JP2005322956A - Image reading device - Google Patents

Abstract

An image reading apparatus that reads information on a document surface suppresses a change in color of a document dark and light portion and prevents a shadow from appearing in a read image.
A condensing unit 117 condenses a light beam on an image reading area 100 on a document surface, and a reading unit 107 that reads reflected light of the surface of the document 102 collected by the condensing unit 117 as image information. The light condensing means 117 includes a light source 110, a reflecting member 114 that reflects a part of the light beam emitted from the light source 110, and the direct light emitted from the light source 110 and the reflecting member 114 reflected. An image reading apparatus comprising: an opening for irradiating a part of reflected light to the image reading region.
[Selection] Figure 2

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus, and more particularly to a light condensing for reading an image on a document surface by irradiating a reading area on a document surface with a light beam from a light source and guiding the light beam reflected on the document surface to a solid-state imaging device. The present invention relates to an image reading apparatus including a unit.

  A conventional image reading apparatus will be described below.

  FIG. 4 is a cross-sectional view showing an image reading unit of a conventional image reading apparatus.

  Reference numeral 1 denotes a light source lamp, which is included in a lamp case 3 having an opening 2 provided with a constant width in the major axis direction. Reference numeral 4 denotes a lamp unit frame that holds a lamp case 3 that encloses the light source lamp 1. Here, the opening 2 is arranged so that the light beam from the light source lamp 1 directly reaches the image reading area 6 of the document table glass 5. Reference numeral 7 denotes a light source reflecting plate that is disposed so as to reflect a part of the light flux from the light source lamp 1 and reach the image reading area of the document table glass 5. Reference numeral 8 denotes a document placed on the document table glass 5 and is conveyed on the document table glass 5 in the direction of arrow A by a document conveyance unit (not shown), thereby reflecting the reflected light beam from the light source lamp 1 (on the document surface). The reflected light flux) is directed to a scanning mirror and an imaging lens (not shown) provided at the lower part of the platen glass 5, and is read as image information by a reading means.

Further, (Patent Document 1) discloses an image reading apparatus capable of illuminating a document while improving illumination efficiency and not affected by the reflection density of the document. As shown in FIG. 2, a document illuminating device that illuminates a reading area of a document surface placed on a document table glass in a slit shape with a light beam emitted from a light source having a long-axis cylindrical shape, A fluorescent resin plate in which a fluorescent dye is dissolved in a transparent resin is disposed in the vicinity of the glass, and a reading area on the original surface is illuminated using a light beam that passes through the fluorescent resin plate.
Japanese Patent Laid-Open No. 10-4473

  In the prior art described above, the diffracted light of the lamp light source and the light irradiated into the lamp case other than the opening of the lamp case are diffusely reflected in the lamp case, and the aperture is opened at various angles to the document reading line. The part was radiated and irradiated. As a result, there is a problem in that the color of the border between the original dark and light portions changes in the read image and appears as a shadow in the light portion following the dark portion.

  Further, in the configuration of (Patent Document 1), although the irradiation efficiency of the light source is increased, the document table glass passes through a fluorescent resin plate in which a fluorescent dye is dissolved in a transparent resin, as in the conventional technique described above. The original is irradiated to the area where the image reading is adversely affected by the luminous flux reaching, and the border of the original dark and light part changes in the read image, and the color changes and appears as a shadow in the light part following the dark part. there were.

In order to solve the above problems, the present invention has a condensing unit for condensing a light beam on a reading area of the original surface and a reading unit for reading reflected light of the original surface collected by the condensing unit as image information. The condensing means irradiates the image reading region with the light source, the reflecting member that reflects a part of the light beam emitted from the light source, and the direct light emitted from the light source and the reflected light reflected by the reflecting member. It is set as the structure provided with the opening part to do.

  As a result, the diffracted light of the lamp light source or the light irradiated into the lamp case other than the opening of the lamp case can be prevented from changing the color of the border of the original shading due to the irregular reflection in the lamp case. It becomes possible.

  As described above, according to the present invention, the light collecting means for condensing the light flux on the reading area of the original surface and the reading means for reading the reflected light of the original surface collected by the light collecting means as image information are provided. The condensing means images a light source, a reflecting member that reflects a part of the light beam emitted from the light source, a direct light emitted from the light source and a part of the reflected light reflected by the reflecting member. An image reading apparatus having an opening for irradiating a reading area, and a light beam from a light source is applied only to the reading area of the document, so that a change in the color of the original shading portion is suppressed, and a shadow generated in the read image is suppressed. By preventing this, a good read image can be obtained.

  According to a first aspect of the present invention, there is provided a condensing means for condensing a light beam on a reading area of the original surface, and a reading means for reading reflected light of the original surface collected by the condensing means as image information. The light collecting means includes a light source, a reflecting member that reflects a part of the light beam emitted from the light source, and direct light emitted from the light source and a part of the reflected light reflected by the reflecting member in the image reading area. An image reading apparatus having an opening for irradiating, even if diffracted light from a lamp light source or light irradiated in a lamp case other than the opening of the lamp case is diffusely reflected and emitted in the lamp case Since the light beam applied to the document surface is collected at the opening, the light beam can be applied only to the reading area.

  The invention according to claim 2 of the present invention has a condensing means for condensing the light beam on the reading area of the original surface and a reading means for reading the reflected light of the original collected by the condensing means as image information. The light collecting means includes a light source, a reflecting member that reflects a part of the light beam emitted from the light source, and an inner member that includes the light source and includes a first opening through which the light beam emitted from the light source passes. An image reading apparatus including a direct light that has passed through the first opening and a second opening that irradiates the image reading region with a part of the reflected light reflected by the reflecting member. Since the read light beam is not irradiated to the reading area, only the direct light of the light source lamp and the reflected light of the light source reflector can be accurately collected.

  The invention according to claim 3 of the present invention is the invention according to claim 1 or 2, wherein the second opening has a width in the main scanning direction of the reading device wider than the maximum readable document width and a width in the sub scanning direction. An image reading apparatus having a width narrower than a width of a light beam incident on a platen glass surface from a light source and narrower than a width of a light beam reflected from a light source by a reflecting member and incident on a glass platen surface. Since the light is condensed by the opening, the light beam from the light source can be accurately irradiated only on the reading region.

  According to a fourth aspect of the present invention, there is provided the image reading device according to the first, second or third aspect, wherein the light beam from the light source passes through the original platen glass. Since the light beam is condensed immediately before the operation, the light beam can be effectively narrowed down to only the reading region.

  The invention according to claim 5 of the present invention is the image reading apparatus according to claim 1, 2, 3 or 4, wherein the second opening is formed on a black resin sheet. Since the member having good characteristics is used, the portion other than the opening can be easily colored in black.

  The invention according to claim 6 of the present invention is the image reading device according to claim 1, wherein the second opening is formed in a black felt material. By using an elastic member, it is possible to increase the adhesion between the light collecting means and the housing, and to prevent leakage of light flux.

  According to a seventh aspect of the present invention, in the first, second, third, fourth, fifth, or sixth aspect, the second opening irradiates a light beam from the light source only on a reading area of the document surface. In the image reading apparatus, since irregularly reflected light or diffracted light from the light source is not irradiated to a region other than the reading region on the document surface, there is an effect that a change in image density can be prevented.

  According to an eighth aspect of the present invention, an original table glass on which an original is placed, a condensing means for condensing a light beam onto a reading area on the original surface placed on the original table glass, and a condensing means. Reading means for reading the reflected light of the original surface as image information, and the light collecting means includes a light source and a first opening that contains the light source and through which the light beam emitted from the optical recording light source passes. An image reading apparatus comprising: an inner member having a reflecting member that reflects a part of a light beam that has passed through a first opening; and a shielding member having a slit between a platen glass and a light source, Even if diffracted light from the light source or light irradiated in the lamp case other than the slit of the lamp case is diffusely reflected and radiated in the lamp case, an unnecessary reading area is required before reaching the document surface on the platen glass. The light beam applied to the Because the bets, has the effect that the light beam from the light source only in the reading area can be favorably illuminated.

  The invention according to claim 9 of the present invention is the image reading apparatus according to claim 8, wherein the shielding member is configured such that the light source side surface is black, and the diffracted light from the light source or inside the lamp case. It is possible to shield the irregular reflection at the point just before passing through the platen glass.

  The invention according to claim 10 of the present invention is the image reading apparatus according to claim 8, wherein the shielding member is black on both the upper and lower surfaces, and the light beam irradiated to other than the slit is the shielding member on the upper and lower surfaces of the slit. It has the effect that it can be absorbed in the black part.

  Next, Embodiment 1 of the present invention will be described with reference to FIGS.

(Embodiment 1)
1 is a configuration diagram showing the structure of an image reading apparatus according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view showing a condensing means provided in the image reading apparatus of FIG. 1, and FIG. FIG. 3B is an enlarged top view showing another shielding member provided in the light collecting means of FIG. 2.

  First, in FIG. 1, reference numeral 101 denotes a transparent platen glass provided in a conveyance path (not shown) for sending an original 102 in the direction of arrow A, and an image is transferred while the original 102 is being conveyed by an unillustrated original conveying means. Read. Reference numeral 103 denotes a light source unit (lamp unit) which will be described later. An image reading unit 104 includes an optical system including a plurality of mirrors 105 (not shown). The light source unit 103 irradiates the reading surface of the document 102 on the document table glass 101 with light. And an optical system for allowing the image to enter a document detection unit (described later) through an optical path indicated by an arrow B in the drawing via the mirror 105. The image reading unit 104 includes a line image sensor 107 serving as a reading unit, and an optical lens 106 that causes the light passing through the mirror 105 to form an image on the line image sensor 107. The line image sensor 107 is known as a CCD image sensor. A control unit 108 processes image data from the line image sensor 107.

Next, the light condensing means 117 according to the embodiment of the present invention will be described with reference to FIG. 11
0 is a light source for illuminating the document 102 (hereinafter referred to as a light source lamp), 111 is a cylindrical lamp case containing and holding the light source lamp 110, 112 is a lamp unit frame, and 113 is a long axis of the lamp case 111. A part of the light beam emitted from the light source lamp 110 is radiated from the first opening 113 at the first opening provided in the direction. Here, the lamp case 111 is disposed in the first opening 113 so that the light beam emitted from the light source lamp 110 directly reaches the image reading region 100 of the platen glass 101. Reference numeral 114 denotes a reflecting member that reflects a part of the light flux from the light source lamp 110 and reaches the image reading area 100 of the document table glass 101. The lamp case 111 and the reflecting member 114 are attached to the lamp unit frame 112.

  The light source lamp 110, the lamp case 111, the lamp unit frame 112, and the reflecting member 114 constitute a lamp unit (light source unit) 103. A shielding member 115 is attached in close contact with the lower surface of the platen glass 101 and has a second opening 116 formed therein.

  Here, in FIG. 3, the shielding member 115 is colored in black except for the second opening 116. As a material of the shielding member 115, it is preferable to use a resin sheet or a felt material. When these materials are used, it becomes easy to color black. Further, by using the felt material, the adhesion with the lamp unit 103 is increased, and light leakage from the joint can be prevented. FIG. 3 shows an example in which the front and back (upper and lower) surfaces are colored black. However, the light source lamp 110 may be colored black at least on the rear surface, in other words, attached to the platen glass 101. The second opening 116 has an opening width L1 in the main scanning direction that is wider than the maximum readable document width of the image reading apparatus. Further, the sub-scanning direction width L2 is narrower than the width of the light beam directly incident on the surface of the platen glass 101 from the light source lamp 110, and is the width of the light beam directly reflected on the surface of the platen glass 101 reflected from the light source lamp 110 by the reflecting member 114. Narrower width. Thereby, it is possible to accurately irradiate only the image reading region 100 with the light flux from the light source.

  Further, the shape of the second opening 116 shown in the embodiment of the present invention is an example, and is not limited to the present invention. The second opening 116 can irradiate a reading area of a document with a light beam from a light source. If so, for example, the shape as shown in FIG.

  Furthermore, it has been described that the shielding member 115 is attached in close contact with the lower surface of the platen glass 101. However, the attachment method may be attached with an adhesive, a screw, or the like as long as the attachment is possible.

  That is, in the light condensing means in the embodiment of the present invention, the light beam irradiated from the light source lamp 110 is attached by closely attaching the shielding member 115 provided with the second opening 116 to the back side of the platen glass 101. Even if the diffracted light or the light beam irradiated from the first opening 113 of the lamp case 111 is irregularly reflected in the lamp unit 103, the light other than the shielding member 115 and the second opening 116 before reaching the document surface. Unnecessary luminous flux is cut at the part. In other words, since the shielding member 115 has a black color other than the second opening 116, the light of the light beam irradiated to the part other than the second opening 116 is absorbed by the shielding member 115. Therefore, only the direct light of the light source lamp 110 and the reflected light of the reflecting member 114 are collected on the original reading surface, and the change in color of the original dark and light portion is suppressed, and no shadow appears in the read image. Contrast is clear. Further, since the shielding member 115 is attached in close contact with the lower surface side of the document table glass 101 (if the shielding member 115 is provided on the surface of the document table glass 101, a misfeed occurs when the document 102 is conveyed). Since the shielding member 115 is provided on the back surface of the glass 101, there is no influence on the document conveyed on the surface (upper surface) of the platen glass. Therefore, misfeed is suppressed.

  Further, as an example, the present invention is configured to irradiate the original reading area on the platen glass in a slit shape, and the slit provided in the shielding member has a maximum width in the main scanning direction of the image reading apparatus. The width in the sub-scanning direction is wider than the readable original width, and the width in the sub-scanning direction is narrower than the width of the light beam directly incident on the original platen glass surface from the light source and narrower than the width of the light beam reflected from the light source by the reflecting member and incident on the original platen glass surface. It is a thing. As a result, even if diffracted light from the lamp light source or light irradiated into the lamp case other than the opening of the lamp case is diffusely reflected and radiated in the lamp case, before reaching the document surface on the platen glass A light beam irradiated to an unnecessary area is cut by a slit. The shielding member is a member provided with a slit in a black resin sheet or a member provided with a slit in a black felt material. Further, the upper and lower surfaces of the shielding member are black. As a result, it is possible to reduce the influence of some of the reflected light that occurs on the surface of the platen glass and the back surface of the platen glass.

  An image reading apparatus including a light condensing unit according to the present invention can suppress a change in color of an original dark and dark portion and prevent a shadow from appearing in a read image. A scanner device, a digital copying machine, a digital multifunction peripheral, This is a technique that can be widely used, such as FAX and electronic filing device.

1 is a configuration diagram showing the structure of an image reading apparatus according to Embodiment 1 of the present invention. Sectional drawing which shows the condensing means with which the image reading apparatus of FIG. (A) An enlarged top view showing a shielding part provided in the light collecting means in FIG. 2, (b) An enlarged top view showing another shielding member provided in the light collecting means in FIG. Sectional drawing which shows the image reading part of the conventional image reading apparatus

Explanation of symbols

100 Image reading area 101 Document glass 102 Document 103 Lamp unit (light source)
104 Image Reading Unit 105 Mirror 106 Optical Lens 107 Line Image Sensor (Reading Unit)
108 Control Unit 110 Light Source (Light Source Lamp)
111 Lamp Case 112 Lamp Unit Frame 113 First Opening 114 Reflecting Member 115 Shielding Member 116 Second Opening (Slit)
117 Condensing means

Claims (10)

A condensing unit that condenses the light flux on a reading area of the document surface; and a reading unit that reads reflected light of the document surface collected by the condensing unit as image information. A reflecting member that reflects a part of the light beam emitted from the light source, and an opening that irradiates the image reading area with the direct light emitted from the light source and the reflected light reflected by the reflecting member. An image reading apparatus characterized by that. Condensing means for condensing a light beam on a reading area of the original surface, and reading means for reading reflected light of the original collected by the condensing means as image information, wherein the condensing means includes a light source, A reflection member that reflects a part of the light beam emitted from the light source; an inclusion member that includes the light source and includes a first opening through which the light beam emitted from the light source passes; and the first opening portion. An image reading apparatus comprising: a second opening that irradiates the image reading region with the direct light that has passed through the light and a part of the reflected light reflected by the reflecting member. The width of the second opening in the main scanning direction of the reading device is wider than the maximum readable document width, the width in the sub scanning direction is narrower than the width of the light beam incident on the original platen glass surface from the light source, and from the light source. 3. The image reading apparatus according to claim 1, wherein the width is narrower than the width of the light beam reflected by the reflecting member and incident on the platen glass surface. 4. The image reading apparatus according to claim 1, wherein the second opening is formed on a lower surface of the original platen glass. The image reading apparatus according to claim 1, wherein the second opening is formed in a black resin sheet. 6. The image reading apparatus according to claim 1, wherein the second opening is formed in a black felt material. The image reading apparatus according to claim 1, wherein the second opening irradiates a light beam from the light source only on a reading area of a document surface. An original platen glass on which an original is placed, condensing means for condensing a light beam onto a reading area on the original surface placed on the original table glass, and reflected light of the original surface collected by the condensing means is imaged Reading means for reading information, and the light collecting means includes a light source, an inner member including the light source and having a first opening through which a light beam emitted from the light source passes, and the first member An image reading apparatus comprising: a reflecting member that reflects a part of a light beam that has passed through an opening; and a shielding member having a slit between the original table glass and the light source. 9. The image reading apparatus according to claim 8, wherein the light shielding member has a black surface on the light source side. 9. The image reading apparatus according to claim 8, wherein the shielding member is black on both upper and lower surfaces.

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