 constitutes the document conveyance path 37. That is, the length of the second contact glass 22 along the document conveyance direction is formed longer than the length of the double-sided image reading device 6 of the above embodiment, and the first reading unit 20 is in the traveling reading mode for conveying the document in the second reading mode. A document is read from below the glass 22.
[0130]
Further, a light shielding roller 98 is provided as a conveying unit that conveys the document from the first reading unit 20 side to the second reading unit 30 side between the first reading unit 20 and the second reading unit 30 along the document conveyance direction. .
[0131]
Hereinafter, a configuration in the vicinity of the second reading unit 30 will be described with reference to FIG.
The upper surface of the second contact glass 22 juxtaposed to the first contact glass 21 forms a transport guide for guiding a document extending substantially horizontally in the document transport path 37. A cylindrical light-shielding roller 98, which is a conveying means, is in a pressure contact state or a non-contact state with a low pressure contact force at a substantially central portion of the upper surface of the second contact glass 22 in the document conveyance direction. 22 is arranged in a state where the gap with the upper surface of 22 is very narrow, that is, the gap is narrower than the thickness of the original. The light shielding roller 98 is formed of a light absorber that absorbs light, for example, a black rubber member. When the light shielding roller 98 is disposed so as to be in contact with the second contact glass 22, the peripheral surface of the light shielding roller 98 in contact with the second contact glass 22 is made of a material having a low friction coefficient with the upper surface of the second contact glass 22. It is formed. The light shielding roller 98 is slipped until the original reaches the contact portion between the second contact glass 22 and the light shielding roller 98. The rotating shaft of the light shielding roller 98 is rotatably supported by the frame of the upper housing 3 so as to be perpendicular to the document conveying direction. Further, the driving means installed on the back side of the upper housing 3 is rotated in the direction of the arrow F around the rotation axis extending perpendicular to the paper surface of FIG. 15 so as to convey the document downstream in the document transport direction. .
[0132]
The light shielding roller 98 is disposed so as to protrude from the opening 238 provided in the upper casing document guide 38C of the upper casing 3. Therefore, even if the upper casing document guide 38C vibrates, the light shielding roller 98 is held on the frame of the upper casing 3 so as not to vibrate. A plurality of positioning projections 61 are provided on the surface of the upper housing document guide 38C on the document conveyance path 37 side, and the document conveyance path 37 is defined as a predetermined gap. A light shielding member 213 made of a black sheet is attached to the opposite side of the light shielding roller 98 with the second contact glass 22 interposed therebetween.
[0133]
The surface of the upper housing document guide 38C of the present embodiment on the document conveyance path 37 side includes a region facing the first reading region 15 where the first reading unit 20 reads the document. The surface of the upper casing document guide 38C on the side of the document conveyance path 37 is a flat surface, and white paint is applied to the surface so as to be white and flat. This is because it is necessary to remove this influence from the data read by the reading unit when the surface of the document conveying path 37 opposite to the side where the reading unit is disposed is darker than the background of the document. . If the surface of the document transport path 37 opposite to the side on which the reading unit is disposed is uneven, the light transmitted through the document is reflected by the upper casing document guide 38C and is again transmitted through the document and read. This is because shading due to the unevenness occurs in the read image. Further, the light reflected by the upper casing document guide 38C is read by the first reading unit 20 on the surface of the upper casing document guide 38C on the upstream side in the document conveying direction of the first reading area 15 on the document conveyance path 37 side. The black sheet body is stuck so that there is no.
[0134]
The light emitted from the aperture 233A of the exposure lamp 233 of the first reading unit 20 is divided into light that directly strikes the document conveyed through the document conveyance path 37 and light that indirectly shines through the reflector 234. Also, the first reading area 15 is illuminated. By the way, the light reflected by the surface of the second contact glass 22 and the surface of the upper housing document guide 38C travels in the document transport path 37 or reflects in the second contact glass 22 and travels. However, since the light shielding roller 98 is disposed between the first reading unit 20 and the second reading unit 30 disposed along the document conveyance path 37, the light traveling in the document conveyance path 37 is blocked by the light shielding roller 98. Blocked by.
[0135]
Most of the light 200 that is reflected by the second contact glass 22 and travels and whose reflection angle is smaller than the total reflection angle passes through the second contact glass 22 as shown in FIG. The light is absorbed by the light shielding roller 98, the upper casing document guide 38C, or the light shielding member 90. The amount of light reflected to the inner side on the surface of the second contact glass 22 is not so much, but when this also comes out on the opposite side of the second contact glass 22, most of the light comes out to the outside, and the light shielding roller 98, and is absorbed by the upper casing document guide 38C or the light shielding member 90. In this way, even if the light is reflected many times inside the second contact glass 22, the light emitted to the outside is rapidly attenuated and is not read on the second reading unit 30 side.
[0136]
Further, since most of the light 201 reflected by the second contact glass 22 that travels after being reflected in the second contact glass 22 has a reflection angle close to or larger than the total reflection angle, as shown in FIG. Even if the inside of the glass 22 is subjected to multiple reflections, it is not read on the second reading unit 30 side.
[0137]
Similarly, the light from the LED array 80 that is the light source of the second reading unit 30 is not read on the first reading unit 20 side.
[0138]
As described above, in the double-sided image reading apparatus, the light from the light source 230 of the first reading unit 20 and the light from the LED array 80 of the second reading unit 30 pass through the document conveyance path 37 or inside the second contact glass 22. No optical interference occurs due to multiple reflections. Therefore, the original can be read satisfactorily.
[0139]
In addition, since the document is pressed against the second contact glass 22 by the light shielding roller 98, the document does not come into close contact with the second contact glass 22 when the document is conveyed, so that the document does not flutter. Therefore, the original can be read accurately.
[0140]
Further, the second reading unit 30 of the double-sided image reading device 6 of the present embodiment is configured to be detachable by opening an open door 33 provided on the upper portion of the upper housing 3 as shown in FIG. Further, the electrical configuration of the double-sided image reading device 6 is almost the same as the electrical configuration of the double-sided image reading device 1 shown in FIG.
[0141]
FIG. 19 is a schematic cross-sectional view of the vicinity of the second reading unit 30 of the double-sided image reading apparatus 7 which is still another embodiment of the present invention. The double-sided image reading device 7 can read a document in the stationary reading mode and the traveling reading mode, similarly to the double-sided image reading device 1 of the embodiment. In the double-sided image reading device 6 of the present embodiment, the same members as those of the double-sided image reading device 6 of the above embodiment are denoted by the same reference numerals, and description thereof is omitted. The double-sided image reading device 7 shown in FIG. 19 and the double-sided image reading device 6 shown in FIG. 18 differ in the configuration of the document conveying section 34, the first contact glass 21, and the second contact glass 22.
[0142]
In the double-sided image reading device 7, as in the case of the double-sided image reading device 6 of the above-described embodiment, between the first reading unit 20 arranged in the lower housing 2 and the second reading unit 30 arranged in the upper housing 3. Thus, the light shielding roller 98 is disposed in the upper housing 3. A transport roller 99 is arranged in the lower housing 21 at a position facing the light shielding roller 98. In order to dispose the conveyance roller 99, the end of the first contact glass 21 on the second contact glass 22 side is configured to be close to the conveyance roller 99 on the upstream side of the conveyance roller 99 in the document conveyance direction, An end portion of the second contact glass 22 on the first contact glass 21 side is configured to be a position close to the transport roller 99 on the downstream side of the transport roller 99 in the document transport direction. That is, the first contact glass 21 and the second contact glass 22 are configured so that the first reading unit 20 reads a document from below the first contact glass 21 in the traveling reading mode in which the document transport path 37 on the upper surface of the lower housing 2 is formed. Is configured.
[0143]
The conveyance roller 99 is a cylindrical light absorber, and its rotation axis extends at right angles to the document conveyance direction, and the rotation axis is supported by the frame of the lower housing 2. The transport roller 99 is disposed at a position in contact with the light shielding roller 98 of the upper housing 3. The transport roller 99 is rotatably provided around a rotation axis extending in a direction perpendicular to the paper surface of FIG. 19, and the light shielding roller 98 of the upper housing 3 is centered on a rotation axis extending in a direction perpendicular to the paper surface of FIG. By rotationally driving in the direction of the arrow G, the rotational force is transmitted and driven to rotate in the direction of the arrow H, and the document is nipped and conveyed at the contact portion with the light shielding roller 98.
[0144]
The first contact glass 21 and the end of the second contact glass 22 located downstream of the transport roller 99 in the document transport direction and the end of the first contact glass 21 positioned upstream of the transport roller 99 in the document transport direction A first guide sheet 96 and a second guide sheet 97 for closing the gap between the conveyance roller 99 and the gap between the second contact glass 22 and the conveyance roller 99 and guiding the document are provided. The first guide sheet 96 provided on the first contact glass 21 side is bonded to the end surface of the first contact glass 21 facing the conveyance roller 99 so as to convey the document to the contact portion between the light shielding roller 98 and the conveyance roller 99. And bent along the document conveyance path 37 toward the conveyance roller 99 side. Further, the surface of the first guide sheet 96 along the document conveyance path 37 is positioned slightly below the upper surface of the first contact glass 21. As a result, jamming of the original can be prevented.
[0145]
The second guide sheet 97 provided on the second contact glass 22 side is bonded to the end surface of the second contact glass 22 facing the conveyance roller 99 side, and the document from the contact portion between the light shielding roller 98 and the conveyance roller 99 is attached. Is bent along the document conveyance path 37 toward the conveyance roller 99 side. Further, the surface of the second guide sheet 97 along the document conveyance path 37 is positioned slightly above the upper surface of the second contact glass 22 on the second contact glass 22 side. As a result, jamming of the original can be prevented. The first guide sheet 96 and the second guide sheet 97 may be formed of a light absorber.
[0146]
As described above, in the double-sided image reading device 7, the light source of the first reading unit 20 is provided by arranging the light shielding roller 98 and the conveyance roller 99 between the first reading unit 20 and the second reading unit 30 in the document conveying direction. The light from 230 and the light from the LED array 80 of the second reading unit 30 are reflected through the document conveyance path 37 or within the first contact glass 21 and the second contact glass 22 to cause optical interference. Absent.
[0147]
Further, the light-shielding roller 98 and the transport roller 99 have a reduced roller diameter so as not to block the optical path between the first scanning unit 23 and the second scanning unit 24 of the first reading unit 20. Further, since the driving roller 99 is driven to rotate, no driving means is newly disposed in the lower housing 2, so that the manufacturing cost can be reduced.
[0148]
Further, since the document is transported by the light shielding roller 98 and the transport roller 99, the document does not flutter. Therefore, the original can be read accurately. Further, the electrical configuration of the double-sided image reading device 7 is substantially the same as the electrical configuration of the double-sided image reading device 1 shown in FIG.
[0149]
The above double-sided image reading devices 1, 5, 6, and 7 can be applied to a reading device that reads a document with a facsimile machine, a copying machine, or the like.
[0150]
【The invention's effect】
As described above, according to the present invention, the light shielding means for preventing the passage of light is disposed between the first conveyance guide and the second conveyance guide that are juxtaposed along the document conveyance direction. A first reading unit that is disposed on one side and that reads one surface of a document that is transported along the first transport guide, and is disposed on the other side of the second transport guide and is transported along the second transport guide. Light emitted when the second reading means for reading the other surface of the original reads the original enters the first conveyance guide and the second conveyance guide, respectively, and multiple reflections occur in the first conveyance guide and the second conveyance guide. Or after entering the first transport guide and the second transport guide, exits the transport path for transporting the document and undergoes multiple reflections, and enters the other reading means disposed on the opposite side of the transport guide. There is nothing. Therefore, optical interference can be prevented and images on both sides of the document can be read favorably.
[0151]
  MaTheSince the light shielding member is a light absorber that absorbs light applied to the end surfaces of the first and second transport guides facing the first and second transport guides, for example, black paint is used as the end surface. It is easy to form a light-shielding member by applying to. Further, since the light shielding member is formed on the end face by coating, the light shielding means can be arranged even if the gap between the first transport guide and the second transport guide is narrow.
[0152]
  Also according to the invention,Since the guide member that guides the document and prevents passage of light is disposed between the first transport guide and the second transport guide that are juxtaposed along the transport direction of the document and configured by the light transmitting body. A first reading unit that is arranged on one side of the conveyance guide and reads one surface of the document conveyed along the first conveyance guide, and is arranged on the other side of the second conveyance guide and along the second conveyance guide Light emitted when the second reading unit that reads the other surface of the conveyed document reads the document enters the first conveyance guide and the second conveyance guide, respectively. Multiple reflections at the other side, or after entering the first conveyance guide and the second conveyance guide, exiting the conveyance path for conveying the document and performing multiple reflections, and the other of the other arranged on the opposite side of the conveyance guide Intrusion into reading means There is no. Therefore, optical interference can be prevented. AlsoEven if the first conveyance guide and the second conveyance guide are misaligned, the document is guided by the guide member, and the design is easy.
[0153]
Further, according to the present invention, since the flexible sheet body is bonded to the end surface of the first conveyance guide or the second conveyance guide facing the first conveyance guide and the second conveyance guide, the light shielding means can be easily provided. Can design. In addition, since the light shielding member is a flexible sheet body, it is possible to guide the original by bending the flexible sheet body in a direction from the bonded guide to the other guide.
[0154]
Further, according to the present invention, the first reading that reads one side of the document conveyed along the conveyance guide on one side of the conveyance guide that is arranged along the conveyance direction of the document and is configured by a light transmitting body. The prospective angle of the second reading unit that is arranged on the downstream side in the conveyance direction of the first reading unit from the light source of the first unit and that reads the other side of the document conveyed along the conveyance guide is small. By tilting the conveyance guide on the second reading means side, that is, the conveyance guide opposed to the second reading means, optical interference between the two reading means can be prevented, so that the images on both sides of the document can be prevented. Can be suitably read.
[0155]
Further, according to the present invention, since the second reading unit is inclined in accordance with the inclination of the transport guide, optical interference between the first reading unit and the second reading unit can be further prevented, and the first Since the reading means need not be inclined, for example, the first reading means can be translated to read a stationary document.
[0156]
Further, according to the present invention, the first reading unit that requires a large space for the arrangement and reads the image in a reduced size is arranged below the conveyance guide, and the image does not need a large space for the arrangement and is read at the same magnification. Since the second reading unit is disposed above the conveyance guide, the apparatus can be reduced in size.
[0157]
  According to the invention, the first reading means is arranged along the conveyance direction of the document and reads one side of the document conveyed along the conveyance guide on one side of the conveyance guide made of a light transmitting body. And a second reader that reads the other side of the document that is arranged along the conveyance guide and is located downstream of the first reading means in the conveyance direction.StepArranged and transports the document in one direction between the first reading means and the second reading means with respect to the document transport guide transport directionAnd block the lightBy arranging the conveying means, it is possible to prevent the optical interference that the light from the first reading means or the second reading means is read by the other reading means, and it is preferable to read the images on both sides of the document. Can be done. For example, if the conveying means is a roller, the original can be conveyed while being pressed against the conveying guide by the roller, and the original can be read more faithfully because the original does not float from the original guide.
[0158]
Further, according to the present invention, the conveyance guide is configured separately by two parts, the facing part of the first reading means and the facing part of the second reading means, and the first reading means and the second reading means. Since a pair of rollers can be disposed between the two reading means to block light between the two reading means, it is possible to prevent optical interference that the light of one reading means is read by the other reading means. it can. In addition, optical interference due to stray light transmitted through the document guide can be prevented, and images on both sides of the document can be suitably read. Further, stable conveyance is possible by conveying the document sandwiched between a pair of rollers. Further, since the document can be prevented from floating from the conveyance guide by the pair of rollers, the document can be read more faithfully.
[0159]
According to the invention, since the roller has a light absorber, the light irradiated on the roller can be absorbed.
[0160]
Further, according to the present invention, even if the first reading means or the second reading means has two scanning units that move and scan, the roller is arranged at a position that does not block the optical path of both units. For example, a reading unit using a reduction optical system that reduces and reads an image can be used as the first reading unit and the second reading unit.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a double-sided image reading apparatus 1 according to an embodiment of the present invention.
2 is a cross-sectional view showing a configuration in the vicinity of a second reading unit 30 of the double-sided image reading apparatus 1. FIG.
FIG. 3 is an enlarged cross-sectional view showing the vicinity of a document conveying section 34 of the double-sided reading apparatus 1;
4 is a perspective cross-sectional view showing an installation configuration of an image sensor unit 35 of the double-sided image reading apparatus 1. FIG.
FIG. 5 is a diagram showing how the second reading unit 30 is attached.
FIG. 6 is a block diagram showing an electrical configuration of the double-sided image reading apparatus 1;
7 is a cross-sectional view showing another configuration example of the document conveyance path 37 of the double-sided image reading apparatus 1. FIG.
FIG. 8 is a cross-sectional view showing still another configuration example of the document conveying path 37 of the double-sided image reading apparatus 1;
FIG. 9 is a schematic cross-sectional view of a double-sided image reading apparatus 5 that is another embodiment of the present invention.
FIG. 10 is an enlarged cross-sectional view showing the vicinity of the document conveying section of the double-sided image reading apparatus 5;
11 is a cross-sectional view showing a configuration in the vicinity of the second reading unit 30 of the double-sided image reading apparatus 5. FIG.
12 is a diagram showing a state of attachment of the second reading unit 30 of the double-sided image reading device 5. FIG.
FIG. 13 is a schematic cross-sectional view of a double-sided image reading apparatus 6 that is still another embodiment of the present invention.
14 is an enlarged cross-sectional view showing the vicinity of the document conveying section 34 of the double-sided image reading apparatus 6. FIG.
15 is a cross-sectional view showing a configuration in the vicinity of the second reading unit 30 of the double-sided image reading device 6. FIG.
16 is a diagram illustrating an example of light from a light source 230 of the first reading unit 20 of the double-sided image reading device 6. FIG.
17 is a diagram showing another example of light from the light source 230 of the first reading unit 20 of the double-sided image reading device 6. FIG.
FIG. 18 is a diagram illustrating how the second reading unit 30 of the double-sided image reading device 6 is attached.
FIG. 19 is a cross-sectional view illustrating a configuration of a document conveying portion of a double-sided image reading apparatus 7 that is still another embodiment of the present invention.
[Explanation of symbols]
1, 5, 6, 7 Double-sided image reader
20 First reading unit
30 Second reading unit
21 First contact glass
22 Second contact glass
34 Document feeder
37 Document transport path
38A Upper case upper conveyance guide
38B Upper case lower conveyance guide
38C Upper case document guide
39 Document conveying means
80 LED array
90 Guide members
91 Flexible sheet body
95 Daylight
121,122 Black paint
98 Shading roller
99 Conveyor roller
230 Light source

Claims (10)

A first transport guide and a second transport guide that are juxtaposed along the transport direction of the document and are made of a light transmitting body;
A first reading unit having a light source and disposed on one side of the first conveyance guide and reading one surface of the document conveyed along the first conveyance guide;
Includes a light source, disposed on the other side of the second conveyance guide, met sided image reading apparatus and a second reading means for reading the other surface of the document sheet being conveyed on the second conveying guide,
It is formed by a light absorber applied to each end face of the first conveyance guide and the second conveyance guide that faces between the first conveyance guide and the second conveyance guide, and between the first conveyance guide and the second conveyance guide. A double-sided image reading apparatus, characterized in that a light-shielding means for preventing the passage of light is provided. A first transport guide and a second transport guide that are juxtaposed along the transport direction of the document and are made of a light transmitting body;
A first reading unit disposed on one side of the first conveyance guide and configured to read one surface of the document conveyed along the first conveyance guide;
A double-sided image reading apparatus including a second reading unit disposed on the other side of the second conveyance guide and configured to read the other surface of the document conveyed along the second conveyance guide;
Provided between the first conveying guide and the second conveying guide prevents the passage of light between the first conveying guide and the second conveying guide, and you characterized Rukoto includes a guide member for guiding the document both Surface image reading apparatus. The guide member is a flexible sheet member that adheres to an end face of the first or second transport guide that faces between the first transport guide and the second transport guide and guides the document. 2 sided image reading apparatus according. A conveyance guide which is arranged along the conveyance direction of the document and is configured by a light transmitting body;
A first reading unit having a light source and reading one surface of the document conveyed along the conveyance guide on one side of the conveyance guide;
A double-sided image reading apparatus that is disposed downstream of the first reading unit in the conveyance direction and includes a second reading unit that reads the other surface of the document conveyed along the conveyance guide on the other side of the conveyance guide; There,
The second reading unit has a light source for irradiating the conveyed document and a lighting port for collecting reflected light from the document, and a lighting port of the second reading unit from the light source of the first reading unit. the expected but viewing angle both sides image reading apparatus you characterized in that the tilted conveying guide of the second reading means side so as to decrease. The double-sided image reading apparatus according to claim 4, wherein the second reading unit is inclined in accordance with the inclination of the conveyance guide . The first reading unit reads an image by reducing it,
The second reading means reads an image at an equal magnification,
Said first reading means is disposed below the conveyance guide, the second reading unit duplex image reading apparatus according to claim 4 or 5, wherein Rukoto disposed above the conveying guide. A conveyance guide which is arranged along the conveyance direction of the document and is configured by a light transmitting body;
Conveying means for conveying the document in one direction along the conveying guide;
A first reading unit having a light source, disposed on one side of the conveyance guide, and reading one surface of the document conveyed along the conveyance guide;
A double-sided image reading apparatus having a light source and disposed on the downstream side of the first reading unit in the conveyance direction, and comprising a second reading unit that reads the other surface of the document conveyed along the conveyance guide;
Conveying means, disposed between the first reading means and the second reading means to the conveying direction of the document, both sides image reading apparatus you wherein Rukoto shielding light. The conveyance guide is divided and arranged in an area for the first reading means and an area for the second reading means,
It said conveying means, duplex image reading apparatus according to claim 7, wherein the Oh Rukoto a pair of rollers for transporting across the document. The roller, duplex image reading apparatus according to claim 8, wherein Rukoto to have a light absorber. The first reading means or the second reading means has two scanning units for moving and scanning,
Duplex image reading apparatus according to claim 9, wherein disposed an optical path of both units to a position where the rollers are not blocked and wherein Rukoto.

Images