JP2006186430A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent dust adhering to a document from causing a flaw on the surface of a guide member opposing the reading section when the document is carried to the reading section, and to ensure proper reading of the document by making the self-weight of the document act on the body section side thereby applying the document to the reading face. <P>SOLUTION: The image reader comprises a body section 10 provided with a means 110 for reading data described on a document P, and a means 30 for conveying the document P to the reading face of the reading means 110. A guide member 210 being subjected to floating of the document P is provided at a position opposing the body section 10. The guide member 210 is provided with a recess 40 in a surface opposing the reading face, and a means 50 for sustaining a clearance between the guide member 210 and the reading face is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus that reads a document such as plain paper, coated paper, and film, and more particularly to a paper conveyance type image reading apparatus.

  As a specific configuration of the document reading apparatus, there is one disclosed in Patent Document 1. As shown in FIGS. 1, 4, 5, and 6, this configuration supports the shading plate 44 in a swingable manner so as to press the document against the reading surface 16 by its own weight. To do.

Under this configuration, when the document passes through the reading surface 16, the document is pressed by the weight of the shading plate 44 and is in close contact with the reading surface 16. On the other hand, when a thick document passes through the reading surface 16, the shading plate 44 rotates in a direction to escape from the pushing force from the document, and is pressed by the weight of the shading plate 44 from the position where the shading plate 44 is pushed up. Adheres closely to the reading surface 16.
JP-A-5-91243 ([0004] to [0005], FIG. 1, FIG. 4, FIG. 5, FIG. 6)

  However, in the above configuration, when the original is read, the surface of the shading plate 44 facing the reading surface 16 is in contact with the shading plate 44, and the shading plate 44 is caused by dust, dust, or the like adhering to the surface of the original facing the shading plate 33. There is a high possibility that proper shading correction cannot be performed and the original cannot be read properly.

  Further, when a document to be read has a crease or has a portion that is strongly stiff and lifted, the edge of the crease or the lifted portion cannot be crushed by the weight of the shading plate 44. For this reason, the document remains floating on the reading surface 16, and there is a possibility that proper reading cannot be performed. In particular, it becomes prominent when the crease is in the transport direction.

  In order to solve the above-described problem, the present invention includes a main body unit including a reading unit that reads data described in a document, and a transport unit that transports the document to a reading surface of the reading unit. A guide member that receives the lift of the document is provided at the opposite position, and the guide member is formed with a recess on the surface facing the reading surface, and the guide member is maintained with an appropriate gap with respect to the reading surface. An urging means is provided.

  According to a second aspect of the present invention, the concave portion receives light from the light source when performing shading correction. Further, according to a third aspect of the present invention, the biasing means is provided with a switching means for switching the biasing force of the biasing means.

  The present invention includes a main body unit provided with a reading unit that reads data described in a document, and a transport unit that transports the document to a reading surface of the reading unit. The guide member is provided with a receiving member, and a concave portion is formed on the surface facing the reading surface, and the guide member is provided with a biasing means for keeping an appropriate gap with respect to the reading surface. When the document is conveyed to the reading unit, the surface of the guide member facing the reading unit is prevented from being scratched by dust or dirt adhering to the document. A proper original can be read by contacting the reading surface.

  According to the second aspect of the present invention, it is possible to perform appropriate shading correction without damaging the surface of the concave portion by receiving the light of the light source when performing the shading correction in the concave portion. Further, in claim 3, by providing a switching means for switching the urging force of the urging means, the guide member receives a force (biasing force) for lifting the document through the urging means, and prevents the document from being lifted, Appropriate reading can be performed.

  A preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a schematic diagram of an image reading apparatus of the present invention. This image processing apparatus is applied as an image scanner that can be connected to a print output apparatus such as an LED printer. Of course, the present invention can also be applied to a copying machine in which a scanner unit and a printer unit are integrated.

  The image scanner is a scanner capable of reading a large-size paper document up to, for example, A0 size, a main body unit 10 that reads data written on the document P, an upper lid 20 that can be lifted in the direction of arrow a, It is comprised with the conveyance means 30 which conveys the original P. Note that the data described in the document P refers to images, characters, or data including these.

  The main body 10 includes a reading unit 110, and a feed roller 120a and a conveyance roller 120b disposed so as to sandwich the reading unit 110. The reading unit 110 is a reduction optical system, and includes a first mirror 111, a second mirror 112, a third mirror 113, a reflecting plate R, a projection lens 115, and image sensors (L1, L2, L3,... -) Comprises an image sensor 119 arranged in a line, a light source 116, and a fixed base 114.

  A first mirror 111, a second mirror 112, and a third mirror 113 are arranged on the fixed base 114 at a predetermined angle so that the light from the light source 116 reflected on the document reaches the image sensor. With such a mirror arrangement, the light path of the light source 116 is bent to reduce the size of the apparatus.

  With such a configuration, the light of the light source 116 reflected on the document is condensed by the projection lens 115 via the first mirror 111, the second mirror 112, and the third mirror 113 and is read by the image sensor 119. .

  In this embodiment, the reading unit 110 is a reduction optical system. However, the reading unit 110 is not limited to this, and as shown in FIG. 2, a sensor with a red filter 121, a sensor 122 with a green filter, You may comprise by the sensor 123 with a blue filter, the fixing stand 114, the lens 115, and the light source 116. FIG.

  In this configuration, the line sensor 121 with a red filter, the line sensor 122 with a green filter, and the line sensor 123 with a blue filter are attached by a fixed base 114. Furthermore, each sensor has a plurality of semiconductor sensor elements arranged in a line to read the reflection of the original P irradiated by the light source 116 collected by the lens 115 through the contact glass 117.

  The upper lid 20 is provided with a front pressing roller 220, a guide member 210, and a rear pressing roller 230 in this order from the document insertion side. A grip portion 240 is provided on the document insertion side of the upper lid 20, and the rear end portion 21 on the opposite side is pivotally supported by the main body portion 10. Accordingly, the upper lid 20 can open the reading surface of the contact glass 117 and the like by lifting the gripping portion 240 in the direction of arrow a. Further, a restricting portion 118 is disposed on the guide member 210 side where the leading edge of the document P reaches first. The regulating portion 118 is attached to the upper lid 20 with one end inclined to the contact glass 117 side.

  When the upper lid 20 is returned to the original position (the state shown in FIG. 1), the front presser roller 220 disposed on the document insertion side is attached to a position facing the feed roller 120a and disposed on the document discharge side. The rear presser roller 230 is attached at a position facing the transport roller 120b.

  The feed roller 120 a is a roller that conveys the inserted document P onto the contact glass 117, that is, to a reading position (reading surface) by rotating while being in contact with the front pressing roller 220. The conveying means 30 is constituted by the feed roller 120a and the front pressing roller 220, the rear pressing roller 230, and the conveying roller 120b.

  The guide member 210 prevents the original P conveyed to the reading surface from being lifted, and is provided so as to cover the contact glass 117 from directly above.

  Further, specifically, the guide member 210 is a combination of white thin plate materials or integrally formed, and can be smoothly conveyed to the reading surface to the guide member 210 portion where the leading edge of the document P reaches first. Thus, the introduction part 211 whose peripheral surface is formed in an arc shape is provided.

  Further, a recess 40 is formed on the surface of the guide member 210 facing the contact glass 117. The recess 40 receives light emitted from the light source 116 when performing shading correction. The flat portion 212 other than the recessed portion of the recessed portion 40 is arranged with a predetermined interval with respect to the contact glass 117. Note that the distance between the contact glass 117 and the flat portion 212 is set to be substantially the same as the thickness of the original P to be read.

  The guide member 210 is provided with a biasing means 50. The urging means 50 urges the guide member 210 toward the contact glass 117 by a spring or the like so that the contact glass 117 and the flat portion 212 have a constant interval, and the original conveyed from the original insertion side. This prevents the lifting force of P. The urging unit 50 is provided with an adjusting unit 60 that adjusts the urging force of the urging unit 50 according to the characteristics of the document P.

  The adjusting means 60 switches the urging force of the urging means 50 stepwise via an adjusting mechanism (not shown) by operating a lever 60 attached to a mounting plate (not shown). . The above-mentioned characteristics of the original P include, for example, the original size (long, indeterminate, regular, etc.), original material (plain paper, coated paper, glossy paper, etc.), thickness, and original folding. There is presence or absence.

  Next, the operation of the image reading apparatus of the present invention will be described. First, when the document P is normally read before the document P is set on the original insertion side, the upper cover 20 is opened and the lever 60 is operated as shown in FIG.

  As will be described later, when the leading edge of the document P enters the guide member 210 and the leading edge of the document P hits the introduction portion 211 of the guide member 210, the biasing force is absorbed by the biasing means 50 and read. This is to enable smooth movement to the part side. Thereafter, the upper lid 20 is closed, the document P is set on the document insertion side, and conveyance of the document P is started.

  As shown in FIG. 4A, when the leading edge of the document P is conveyed to the guide member 210 side in a state of being warped upward (on the upper lid 20 side), the leading edge of the document P is contact glass by the restricting portion 118. It is regulated to face 117 side. Further, when the document P is fed out, the leading end of the document P abuts against the introduction portion 211 of the guide member 210 as shown in FIG.

  At this time, the guide member 210 receives an urging force acting on the leading end portion of the document P, and is guided so that the leading end of the document P faces the contact glass 117, thereby preventing the leading end portion of the document P from being lifted. At the same time, the leading end portion of the document P comes into contact with the contact glass 117 by its own weight. Thereafter, the document P is sequentially transported to the reading surface by the transport unit 30 without the front end of the document P being in contact with the concave portion 40, and the data written on the document P is read.

  Even if the leading edge of the document P does not face the contact glass 117 side, the warping portion of the document P is regulated by the regulation unit 118 and the introduction unit 211. As shown in FIG. 5, the warped portion (projection amount) of the document P is so small that the reading of the document P is not affected.

  Further, in this state, the leading edge of the document P is slightly rubbed against the lower surface of the flat portion 212 and hardly touches. Therefore, the concave portion 40 that enters from the lower surface of the flat plate portion does not contact the front end of the document P. As a result, even if the document P is conveyed to the reading unit with the leading edge of the document P warped, the recess 40 does not contact the recess 40 and is prevented from being damaged, and appropriate shading correction is performed. Can be done.

  Next, a case where a document P with folds is read will be described. When reading a document P with a crease, the lever 60 is operated as shown in FIG. 6 to increase the biasing force of the biasing means 50. The following occurs when the urging force of the urging means 50 is set for a normal document P.

  As described in the normal reading of the original P, the front end of the original P enters the guide member 210, the front end of the original P abuts against the introducing portion 211 of the guide member 210, and the urging force is absorbed by the urging means 50. Then, it moves smoothly to the reading unit side. Further, when the document P is continuously conveyed, a portion where the document P is folded moves.

  Since the urging force concentrates on the protruding portion where the document P is folded, that is, the edge portion, the urging force becomes stronger than the urging force of the floating portion described above. In this state, when it abuts against the introduction portion 211 of the guide member 210, the urging force of the urging means 50 set for the normal document P is defeated by the urging force at the edge portion, and the guide member 210 is moved to the upper lid 20 side. shift.

  As a result, even if the protruding portion of the edge portion of the document P is suppressed by the restricting portion 118 and the biasing force of the biasing means 50 defeated, the edge portion cannot be brought into contact with the contact glass 117. As shown in FIG. 7, the image of the light projected onto the edge portion is shifted as shown by the broken line between the image-capturing elements C1, C2, C3... (CCD in the drawing). , Read in an interrupted state.

  Further, as shown in FIG. 2, a sensor composed of a sensor with a red filter 121, a sensor with a green filter 122, a sensor with a blue filter 123, a fixing base 114, a lens 115, and a light source 116, The vicinity of the edge (folded) portion is blurred when read, and the original P cannot be read accurately. In FIG. 7, the document is conveyed toward the front side.

  For this reason, when the original P including the fold is read, the urging force of the urging means 50 is increased so that the fold of the original P can be read. As shown in FIG. 8A, after the urging force of the urging means 50 is set, the upper lid 20 is closed, the original P is set on the original insertion side, and the conveyance of the original P is started.

  Thereafter, as shown in FIG. 8B, when the document P is conveyed to the guide member 210 side in a state folded to the upper lid 20 side, the bent portion of the document P is crushed and bent by the restriction unit 118. The protruding amount of the part is reduced. Further, when the document P is fed out, the leading end of the document P abuts on the introduction portion 211 of the guide member 210.

  At this time, the urging force of the urging unit 50 overcomes the urging force generated at the edge (bending) portion of the document P, and the guide member 210 is moved through the introduction portion 211 by the urging force of the urging unit 50. The edge (folded) portion of the document P is pressed, and the edge (folded) portion of the document P is further crushed to be in contact with the contact glass 117 in FIG.

  In this state, the document P is gradually moved to the reading surface side by the conveying means 30. During this time, the portion of the flat portion 212 irradiated with the light source 116 is formed in the concave portion 40, and therefore the edge (bending) portion of the document P moves without contacting the concave portion 40. As a result, it is possible to read the document P without damaging the portion of the flat portion 212 that receives the light emitted from the light source 116 when performing shading correction.

  In this embodiment, when the document P is folded, the urging force of the urging means 50 is switched to a stronger urging force than usual. However, the present invention is not limited to this, and the waist is strong. This may be applied when the urging force of the document P is strong and cannot be pressed by the guide member 210, such as when the document P is read.

  In the above description, the document is bent upward in the conveyance direction, but the same effect can be obtained even if the document is bent downward. Furthermore, the same effect can be obtained even if the lift occurs in the direction perpendicular to the transport direction.

  As described above, the recess 40 is formed in the guide member 210 on the surface facing the reading surface, and the urging means 50 for receiving the lifting force of the document P is provided on the guide member 210, and the urging force of the urging means 50 is provided. Accordingly, the guide member 210 is kept at an appropriate gap with respect to the reading surface, so that when the document P is transported to the reading unit, the guide member facing the reading unit due to dust, dust, or the like attached to the document P. It is possible to prevent the surface 210 (recess 40) from being damaged.

1 is a schematic cross-sectional view of an image reading apparatus of the present invention. The figure which shows the other Example of a reading means. The figure which adjusts the urging | biasing force of a biasing means with an adjustment means (lever). FIG. 6A is a diagram illustrating a document conveyance state, in which FIG. 5A illustrates a state in which a document along the upper side is conveyed to the contact glass side, and FIG. FIG. FIG. 6 is a main part enlarged view showing a state in which the leading edge of the document is conveyed from the state to the reading surface in FIG. 5. The figure which operates the adjustment means (lever) from the state of FIG. 2, and switches the biasing force of a biasing means. FIG. 4 is a diagram illustrating a state in which a folded original is read and detected by an image sensor of an image sensor. (A) is a schematic diagram for explaining conveyance of a folded document to a reading surface, (b) is a diagram viewed from a cross section A_A, and (c) is a diagram viewed from a cross section B_B.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Main-body part 20 Upper cover 30 Conveying means 40 Recessed part 50 Energizing means 60 Adjusting means P Original

Claims (3)

A main body provided with a reading unit for reading data described in the document, and a conveying unit for conveying the document to the reading surface of the reading unit,
At a position facing the main body, a guide member for receiving the lifting of the document is provided,
The guide member has a recess formed on a surface facing the reading surface, and is provided with a biasing means for keeping the guide member at an appropriate gap with respect to the reading surface. An image reading apparatus.   The image reading apparatus according to claim 1, wherein the concave portion receives light from a light source when performing shading correction.   The image reading apparatus according to claim 1, wherein the urging unit includes a switching unit that switches an urging force of the urging unit.

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