JP2007036398A - Adf type image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ADF type image reading apparatus in which precision of shading compensation can be enhanced. <P>SOLUTION: Since a shading plate 28 is provided on the upper surface of a contact glass 26 and a reading unit 30 moves substantially in parallel with the contact glass 26, the optical path length from the reading unit 30 to the shading plate 28 is substantially identical to the optical path length from the reading unit 30 to a sheet on the contact glass 26. Consequently, accurate shading compensation data can be attained at a reading section 36 and precision can be enhanced when shading compensation of sensitivity is performed at a light source section 32 and/or the reading section 36. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image reading apparatus, and more particularly, to an ADF type image reading apparatus that includes a sheet conveying device (ADF) and does not have a flatbed scanner function.

Among conventional image reading apparatuses, there is a type that includes only a sheet conveying apparatus (ADF) that automatically supplies a sheet to an image reading portion and does not have a flat bed and a flat bed scanner function. Inside this type of image reading apparatus, there are a light source unit such as an LED, a reflection mirror for reflecting light emitted from the light source unit in a predetermined direction, and a reading unit such as a CCD that reads an image on a sheet. , And a carriage with a fixed position. Also, an inner guide painted in white is disposed above the reading portion (above the contact glass). As a result, light is emitted from the light source unit to the inner guide, and light (shading data) reflected by the inner guide is read by the reading unit, thereby performing shading correction of sensitivity in the light source unit and the reading unit.
JP-A-6-291944

  By the way, the inner guide is positioned above the contact glass, and the sheet is in contact with the upper surface of the contact at the time of image reading. Therefore, the optical path length from the carriage to the inner guide and the optical path length from the carriage to the sheet Will be different. Accordingly, there is a problem that accurate shading data cannot be obtained, and the shading correction of the sensitivity of the light source unit and the reading unit is not accurately performed.

  Further, in the conventional image reading apparatus, the inner guide may become dirty because a sheet or the like contacts the inner guide. When the inner guide becomes dirty, there is a problem that accurate shading data cannot be obtained, and the shading correction of the sensitivity of the light source unit and the reading unit cannot be performed accurately.

  Accordingly, an object of the present invention is to provide an ADF type image reading apparatus that can improve the correction accuracy of shading correction in consideration of the above circumstances.

  According to the first aspect of the present invention, a paper transport device that supplies paper to the image reading portion, a light source unit that emits light, and light reflected from the paper by irradiating the light emitted from the light source unit to the paper is received. A reading unit having a reading unit that reads information, a shading correction unit that is used for shading correction of sensitivity of the light source unit and / or the reading unit and irradiated with light emitted from the light source unit, and a flat unit An ADF type image reading apparatus having a glass member disposed on the image reading portion instead of a bed and in contact with the paper on the upper surface, wherein the reading unit is movable substantially parallel to the glass member The shading correction means is provided on the upper surface of the glass member, moves the reading unit substantially parallel to the glass member, and Characterized by receiving the light reflected by the Ingu correcting means by the reading unit.

  According to the first aspect of the present invention, the shading correction means is provided on the upper surface of the glass member of the image reading portion, and the reading unit is located with respect to the glass member so that the reading portion is positioned in the vicinity of the shading correction means. After being moved substantially in parallel, the light emitted from the light source unit is reflected by the shading correction means, and the reflected light is received by the reading unit, whereby the sensitivity of the light source unit and / or the reading unit is corrected by shading. .

  Here, since the shading correction means is provided on the upper surface of the glass member and the reading unit moves substantially parallel to the glass member, the optical path length from the reading unit to the shading correction means, and the reading unit to the upper surface of the glass member, The optical path length to the sheet is substantially the same. Accordingly, accurate shading correction data can be obtained by the reading unit, and correction accuracy when the sensitivity of the light source unit and / or the reading unit is subjected to shading correction can be improved. In the present specification, the “ADF type image reading apparatus” means an image reading apparatus of a type that includes a sheet conveying device (ADF) and does not have a flatbed scanner function among the image reading apparatuses. .

  According to a second aspect of the present invention, there is provided a sheet conveying device that supplies a sheet to an image reading portion, a light source unit that emits light, and a light beam emitted from the light source unit to receive the light reflected by the sheet. A reading unit having a reading unit that reads information, a shading correction unit that is used for shading correction of sensitivity of the light source unit and / or the reading unit and irradiated with light emitted from the light source unit, and a flat unit An ADF type image reading apparatus having a glass member arranged on the image reading portion instead of a bed and in contact with the paper on an upper surface thereof, wherein the reading unit is rotatably provided, and the shading is performed from the reading unit. The reading is performed so that the optical path length to the correction means is substantially the same as the optical path length from the reading unit to the sheet positioned on the upper surface of the glass member. Rotating the unit, characterized in that it received by reflected the reader light at said shading correction means.

  According to the second aspect of the present invention, the reading unit is arranged so that the optical path length from the reading unit to the shading correction means is substantially the same as the optical path length from the reading unit to the sheet positioned on the upper surface of the glass member. After the rotation, the light emitted from the light source unit is reflected by the shading correction unit, and the reflected light is received by the reading unit, whereby the sensitivity of the light source unit and / or the reading unit is corrected for shading.

  Here, when the reading unit is rotated, the optical path length from the reading unit to the shading correction means becomes substantially the same as the optical path length from the reading unit to the sheet positioned on the upper surface of the glass member. Accordingly, accurate shading correction data can be obtained by the reading unit, and correction accuracy when the sensitivity of the light source unit and / or the reading unit is subjected to shading correction can be improved.

  According to a third aspect of the present invention, in the ADF type image reading apparatus according to the first or second aspect, the reading unit is moved or rotated manually.

  According to the third aspect of the present invention, since the reading unit is moved or rotated manually, an apparatus for moving or rotating the reading unit becomes unnecessary. Thereby, it is possible to prevent the ADF type image reading apparatus from increasing in size and to prevent the manufacturing cost from increasing.

  According to a fourth aspect of the present invention, in the ADF type image reading apparatus according to any one of the first to third aspects of the present invention, the ADF type image reading apparatus includes a casing serving as an outer frame, and the shading correction unit includes the casing and the casing. It is provided by being sandwiched between glass members.

  According to the fourth aspect of the present invention, since the shading correction means is provided between the casing and the glass member, it is possible to reliably prevent dust and dirt from adhering to the shading correction means. . Thereby, it can prevent that the shading correction precision of the sensitivity of a light source part or / and a reading part falls. Moreover, since the shading correction means is provided between the casing and the glass member, the shading correction means can be reliably fixed inside the casing.

  According to the present invention, the accuracy of shading correction can be improved.

  Next, an ADF type image reading apparatus according to an embodiment of the present invention will be described with reference to the drawings. Note that the ADF type image reading apparatus of the present embodiment is premised on an image reading apparatus of a type having a sheet conveying device but not having a flat bed scanner.

  As shown in FIG. 1, the ADF type image reading apparatus 10 includes a housing 12 serving as an outer frame. A paper cassette 14 that stores paper is disposed at the lower portion of the housing 12. A jam paper removing cover 16 is provided on one side of the housing 12 so as to be freely opened and closed. An input unit 18 is provided on the upper part of one side surface of the housing 12. The input unit 18 is provided with a plurality of input buttons 18A and a liquid crystal display unit 18B for displaying predetermined information.

  In addition, a paper transport device (ADF) 20 is disposed on the top of the housing 12. Inside the sheet conveying device 20, a conveying roller (not shown) for supplying the sheet to the image reading portion A (see FIGS. 2 and 3) is provided. In addition, a paper feed tray 22 on which paper fed into the paper transport device 20 is placed is provided in the vicinity of the paper entrance of the paper transport device 20. A paper discharge tray 24 is formed on the upper surface of the housing 12 located in the vicinity of the paper discharge port of the paper transport device 20. The paper discharge tray 24 is located below the paper feed tray 22.

  As shown in FIGS. 2 and 3, a flat contact glass 26 is disposed on the upper portion of the housing 12 positioned at the image reading portion A of the sheet instead of the flat bed. A flat shading plate (shading correction means) 28 painted in white is disposed between the upper surface on the end side of the contact glass 26 and the lower surface of the upper portion of the housing 12. As described above, the upper surface of the shading plate 28 is in contact with the lower surface of the upper portion of the housing 12, and the lower surface is in contact with the upper surface of the contact glass 26, so that the shading plate 28 is not exposed to the outside. It has been. The shading plate 28 is not limited to the configuration provided at the above-described position, and may be provided at other sites as long as the configuration is provided on the upper surface of the contact glass 26.

  A reading unit 30 is disposed inside the housing 12. The reading unit 30 includes a light source unit 32 that emits light, a plurality of reflection mirrors 34 that reflect the light emitted from the light source unit 32 in a predetermined direction and irradiate the image reading region A, and a sheet or a shading group. The reading unit 36 that receives the reflected light of the light applied to the plate 28 is accommodated. In addition, a guide member 38 that extends substantially parallel to the contact glass 26 is provided inside the housing 12. The reading unit 30 is attached to the guide member 38 so as to be movable in the guide member axial direction (substantially parallel to the lower surface of the contact glass 26). The movement of the reading unit 30 can be manually performed from the outside of the housing 12. Note that a driving mechanism (not shown) for moving the reading unit 30 and a control unit (not shown) for controlling the driving mechanism. (Not shown) may be provided separately, and the reading unit 30 may be moved based on a control signal from the control unit.

  Next, the operation of the ADF type image reading apparatus 10 of this embodiment will be described.

  As shown in FIG. 2, before reading the image on the sheet, the reading unit 30 is manually moved to the shading correction position along the axial direction by the guide member 38. After the reading unit 30 is moved to the shading correction position, light is emitted from the light source unit 32. The light emitted from the light source unit 32 is reflected by the plurality of reflecting mirrors 34 and is applied to the shading plate 28 on the contact glass 26. When the shading plate 28 is irradiated with light, the light is reflected by the shading plate 28 and enters the reading unit 36. Based on the amount of light incident on the reading unit 36, the sensitivity of the light source unit 32 and the reading unit 36 is subjected to shading correction.

  Also, as shown in FIG. 3, when the shading correction of the sensitivity of the light source unit 32 and the reading unit 36 is completed, the reading unit 30 is manually moved below the image reading portion A. When the reading unit 30 is moved to the image reading portion A, the reading unit 30 is supplied to the image reading portion A by the paper transport device 20. When the sheet comes into contact with the upper surface of the contact glass 26, the light emitted from the light source unit 32 of the reading unit 30 is irradiated on the surface of the sheet through the plurality of reflecting mirrors 34. The light irradiated on the surface of the paper is reflected by the surface and is incident on the reading unit 36. Thereby, the surface image of the paper is read.

  As described above, before reading the front surface image of the paper, the reading unit 30 is moved substantially parallel to the lower surface of the contact glass 26 to irradiate the shading plate 28 disposed on the upper surface of the contact glass 26 with light. Since the sensitivity of the light source unit 32 and the reading unit 36 is subjected to shading correction based on the amount of the reflected light, the optical path length from the reading unit 30 to the shading plate 28 and the sheet on the upper surface of the contact glass 26 are measured. The optical path length is substantially the same. Accordingly, accurate shading correction data can be obtained by the reading unit 36, and correction accuracy when the sensitivity of the light source unit 32 and / or the reading unit 36 is subjected to shading correction can be increased.

  In particular, by adopting a configuration in which the reading unit 30 is manually moved, a driving mechanism and a control unit for moving the reading unit 30 are not necessary. Thereby, it is possible to prevent the ADF type image reading apparatus 10 from being increased in size and to prevent an increase in manufacturing cost.

  Further, since the shading plate 28 is provided between the upper portion of the housing 12 and the upper surface of the contact glass 26, it is possible to reliably prevent dust and dirt from adhering to the shading plate 28. Thereby, it can prevent that the shading correction precision of the sensitivity of the light source part 32 or / and the reading part 36 falls. Further, since the shading plate 28 is provided between the upper portion of the housing 12 and the upper surface of the contact glass 26, the shading plate 28 can be securely fixed inside the housing 12.

  Next, a modified example of the ADF type image reading apparatus 10 according to the above embodiment will be described.

  In the ADF type image reading apparatus 10 of the above-described embodiment, the configuration in which the reading unit 30 is moved substantially parallel to the lower surface of the contact glass 26 has been described as an example. However, the configuration is not limited to this configuration. For example, as shown in FIG. 4, instead of providing a guide member inside the housing 12, a rotation shaft 40 may be provided and the reading unit 42 may be provided so as to be rotatable around the rotation shaft 40. Good.

  At this time, the reading unit 42 can be manually rotated from the outside of the housing 12, and the optical path from the reading unit 42 to the shading plate 28 is further rotated by a predetermined angle. It is necessary to provide the shading plate 28 at a position where the optical path length is substantially the same as the optical path length from the reading unit 42 to the sheet positioned on the upper surface of the contact glass 26. Accordingly, when the shading correction is performed, the reading unit 42 is rotated about the rotation axis 40 by a predetermined angle, and the reflected light from the shading plate 28 is received by the reading unit 36, so that accurate shading correction data can be obtained. The shading correction accuracy of the sensitivity of the light source unit 32 and / or the reading unit 36 can be increased.

1 is a perspective view of an ADF type image reading apparatus according to an embodiment of the present invention. It is sectional drawing when the reading unit which comprises the ADF type image reading apparatus which concerns on one Embodiment of this invention is located in the shading correction position. It is sectional drawing when the reading unit which comprises the ADF type image reading apparatus which concerns on one Embodiment of this invention is located in the image reading site | part. It is sectional drawing when the reading unit which comprises the modification of the ADF type image reading apparatus which concerns on one Embodiment of this invention is located in the image reading site | part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ADF type image reading apparatus 12 Housing | casing 20 Paper conveyance apparatus 26 Contact glass (glass member)
28 Shading plate (shading correction means)
30 Reading Unit 32 Light Source 36 Reading Unit 42 Reading Unit

Claims (4)

A sheet conveying device that supplies the sheet to the image reading portion; a light source unit that emits light; and a reading unit that irradiates the sheet with light emitted from the light source unit and receives light reflected by the sheet and reads information. A reading unit; shading correction means for irradiating light emitted from the light source unit used for shading correction of the light source unit and / or sensitivity of the reading unit; and an image reading site instead of a flat bed. An ADF type image reading apparatus having a glass member disposed on the upper surface and in contact with the paper,
The reading unit is provided to be movable substantially parallel to the glass member,
The shading correction means is provided on the upper surface of the glass member,
An ADF type image reading apparatus, wherein the reading unit is moved substantially parallel to the glass member, and the light reflected by the shading correction means is received by the reading unit. A sheet conveying device that supplies the sheet to the image reading portion; a light source unit that emits light; and a reading unit that irradiates the sheet with light emitted from the light source unit and receives light reflected by the sheet and reads information. A reading unit; shading correction means for irradiating light emitted from the light source unit used for shading correction of the light source unit and / or sensitivity of the reading unit; and an image reading site instead of a flat bed. An ADF type image reading apparatus having a glass member disposed on the upper surface and in contact with the paper,
The reading unit is rotatably provided,
The shading correction is performed by rotating the reading unit so that the optical path length from the reading unit to the shading correction means is substantially the same as the optical path length from the reading unit to the sheet positioned on the upper surface of the glass member. An ADF type image reading apparatus, wherein the reading unit receives light reflected by the means.   The ADF type image reading apparatus according to claim 1, wherein the reading unit is moved or rotated manually. It has a casing that is an outer frame,
4. The ADF type image reading apparatus according to claim 1, wherein the shading correction unit is provided between the casing and the glass member. 5.

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