JP2005051438A - Image processing method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the degradation of a read image in the vicinity of the through-hole of an original manuscript when an image is read by making the longitudinal direction of a photoelectric transducer and that of the original manuscript orthogonal, and to improve the reading performance of the original manuscript image. <P>SOLUTION: The image is read by preventing the light from a light source 1709 from reaching the linear photoelectric transducer 1704 via the through-hole P of a film F. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention forms an image in an image reading area of a sheet having translucency, is located in a non-image reading area of the sheet, is located on both sides in the width direction of the sheet, and is arranged in a row in the length direction. The present invention relates to an image processing method and apparatus for reading an image of a document having a plurality of feed through holes.
[0002]
[Prior art]
In general, an image reading apparatus (hereinafter, referred to as an image scanner) irradiates a document placed on a platen glass with light, and uses reflected light or transmitted light obtained by using a lens or the like to generate an image. An image is read by forming an image on a sensor or a photoreceptor.
[0003]
In recent years, a contact image sensor (hereinafter referred to as CIS) using a rod lens array is often used in a consumer image scanner in order to reduce the size of the image scanner.
[0004]
Further, an image scanner equipped with a CIS capable of reading an image of a film by irradiating light from above the film onto a translucent document (hereinafter referred to as film) on a platen glass. Has been developed (see Patent Document 1).
[0005]
Hereinafter, a method of reading an image on a film with an image scanner equipped with a conventional CIS will be described with reference to FIGS.
[0006]
FIG. 17 is a side view with a part cut away showing a schematic configuration of a conventional image scanner, FIG. 18 is a plan view showing a schematic configuration of a film reading apparatus (hereinafter referred to as FAU), and FIG. FIG. 20 is a side view showing a schematic configuration of the light source portion of the FAU, FIG. 22 is a cross-sectional view taken along the line CC in FIG. 21, and FIG. 23 is a view of the FAU. FIG. 24 is a plan view showing a part of a film.
[0007]
In FIG. 17, reference numeral 1700 denotes an image scanner, which has a CIS 1702 that scans along the platen glass 1701 in order to read a film (original) F placed on the platen glass 1701. A reflection original light source (not shown), a rod lens array (imaging means) 1703, and a linear photoelectric conversion element 1704 are provided.
[0008]
17 to 20, reference numeral 1705 denotes an FAU, which includes a light source unit 1706 and a film holder 1707. As shown in FIGS. 21 to 23, the light source unit 1706 includes a light source 1709 provided inside the housing 1708 and a diffusion plate 1710 provided so as to close the lower surface opening of the housing 1708. ing. The diffusing plate diffuses light from the light source 1709 uniformly into the film F.
[0009]
The film holder 1707 is a positioning member for positioning the film F and the light source unit 1706. As shown in FIG. 18, the film holder 1707 has an opening 1707a for guiding the light from the light source 1709 to the line-shaped photoelectric conversion element 1704. , Provided at the center in the width direction and along the longitudinal direction.
[0010]
When reading the film F, as shown in FIG. 17, a film holder 1707 is placed on the platen glass 1701 of the image scanner 1700, and the film F is placed on the film holder 1707. A light source unit 1706 is disposed on the film holder 1707, and the film F is irradiated with light from the light source unit 1706, and the CIS 1702 is scanned along the platen glass 1701 to form a line shape through the rod lens array 1703. An image formed on the photoelectric conversion element 1704 is read.
[0011]
As shown in FIG. 24, the film F has a read image area Fa (two-dot chain line portion in FIG. 24) and a non-read image area Fb. In the case of a 35 mm film, the film F is located in the non-read image area Fb and is a film. A plurality of through-holes (hereinafter referred to as perforations) P are provided in a row in the longitudinal direction of the film F and located on both sides in the width direction of F. The perforation P is engaged with a feeding gear provided in the camera so that the film F is sequentially fed.
[0012]
Here, the mutual interval between the perforation P on one side in the width direction (short side direction) and the perforation P on the other side of the film F is defined as l.
[0013]
Further, the read image may be deteriorated due to the positional relationship between the film F and the linear photoelectric conversion element 1704.
[0014]
Deterioration of the read image will be described with reference to FIGS.
[0015]
25 is a schematic plan view of the image scanner 1700 when the longitudinal direction of the film F and the longitudinal direction of the line-shaped photoelectric conversion element 1704 are matched, FIG. 26 is an enlarged view of the film F portion of FIG. 25, and FIG. FIG. 28 is a schematic plan view of the image scanner 1700 when the longitudinal direction of the film F and the longitudinal direction of the linear photoelectric conversion element 1704 are orthogonal to each other, and FIG. 29 is a film F portion of FIG. FIG. 30 is an EE cross-sectional view of FIG.
[0016]
When the image of the film F is read by matching the longitudinal direction of the film F and the longitudinal direction of the line-shaped photoelectric conversion element 1704 (two-dot chain line 2500 in FIGS. 25 and 26), the light source 1709 including the vicinity of the read image area Fa is also included. As shown in FIG. 27, the light from the light uniformly passes through the film F and reaches the line-shaped photoelectric conversion element 1704, so that the read image is not adversely affected.
[0017]
However, when an image on the film F is read with the longitudinal direction of the film F and the longitudinal direction of the linear photoelectric conversion element 1704 orthogonal to each other (two-dot chain line 2800 in FIGS. 28 and 29), the light from the light source 1709 is As shown in FIG. 30, the diffused light that directly enters from the perforation P of the non-read image region Fb and enters the rod lens array 1703 or the like when the high-level direct light enters the rod lens array 1703, etc. As a result, the read image near the perforation P may be adversely affected.
[0018]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 06-152878
[Problems to be solved by the invention]
However, although the line-shaped photoelectric conversion element 1704 used in the conventional consumer image scanner 1700 has a total length of about 220 mm, it is not composed of a single sensor chip, but a sensor chip of about 30 mm to 40 mm. A plurality of lines are arranged side by side.
[0020]
Therefore, when a plurality of sensor chips are arranged in a line, there is a problem in that each sensor chip does not become a straight line on the micron order due to the problem of assembly accuracy, and image degradation called a step difference between chips occurs. Further, when reading an image on the film F, the image is often read at a reading magnification of 100% (original size) or more, and there is a problem that image deterioration due to a step difference between chips is emphasized.
[0021]
On the other hand, as a method of eliminating image degradation due to a step difference between chips at the time of image reading of a film, a method of orthogonally crossing the longitudinal direction of the image sensor and the longitudinal direction of the film has been proposed. When the longitudinal direction is orthogonal, there is a problem that the image is deteriorated due to the influence of direct light from the perforation P.
[0022]
SUMMARY An advantage of some aspects of the invention is that it prevents deterioration of a read image in the vicinity of a perforation of a document and improves a document image reading performance.
[0023]
[Means for Solving the Problems]
In order to achieve the above object, an image processing method of the present invention forms an image in an image reading area of a translucent sheet and is positioned in a non-image reading area of the sheet and on both sides in the width direction of the sheet. A holding means for holding a document having a plurality of through-holes positioned and in a length direction on a document table having translucency; and illuminating the document placed and held on the document table from above An image reading method for reading an image by an image reading apparatus comprising: an illuminating unit that performs an image forming unit that forms an image on a photoelectric conversion element of transmitted light from the document irradiated by the illuminating unit, the illuminating unit The image is read so as to prevent the light from the light from reaching the photoelectric conversion element through the through hole of the document.
[0024]
In order to achieve the above object, an image processing apparatus according to the present invention forms an image in an image reading area of a translucent sheet and is positioned in a non-image reading area of the sheet, and the width direction of the sheet A holding means for holding a document having a plurality of through holes located on both sides and extending in the length direction on a document table having translucency, and illuminating the document held on the document table from above Illuminating means for diffusing the light from the illuminating means uniformly to the original, and the light transmitted through the original illuminated by the illuminating means through the diffusion plate is coupled to the photoelectric conversion element. An image reading apparatus having an image forming means for forming an image, wherein a prevention means for preventing light from the illumination means from reaching the photoelectric conversion element through a through hole of the document is provided. .
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an image reading method and apparatus according to the present invention will be described with reference to FIGS.
[0026]
The gist of the present invention is that the light from the illumination means is prevented from reaching the photoelectric conversion element through the through hole of the document.
[0027]
[First Embodiment]
First, a first embodiment of the present invention will be described with reference to FIG.
[0028]
FIG. 1 is a cross-sectional view showing a main configuration of the image reading apparatus according to the first embodiment. In FIG. 1, the same parts as those in FIGS. It is.
[0029]
In FIG. 1, the original film F is drawn exaggeratedly. Further, in FIG. 1, there is a gap between the film F and the lower surface of the light source unit 1706, but actually, the film F and the lower surface of the light source unit 1706 are arranged on the film holder 1707 in a state of being in close contact with each other. .
[0030]
In the present embodiment, as shown in FIG. 1, the width L1 of the diffusion plate 1710 is set to be smaller than the distance l between the perforations P on both sides in the width direction of the film F (L1 <l). The perforations P and P of the film F are covered with a part 1708a on the bottom surface side of the body 1708, so that the light from the light source 1709 directly passes through the perforations P and P of the film F to form a linear photoelectric conversion element 1704. Therefore, the read image does not deteriorate.
[0031]
[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
[0032]
In the second embodiment, the width L of the diffusion plate 1710 is made to correspond to the case where the perforations P on both sides in the width direction of the film F are larger than the distance l between them (L> l), and is made of a plate material. A case where the light blocking member covers the perforations P and P of the film F so that the light from the light source 1709 does not directly reach the linear photoelectric conversion element 1704 via the perforation P of the film F is shown.
[0033]
2 is a side view showing the configuration of the light source unit in the image reading apparatus according to the second embodiment, FIG. 3 is a view as seen from the arrow G in FIG. 2, and FIG. 4 is a view as seen from the arrow H in FIG. In the figure, the same parts as those in FIGS. 17 to 27 of the conventional example described above are denoted by the same reference numerals.
[0034]
FIG. 5 is a plan view showing a configuration of a light shielding member used in the image reading apparatus according to the second embodiment, and FIG. 6 is a sectional view taken along line JJ in FIG.
[0035]
In FIGS. 5 and 6, reference numeral 601 denotes a light shielding member made of a rectangular plate, and the planar shape thereof is set to be the same as the planar shape of the housing 1708 of the light source unit 1706. The light shielding member 601 has a rectangular frame shape having a rectangular opening 601a at the center thereof. The width L2 of the opening 601a is set to be smaller than the distance l between the perforations P on both sides of the film F in the width direction (L2 <l).
[0036]
FIG. 7 is a side view of the light source unit 1706 with the light shielding member 601 attached to the lower surface of the housing 1708, and FIG. 8 is a view taken in the direction of the arrow K in FIG. Are given the same reference numerals.
[0037]
As shown in FIGS. 7 and 8, by attaching the light shielding member 601 to the lower surface of the casing 1708 of the light source unit 1706, the diffusion plate 1710 has a perforation P on both sides in the width direction of the film F and a distance l between the perforations P, P. It will be in the state exposed from the opening part 601a of the small width L2.
[0038]
FIG. 9 is a cross-sectional view showing the main configuration of the image reading apparatus according to the second embodiment. In FIG. 9, the same parts as those in FIGS. 17 to 27 and FIGS. The same reference numerals are given.
[0039]
In FIG. 9, the film F as an original is drawn exaggeratedly. In FIG. 9, there is a gap between the film F and the light shielding member 601 on the lower surface of the light source unit 1706, but actually, the film F and the light shielding member 601 are arranged in the film holder 1707 in close contact with each other. Is done.
[0040]
As shown in FIG. 9, the light shielding member 601 is interposed between the film F and the diffusion plate 1710, and the perforations P and P on both sides in the width direction of the film F are covered with the light shielding member 601. .
[0041]
In the present embodiment, as shown in FIG. 9, a light shielding member 601 is interposed between the film F and the diffusion plate 1710, and the perforations P and P on both sides in the width direction of the film F are covered by the light shielding member 601. Thus, the light from the light source 1709 does not reach the linear photoelectric conversion element 1704 directly via the perforations P and P of the film F, so that the read image does not deteriorate.
[0042]
[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
[0043]
In the third embodiment, as in the second embodiment described above, the case where the width L of the diffusion plate 1710 is greater than the distance l between the perforations P and P on both sides in the width direction of the film F (L> l). The perforations P and P of the film F are covered with a holding portion that holds the diffusion plate 1710, and thus the light from the light source 1709 is directly connected to the linear photoelectric conversion element 1704 via the perforations P of the film F. The case where it is made not to reach is shown.
[0044]
FIG. 10 is a cross-sectional view showing the main configuration of an image reading apparatus according to the third embodiment. In FIG. 10, the same parts as those in FIGS. It is.
[0045]
In FIG. 10, the original film F is drawn exaggeratedly. In FIG. 10, there is a gap between the film F and the lower surface of the light source unit 1706, but actually, the film F and the lower surface of the light source unit 1706 are placed in close contact with each other on the film holder 1707. .
[0046]
As shown in FIG. 10, both side portions of the diffusion plate 1710 are located on both sides of the lower surface of the housing 1708 of the light source unit 1706, and holding portions 1708a and 1708b provided to face each other with a gap L3 toward the inside. Retained on top of it. The spacing L3 between the holding portions 1708a and 1708b is set to be smaller than the distance l between the perforations P and P on both sides in the width direction of the film F (L3 <l) as shown in FIG.
[0047]
As shown in FIG. 10, the perforations P and P on both sides in the width direction of the film F are covered with holding portions 1708 a and 1708 b provided on both lower surfaces of the housing 1708 of the light source unit 1706.
[0048]
In this embodiment, as shown in FIG. 10, perforations P on both sides of the film F in the width direction are provided by holding portions 1708a and 1708b provided on both sides of the lower surface of the housing 1708 of the light source portion 1706 to hold the diffusion plate 1710. , P is covered, so that the light from the light source 1709 does not reach the linear photoelectric conversion elements 1704 directly through the perforations P, P of the film F, and the read image does not deteriorate.
[0049]
According to the present embodiment, the holders 1708a and 1708b that hold the diffusion plate 1710 prevent light from the light source 1709 from reaching the linear photoelectric conversion element 1704 directly through the perforations P and P of the film F. Therefore, the deterioration of the read image can be prevented without providing a special prevention member such as the light shielding member in the second embodiment described above.
[0050]
[Fourth embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIGS.
[0051]
In the fourth embodiment, the width L of the diffusion plate 1710 is larger than the distance l between the perforations P and P on both sides in the width direction of the film F (L> l) as in the second and third embodiments described above. ) Covers the perforations P and P of the film F with a light-shielding member made of a sheet material, so that the light from the light source 1709 directly undergoes linear photoelectric conversion via the perforation P of the film F. A case where the element 1704 is not reached is shown.
[0052]
FIG. 11 is a plan view illustrating a configuration of a sheet-like light shielding member used in the image reading apparatus according to the fourth embodiment, and FIG. 12 is a cross-sectional view taken along line MM in FIG.
[0053]
11 and 12, reference numeral 1101 denotes a light shielding member made of a rectangular sheet material, and the planar shape thereof is set to a similar shape slightly smaller than the planar shape of the housing 1708 of the light source unit 1706. The light shielding member 1101 has a rectangular frame shape having a rectangular opening 1101a at the center thereof. The width L4 of the opening 1101a is set to be smaller than the distance l between the perforations P on both sides of the film F in the width direction (L4 <l).
[0054]
FIG. 13 is a cross-sectional view of a main part of an image reading apparatus according to the fourth embodiment. In FIG. 13, the same parts as those in FIGS.
[0055]
In FIG. 13, the original film F is drawn exaggeratedly. In FIG. 13, there are gaps between the lower surface of the light source unit 1706 and the light shielding member 1101 and between the film F and the light shielding member 1101, but actually, the lower surface of the light source unit 1706 and the light shielding member 1101 and The film F and the light shielding member 1101 are disposed on the film holder 1707 in a state of being in close contact with each other.
[0056]
As shown in FIG. 13, when reading the image of the film F, the light shielding member 1101 is used by being interposed between the diffusion plate 1710 which is the lower surface of the light source unit 1706 and the film F.
[0057]
As shown in FIG. 13, the light shielding member 1101 is interposed between the film F and the diffusion plate 1710, and the perforations P and P on both sides in the width direction of the film F are covered with the light shielding member 1101. .
[0058]
In the present embodiment, as shown in FIG. 13, a light shielding member 1101 is interposed between the film F and the diffusion plate 1710, and the perforations P and P on both sides in the width direction of the film F are covered with the light shielding member 1101. Thus, the light from the light source 1709 does not reach the linear photoelectric conversion element 1704 directly via the perforations P and P of the film F, so that the read image does not deteriorate.
[0059]
In the present embodiment, the same effect can be obtained even if the light shielding member 1101 is interposed below the film F as shown in FIG.
[0060]
In FIG. 14, the same parts as those in FIG. 13 are denoted by the same reference numerals.
[0061]
[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described with reference to FIGS.
[0062]
In the fifth embodiment, as in the second to fourth embodiments described above, the width L of the diffusion plate 1710 is greater than the distance l between the perforations P, P on both sides in the width direction of the film F (L> l). In this case, a part of the film holder covers the perforations P and P of the film F so that the light from the light source 1709 directly passes through the perforations P of the film F to form a linear photoelectric conversion element 1704. The case where it is made not to reach is shown.
[0063]
15 is a plan view showing the configuration of the main part of an image reading apparatus according to the fifth embodiment, and FIG. 16 is a cross-sectional view taken along line NN in FIG. 15. In both figures, FIGS. The same parts as those in FIG.
[0064]
In FIG. 16, the original film F is drawn exaggeratedly. In FIG. 16, there is a gap between the lower surface of the light source unit 1706 and the holding units 1707 b and 1707 c of the film holder 1707, but actually the lower surface of the light source unit 1706 (the lower surface of the diffusion plate 1701) is the holding unit. The film holder 1707 is placed in close contact with 1707b and 1707c.
[0065]
As shown in FIGS. 15 and 16, holding portions 1707 b and 1707 c are provided so as to be located on both sides in the width direction (short direction) of the film holder 1707 and to face each other with a gap L <b> 5 toward the inside. . The mutual interval L5 between the holding portions 1707b and 1707c is set smaller than the distance l between the perforations P and P on both sides in the width direction of the film F (L5 <l) as shown in FIG.
[0066]
As shown in FIG. 16, the film F is held by the film holder 1707 while being inserted between the lower wall of the film holder 1707 and the holding portions 1707b and 1707c. In this state, the film F is held by the holding portions 1707b and 1707c. The perforations P, P on both sides in the width direction of the film F are covered.
[0067]
In this embodiment, as shown in FIG. 16, perforations P and P on both sides in the width direction of the film F are covered by holding portions 1707 b and 1707 c provided on both upper sides of the film holder 1707 in order to hold the film F. As a result, the light from the light source 1709 does not reach the linear photoelectric conversion element 1704 directly via the perforations P and P of the film F, so that the read image does not deteriorate.
[0068]
According to the present embodiment, the holders 1707b and 1707c that hold the film F prevent light from the light source 1709 from reaching the linear photoelectric conversion element 1704 directly via the perforations P and P of the film F. Since the configuration is adopted, it is possible to prevent deterioration of the read image without specially providing a prevention dedicated member such as the light shielding member in the second embodiment described above.
[0069]
In the drawings described above, the opening 1707a of the film holder 1707 is shown smaller than the width of the film F. However, the opening of the film F is slightly larger than the film F, and the end of the film F directly contacts the platen glass 1701. It can also be set as the structure which touches.
[0070]
The above is the description of the embodiments of the present invention. However, the present invention is not limited to these embodiments, and the functions shown in the claims or the functions of the embodiments can be achieved. Any configuration is applicable.
[0071]
【The invention's effect】
According to the present invention, since the light from the illumination means is prevented from reaching the photoelectric conversion element through the through hole of the original, the longitudinal direction of the photoelectric conversion element and the longitudinal direction of the original are orthogonal to each other. Thus, when reading an image, it is possible to prevent deterioration of the read image in the vicinity of the through hole of the document and to improve the reading performance of the document image.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of an image reading apparatus according to a first embodiment of the present invention.
FIG. 2 is a side view illustrating a configuration of a light source unit of an image reading apparatus according to a second embodiment of the present invention.
FIG. 3 is a view on arrow G in FIG. 2;
4 is a view taken in the direction of arrow H in FIG.
FIG. 5 is a plan view of a light shielding member used in an image reading apparatus according to a second embodiment of the present invention.
6 is a cross-sectional view taken along line JJ in FIG.
FIG. 7 is a side view of a state in which a light shielding member is attached to a light source unit of an image reading apparatus according to a second embodiment of the present invention.
8 is a view taken in the direction of arrow K in FIG.
FIG. 9 is a cross-sectional view of a main part of an image reading apparatus according to a second embodiment of the present invention.
FIG. 10 is a cross-sectional view of main parts of an image reading apparatus according to a third embodiment of the present invention.
FIG. 11 is a plan view of a light shielding member used in an image reading apparatus according to a fourth embodiment of the present invention.
12 is a cross-sectional view taken along line MM in FIG.
FIG. 13 is a cross-sectional view of main parts of an image reading apparatus according to a fourth embodiment of the present invention.
FIG. 14 is a cross-sectional view of a main part in a state different from that of FIG.
FIG. 15 is a plan view of an essential part of an image reading apparatus according to a fifth embodiment of the present invention.
FIG. 16 is a cross-sectional view of main parts of an image reading apparatus according to a fifth embodiment of the present invention.
FIG. 17 is a side view illustrating a configuration of a conventional image reading apparatus.
FIG. 18 is a plan view showing a configuration of a film reading apparatus of a conventional image reading apparatus.
FIG. 19 is a view on arrow A of FIG.
20 is a view on arrow B in FIG. 18;
FIG. 21 is a side sectional view showing a configuration of a light source unit in a conventional image reading apparatus.
22 is a cross-sectional view taken along the line CC of FIG. 21. FIG.
FIG. 23 is a bottom view illustrating a configuration of a light source unit in a conventional image reading apparatus.
FIG. 24 is a partially enlarged plan view of a film which is a document read by a conventional image reading apparatus.
FIG. 25 is a plan view of a main part in a state in which the longitudinal direction of the film and the longitudinal direction of the line-shaped photoelectric conversion element are matched in the conventional image reading apparatus.
26 is an enlarged view of the film portion of FIG. 25. FIG.
27 is a sectional view taken along the line DD in FIG. 26. FIG.
FIG. 28 is a plan view of a principal part in a state where the longitudinal direction of a film and the longitudinal direction of a linear photoelectric conversion element are orthogonal to each other in a conventional image reading apparatus.
29 is an enlarged view of the film portion of FIG. 28. FIG.
30 is a cross-sectional view taken along line EE of FIG. 29. FIG.
[Explanation of symbols]
F film (original)
Fa Read image area Fb Non-read image area P Perforation (through hole)
601 Light shielding member 601a Opening (translucent part)
1101 Light shielding member 1101a Opening (translucent part)
1700 Image scanner (image reading device)
1701 Document glass (translucent document table)
1702 CIS
1703 Rod lens array (imaging means)
1704 Line-shaped photoelectric conversion element (photoelectric conversion element)
1705 Film reader (FAU)
1706 Light source part 1707 Film holder 1707a Opening part 1707b Holding part 1707c Holding part 1708 Case 1708a Part 1709 on the bottom side of the case Light source 1710 Diffuser

Claims (8)

An image is formed in an image reading area of a light-transmitting sheet, and a plurality of through holes are provided in the non-image reading area of the sheet and on both sides in the width direction of the sheet and extending in the length direction. Holding means for holding the original on a translucent original table, illumination means for illuminating the original held on the original table from above, and light transmitted through the original irradiated by the illumination means An image reading method for reading an image by an image reading apparatus comprising an image forming means for forming an image on a photoelectric conversion element,
An image reading method, wherein an image is read so as to prevent light from the illuminating means from reaching the photoelectric conversion element through a through hole of the document. An image is formed in an image reading area of a light-transmitting sheet, and a plurality of through holes are provided in the non-image reading area of the sheet and on both sides in the width direction of the sheet and extending in the length direction. Holding means for holding the original on a translucent original table, illuminating means for illuminating the original held on the original table from above, and uniformly diffusing light from the illuminating means to the original An image reading apparatus comprising: a diffusion plate for image formation; and an image forming unit that forms an image on a photoelectric conversion element of light transmitted through the original irradiated through the diffusion plate by the illumination unit.
An image reading apparatus comprising: a preventing unit that prevents light from the illuminating unit from reaching the photoelectric conversion element through a through hole of the document. The prevention means sets the width of the diffusion plate to be shorter than the distance between the through-hole rows in the width direction of the document, so that the light from the illumination means passes through the through-hole of the document and the photoelectric conversion element The image reading apparatus according to claim 2, wherein the image reading apparatus is configured to prevent reaching the position. The prevention means includes a light shielding member having a light transmission portion having a width shorter than a distance between the through hole rows in the width direction of the document, so that light from the illumination means is transmitted through the through holes of the document. The image reading apparatus according to claim 2, wherein the image reading apparatus is configured to prevent the photoelectric conversion element from reaching the photoelectric conversion element. The image reading apparatus according to claim 4, wherein the light shielding member is provided between the diffusion plate and the original. The image reading apparatus according to claim 4, wherein the light shielding member is provided under the document. The preventing means prevents the light from the illuminating means from reaching the photoelectric conversion element through the through-hole of the document when a holding portion for holding the diffusion plate covers the through-hole of the document. The image reading apparatus according to claim 2, wherein the image reading apparatus is configured to prevent it. The preventing means prevents a light from the illuminating means from reaching the photoelectric conversion element through the through-hole of the document when a part of the holding unit covers the through-hole of the document. The image reading apparatus according to claim 2, wherein the image reading apparatus is configured.

Images