Optical device, image reading device, and image forming device

Abstract

The present application provides an optical device, an image reading device and an image forming device, which can make the focal depth of the obtained equal upright real image deeper compared with the case without using the present structure. The optical device comprises: a lens body having a plurality of lenses arranged in parallel with their optical axes, and an intermediate imaging plane for forming an equal upright real image formed in the optical path; a light shielding body arranged opposite to the light incident surface in the lens body, and having a transmission part located on the optical axes of the plurality of lenses and transmitting light, and a light shielding part located on positions other than the optical axes of the plurality of lenses and blocking the passage of light; and a limiting body arranged opposite to the light incident surface in the light shielding body, and having an opening narrower than the transmission part and limiting a part of the light towards the transmission part.

Description

Technical Field

[0001] This invention relates to an optical device, an image reading device, and an image forming device. Background Technology

[0002] Patent Document 1 discloses a lens array unit in which a first lens array and a second lens array are arranged to overlap each other with each lens facing each other, and a light-shielding member made of black resin with light-shielding properties and having a plurality of through holes is arranged to overlap with the first lens array with the plurality of through holes being the front side of the first lens surface of each first lens of the first lens array. The first lens array is integrally formed by molding a plurality of first lenses and a first retainer portion holding the plurality of first lenses with light-transmitting resin, and the second lens array is integrally formed by molding a plurality of second lenses and a second retainer portion holding the plurality of second lenses with light-transmitting resin.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2001-352429

[0004] For a lens body having a plurality of lenses arranged in a parallel manner along their optical axes, a light-shielding body is sometimes provided to block a portion of the light passing through the lenses, for example, to suppress stray light. Furthermore, as such a light-shielding body, a structure is known to have a through-hole provided at a position opposite each lens to allow light to pass through. However, simply providing a through-hole in the light-shielding body sometimes results in a shallower depth of focus for the upright real image obtained by light passing through the through-hole of the light-shielding body and the lens body, which is of equal magnification. Summary of the Invention

[0005] The purpose of this invention is to increase the depth of focus of the obtained upright real image by an equal multiple compared to cases without this structure.

[0006] The invention described in Scheme 1 includes: a lens body having a plurality of lenses arranged in parallel with their respective optical axes, and an intermediate imaging surface for forming an upright real image of equal magnification formed in the optical path; a light shield being disposed opposite to the incident surface of light in the lens body, and having a transmissive portion located on the optical axis of the plurality of lenses and allowing light to pass through, and a light shielding portion located at a position other than the optical axis of the plurality of lenses and blocking the passage of light; and a limiting body being disposed opposite to the incident surface of light in the light shielding body, and having an opening narrower than the transmissive portion and limiting a portion of the light toward the transmissive portion.

[0007] The invention described in Scheme 2 is the optical device described in Scheme 1, characterized in that the light-shielding body has: a base disposed on the side of the plurality of lenses along the direction in which the plurality of lenses are arranged, i.e., the arrangement direction; and a plurality of protrusions protruding from the base in a cross direction intersecting the arrangement direction between the lenses of the plurality of lenses, and the limiting body covers a portion of the area in the light-shielding body where the base and the plurality of protrusions are not present.

[0008] The invention described in Scheme 3 is the optical device described in Scheme 2, characterized in that the plurality of lenses are arranged in a first column and a second column along the arrangement direction, and the light-shielding body has: a first light-shielding body having: a first base disposed on the side of the lenses in the first column along the arrangement direction; and a plurality of first protrusions protruding from the first base toward the crossing direction between the lenses in the first column; and a second light-shielding body having: a second base disposed on the side of the lenses in the second column and on the side opposite to the first base along the arrangement direction, separated by the lenses in the first column and the lenses in the second column; and a plurality of second protrusions protruding from the second base toward the crossing direction between the lenses in the second column, and the limiting body covers a portion of the area in the light-shielding body where the first light-shielding body and the second light-shielding body are not present.

[0009] The invention described in Scheme 4 is the optical device described in Scheme 3, characterized in that the limiting body covers the portion facing the plurality of first protrusions in the first light-shielding body and the plurality of second protrusions in the second light-shielding body along the arrangement direction.

[0010] The invention described in Scheme 5 is the optical device described in Scheme 1, characterized in that the light-shielding body has: the light-shielding portion, which covers the portion of each of the plurality of lenses other than the incident surface; and the transmission portion, which is formed by a plurality of windows disposed on the light-shielding portion, and the limiting body covers the inner periphery of the light-shielding portion in the light-shielding body and the plurality of windows forming the light-shielding portion.

[0011] The invention described in Scheme 6 is the optical device described in Scheme 5, characterized in that an opening corresponding to each of the plurality of lenses is provided on the limiting body, and the diameter of the opening provided on the limiting body is smaller than the diameter of the window provided on the light-shielding body.

[0012] The invention described in Scheme 7 is the optical device described in Scheme 1, characterized in that the lens body comprises: a first lens body having a plurality of first lenses arranged in parallel with their respective optical axes, and disposed opposite to the light-emitting surface in the light-shielding body, and light transmitted through the plurality of first lenses forming the intermediate imaging surface; and a second lens body having a plurality of second lenses arranged in parallel with their respective optical axes, and disposed opposite to the light-emitting surface in the first lens body, and light passing through the first lens body and forming the intermediate imaging surface is incident therein, the limiting body limiting the light incident on the peripheral side of each of the plurality of first lenses disposed on the first lens body.

[0013] The invention described in Scheme 8 is an image reading device comprising: an illumination unit that illuminates an original document with light; a lens body having a plurality of lenses arranged in parallel with their respective optical axes to allow light reflected from the original document to pass through; a light shield disposed opposite to the incident surface of light in the lens body, and having a transmissive portion located on the optical axis of the plurality of lenses to allow light to pass through and a light shield located at a position other than the optical axis of the plurality of lenses to block the passage of light; a limiting body disposed opposite to the incident surface of light in the light shield, and having an opening narrower than the transmissive portion to limit a portion of the light directed toward the transmissive portion; and a light receiving unit that receives light passing through the plurality of lenses.

[0014] The invention described in Scheme 9 is an image forming apparatus, characterized by comprising: an illumination unit that illuminates a document with light; a lens body having a plurality of lenses arranged in parallel with their respective optical axes to allow light reflected from the document to pass through; a light shield disposed opposite to the incident surface of light in the lens body, and having a transmissive portion located on the optical axis of the plurality of lenses to allow light to pass through and a light shield located at a position other than the optical axis of the plurality of lenses to block the passage of light; a limiting body disposed opposite to the incident surface of light in the light shield, and having an opening narrower than the transmissive portion to limit a portion of the light directed toward the transmissive portion; a light receiving unit that receives light passing through the plurality of lenses; and an image forming unit that forms an image based on the light received by the light receiving unit.

[0015] Invention Effects

[0016] According to the first aspect of the present invention, compared with the case where this structure is not used, the depth of focus of the obtained upright real image is increased by an equal multiple.

[0017] According to the second aspect of the present invention, compared with the case where this structure is not used, the depth of focus can be increased and the generation of stray light can be suppressed.

[0018] According to a third aspect of the present invention, in a structure in which the lens is arranged in a plurality of columns and the light-shielding body includes a first light-shielding body and a second light-shielding body, the depth of focus can be increased and the generation of stray light can be suppressed.

[0019] According to the fourth aspect of the present invention, compared with the case where this structure is not used, it is possible to suppress the structure of the limiting body from becoming complicated.

[0020] According to the fifth aspect of the present invention, compared with the case where this structure is not used, the depth of focus can be increased and the generation of stray light can be suppressed.

[0021] According to the sixth aspect of the present invention, in a structure in which an opening corresponding to a plurality of lenses is provided on the limiting body, the depth of focus can be increased and stray light generation can be suppressed.

[0022] According to the seventh aspect of the present invention, in a structure with a plurality of lens bodies, the depth of focus can be increased and stray light generation can be suppressed.

[0023] According to the eighth aspect of the present invention, compared with the case where this structure is not used, the depth of focus of the obtained upright real image of equal size can be increased.

[0024] According to the ninth aspect of the present invention, compared with the case where this structure is not used, the depth of focus of the obtained upright real image of equal size can be increased. Attached Figure Description

[0025] The embodiments of the present invention will be described in detail with reference to the following figures.

[0026] Figure 1 This is a schematic structural diagram of the image forming apparatus applicable to this embodiment;

[0027] Figure 2 This is a schematic structural diagram of the image reading device applicable to this embodiment;

[0028] Figure 3 This is an exploded perspective view of the lens array unit applicable to this embodiment;

[0029] Figure 4 (a) and Figure 4 (b) is a diagram used to illustrate the light-blocking wall;

[0030] Figure 5 (a) and Figure 5 (b) is a diagram illustrating the configuration of the light-shielding wall;

[0031] Figure 6 (a) to Figure 6 (d) is a diagram used to illustrate a variation of the light-shielding film;

[0032] Figure 7 (a) and Figure 7 (b) is a graph showing the simulation results after the shape of the light-shielding film was changed;

[0033] Figure 8 It is a diagram used to illustrate a modified example of the light-shielding wall, and is an exploded perspective view of the lens array unit of the light-shielding wall including the modified example;

[0034] Figure 9 (a) and Figure 9 (b) is a diagram used to illustrate the relationship between the wall penetration holes and the membrane penetration holes in a modified example of the light-shielding wall;

[0035] Figure 10 (a) and Figure 10 (b) is a diagram used to illustrate the relationship between the presence or absence of light-shielding walls and light-shielding films in the lens array unit and the depth of focus;

[0036] Figure 11 (a) and Figure 11 (b) is a diagram used to illustrate the relationship between the wall penetrations and the membrane penetrations in a modified example of the light-shielding film.

[0037] Symbol Explanation

[0038] 1-Original document reading device, 10-Lens array unit, 100-Image forming device, 110-Light-shielding film, 111-Plate surface, 113-Film through hole, 130-Light-shielding wall, 131A-First wall component, 131B-Second wall component, 132-Base, 134-Wall through hole, 135-Optical axis groove, 137-Protrusion, 170-First lens array, 171-First support, 173-First lens, 180-Second lens array, 181-Second support, 183-Second lens. Detailed Implementation

[0039] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the sizes or thicknesses of the parts in the drawings referred to in the following description may sometimes differ from the actual dimensions.

[0040] <Image forming apparatus 100>

[0041] Figure 1 This is a schematic structural diagram of the image forming apparatus 100 applicable to this embodiment.

[0042] like Figure 1As shown, the image forming apparatus 100 includes a document reading device 1 for reading information from a document G, an image forming unit 2 for forming an image on recording paper S based on the information (reading image) from the document read by the document reading device 1, and a paper feeding unit 3 for feeding the recording paper S supplied to the image forming unit 2. In this image forming apparatus 100, the image forming unit 2 and the paper feeding unit 3 are housed inside a main body 101, while the document reading device 1 is disposed above the main body 101. The main body 101 has an discharge receiving unit 102 on its upper surface for discharging and receiving the recording paper S on which the image is formed.

[0043] The document reading device 1 has a housing 103. Furthermore, the document reading device 1 has a light-transmitting document stage 105 for placing the document G on the upper surface of the housing 103, and a document cover 106 covering the document stage 105 and capable of opening and closing the housing 103. The document cover 106 is provided with an automatic document transport unit 107 for transporting the document G to the reading position and discharging the read document G, a document tray 108 for holding the document G transported by the automatic document transport unit 107, and a receiving part 109 for accommodating the document G discharged from the automatic document transport unit 107.

[0044] The image forming unit 2 includes, for example, an image forming unit 20 that forms toner images of yellow (Y), magenta (M), cyan (C), and black (K) using an electrophotographic method; an intermediate transfer unit 26 that transfers the toner images formed by the image forming unit 20 to the recording paper S; and a fixing unit 27 that fixes the toner images transferred from the intermediate transfer unit 26 to the recording paper S. In addition to using an image forming unit that forms images using an electrophotographic method, the image forming unit 2 can also use an image forming unit that forms images using an inkjet method.

[0045] The paper supply unit 3 has a pull-out container 31 capable of holding multiple sheets of recording paper S composed of preset sizes and types, and a delivery device 32 that feeds the recording paper S contained in the container 31 one by one into the transport path. A supply transport path 28 is arranged between the paper supply unit 3 and the image forming unit 2 to transport the recording paper S fed from the paper supply unit 3 to the secondary transfer position.

[0046] Next, the basic operation of the image forming apparatus 100 will be explained.

[0047] First, in the document reading device 1, the user places the original document G on either the document table 105 or the document tray 108. Then, by operating the operation button (not shown), if an instruction to read the original document is received, the reading operation of the original document G begins. That is, the document reading device 1 acquires the reading information of the original document G. Furthermore, the image forming unit 2 performs an image forming operation based on the reading information of the original document G received from the document reading device 1. At this time, recording paper S is fed from the paper supply unit 3 in conjunction with the operation of the image forming unit 2. After the toner image is fixed in the image forming unit 2, the recording paper S is discharged into the receiving unit 102. The above image forming operation is repeated an amount corresponding to the number of original documents G or the number of images formed.

[0048] <Original Manuscript Reading Device 1>

[0049] Figure 2 This is a schematic structural diagram of the original document reading device 1 applicable to this embodiment.

[0050] Next, refer to Figure 2 The original document reading device 1 to which this embodiment is applied will be described. For example... Figure 2 As shown, the document reading device 1 includes a transparent plate 70, a synthetic resin housing 71 supporting the transparent plate 70, and a substrate 72 mounted on the bottom surface of the housing 71. On the surface of the substrate 72 are a plurality of point-shaped light sources 73 arranged in a row at intervals along the main scanning direction (orthogonal to the paper plane), and a plurality of light-receiving elements 74 arranged in the same direction as the plurality of light sources 73. Each light source 73 is, for example, constructed using a light-emitting diode. Each light-receiving element 74 is a device with photoelectric conversion function; if it receives light, it outputs a signal with an output level corresponding to the amount of light received, specifically an image signal. Furthermore, in this embodiment, the plurality of point-shaped light sources 73 is an example of an illumination section, and the plurality of light-receiving elements 74 is an example of a light-receiving section.

[0051] Here, the document reading device 1 includes a lens array unit 10 between the transparent plate 70 and each light receiving element 74. The detailed structure of the lens array unit 10 will be described in detail later; the illustrated lens array unit 10 is disposed within a recess 75 provided in the housing 71. Furthermore, on the surface of the illustrated transparent plate 70, the portion opposite to the lens array unit 10 forms an image reading area La extending along the main scanning direction. Light is irradiated onto this image reading area La from each light source 73.

[0052] In the original document reading device 1, the automatic original document transport unit 107 (reference) reads the original document. Figure 1The original document G, guided onto the surface of the transparent plate 70, is illuminated by light from the light source 73. The reflected light from the original document G travels toward the lens array unit 10. Thus, through the action of the lens array unit 10, a linear image of the original document G in the image reading area La is imaged vertically and at equal magnification onto a plurality of light receiving elements 74. Therefore, a linear image signal corresponding to the image of the original document G is output from the plurality of light receiving elements 74. This reading process is repeatedly performed multiple times as the original document G is transported, for example, along the sub-scanning direction by the pressure roller 77 of the automatic original document transport unit 107.

[0053] Additionally, in the following description, the direction from the image reading area La toward the light receiving element 74 will sometimes be referred to as... Figure 2 The vertical direction is called the optical axis direction. Furthermore, in this embodiment, the main scanning direction is an example of the arrangement direction, and the sub-scanning direction is an example of the intersection direction.

[0054] <Lens Array Unit 10>

[0055] Figure 3 This is an exploded perspective view of the lens array unit 10 applicable to this embodiment.

[0056] Next, refer to Figure 3 The lens array unit 10 to which this embodiment is applied will be described.

[0057] like Figure 3 As shown, the lens array unit 10 includes a light-shielding film 110, a light-shielding wall 130, a first lens array 170, and a second lens array 180. To further explain, in the illustrated example of the lens array unit 10, the light-shielding film 110, the light-shielding wall 130, the first lens array 170, and the second lens array 180 are stacked sequentially and bonded together by an adhesive or the like. Furthermore, when this lens array unit 10 is installed in the document reading device 1, the light-shielding film 110 faces the transparent plate 70, and the second lens array 180 faces the plurality of light-receiving elements 74. The components of the lens array unit 10 will be described below.

[0058] <First lens array 170 and second lens array 180>

[0059] First, the first lens array 170 and the second lens array 180 will be described.

[0060] As examples of lens bodies, the first lens array 170 and the second lens array 180 are each generally rectangular parallelepiped-shaped components. To explain further, the illustrated first lens array 170 and second lens array 180 are a pair of lens components with the same shape.

[0061] As an example of a first lens body, the first lens array 170 has a first support body 171 with a generally cuboid shape and a plurality of first lenses 173 formed on the surface and back surface of the first support body 171. The plurality of first lenses 173 are configured such that their respective optical axes are parallel to each other. In addition, the parallel optical axes of the plurality of first lenses 173 means that as long as each of the first lenses 173 images a linear image of the original document G in the image reading area La onto the plurality of light receiving elements 74 at an upright and equal magnification, not only can the optical axes of the plurality of first lenses 173 be parallel to each other, but there can also be an angular offset between them. Furthermore, the plurality of first lenses 173 are arranged in a first column R71 and a second column R72 along the main scanning direction. Here, the plurality of first lenses 173 are arranged in a staggered pattern. That is, the first lenses 173 constituting the first column R71 and the first lenses 173 constituting the second column R72 are offset from each other in the main scanning direction. Furthermore, the first lens 173 in the first column R71 is arranged at a predetermined interval, i.e., a spacing. And the first lens 173 in the second column R72 is arranged at the same interval as in the first column R71. Moreover, in Figure 3 In the first lens array 170 shown, the surface facing the upper side of the figure becomes the incident surface of the light in the first lens array 170, and the surface facing the lower side of the figure becomes the exit surface of the light in the first lens array 170.

[0062] The second lens array 180, as an example of a second lens body, has a second support 181 with a generally cuboid shape and a plurality of second lenses 183 formed on the surface and back surface of the second support 181. The plurality of second lenses 183 are configured such that their respective optical axes are continuous. Furthermore, the parallel optical axes of the plurality of second lenses 183 mean that as long as each of the second lenses 183 images a linear image of the original document G in the image reading area La at an upright magnification onto the plurality of light receiving elements 74, not only can the optical axes of the plurality of second lenses 183 be parallel, but there can also be an angular offset between them. Moreover, the plurality of second lenses 183 are arranged in a first column R81 and a second column R82 along the main scanning direction. Here, the plurality of second lenses 183 are arranged in a staggered pattern. That is, the second lenses 183 constituting the first column R81 and the second lenses 183 constituting the second column R82 are offset from each other in the main scanning direction. Furthermore, the second lenses 183 in the first column R81 are arranged at a predetermined interval. And the second lenses 183 in the second column R82 are arranged at the same interval as in the first column R81. Moreover, in Figure 3 In the second lens array 180 shown, the surface facing the upper side of the figure becomes the incident surface of the light in the second lens array 180, and the surface facing the lower side of the figure becomes the exit surface of the light in the second lens array 180.

[0063] In the illustrated example, the first lens array 170 and the second lens array 180 are arranged such that the first lens 173 and the second lens 183 are respectively opposite to each other. That is, the exit surface of each first lens 173 faces the incident surface of each second lens 183. To explain further, they are aligned such that the optical axis of the first lens 173 coincides with the optical axis of the second lens 183. Furthermore, the first lens array 170 and the second lens array 180 are each formed integrally, for example, by injection molding using a light-transmitting optical resin. In the following description, when it is not necessary to distinguish between the optical axis of the first lens 173 and the optical axis of the second lens 183, they are sometimes simply referred to as the "optical axis of the first lens 173".

[0064] Furthermore, in the illustrated example, an intermediate imaging surface is formed between the first lens array 170 and the second lens array 180; in other words, it is located in the optical path between the light exit surface of the first lens array 170 and the light incident surface of the second lens array 180. Moreover, by forming an intermediate imaging surface in this region, light incident from the incident surface side of the first lens array 170 travels through the exit surface of the first lens array 170 and the incident surface of the second lens array 180, forming an upright real image of equal magnification on the exit surface side of the second lens array 180.

[0065] In addition, Figure 2 In the image, the light exiting surface of the first lens array 170 is depicted to be almost in contact with the light incident surface of the second lens array 180, but in reality, there is a space between them. Moreover, the aforementioned intermediate imaging surface is formed within this space.

[0066] <Light-shielding film 110>

[0067] Next, the light-shielding film 110 will be described. The light-shielding film 110 is a thin plate component in the shape of a long strip.

[0068] As an example of a limiting body, the light-shielding film 110 has a plate surface 111 that is generally rectangular in shape when viewed from above. A plurality of film through-holes 113 are formed on this plate surface 111. In this example, each film through-hole 113, as an example of an opening, is generally circular. Furthermore, the position of each film through-hole 113 corresponds to the first lens 173 and the second lens 183. That is, each film through-hole 113 is formed at a position through which the optical axis of the first lens 173 passes. Furthermore, the film through-holes 113 are arranged in a first column R11 and a second column R12 along the main scanning direction. To further explain, each film through-hole 113 corresponds to each of the optical axes (each optical axis) of the first lens 173. Moreover, in Figure 3 In the light-shielding film 110 shown, the surface facing the upper side of the figure becomes the incident surface of light in the light-shielding film 110, and the surface facing the lower side of the figure becomes the exit surface of light in the light-shielding film 110.

[0069] In the illustrated example, the thickness of the light-shielding film 110 is thinner than that of the light-shielding wall 130. That is, the dimension of the light-shielding film 110 in the optical axis direction is smaller than that of the light-shielding wall 130. Furthermore, the light-shielding film 110 is formed, for example, from a resin material (e.g., acrylic resin) mixed with black pigment. This light-shielding film 110 blocks light that does not contribute to the imaging of the first lens 173 and the second lens 183. To further explain, the light-shielding film 110 is disposed in the optical axis direction on the side opposite to the first lens 173 and the second lens 183, separated by the light-shielding wall 130; in other words, it is disposed on the upper surface of the light-shielding wall 130 and blocks a portion of the light that is about to enter the light-shielding wall 130. The relationship between the light-shielding film 110 and the light-shielding wall 130 will be explained in detail later.

[0070] <Light-shielding wall 130>

[0071] Figure 4 (a) and Figure 4 Figure (b) is used to illustrate the light-shielding wall 130. More specifically, Figure 4 (a) is a perspective view of the first wall component 131A. Figure 4 (b) is a top view of the first wall component 131A.

[0072] Figure 5 (a) and Figure 5 Figure (b) is a diagram illustrating the configuration of the light-shielding wall 130. More specifically, Figure 5 (a) is a diagram showing the positional relationship between the first wall component 131A and the second wall component 131B. Figure 5 (b) is Figure 5 (a) is a magnified view in VB.

[0073] Next, refer to Figure 3 , Figure 4 (a) and Figure 4 (b) Figure 5 (a) and Figure 5 (b) describes the light-shielding wall 130.

[0074] like Figure 3 As shown, the light-shielding wall 130, as an example of a light-shielding body, is constructed by arranging two wall components 131, namely the first wall component 131A and the second wall component 131B, each with a generally rectangular shape. To further explain, the light-shielding wall 130 has the first wall component 131A and the second wall component 131B arranged opposite to each other across the optical axis of the first lens 173. Here, the first wall component 131A is an example of a first light-shielding body, and the second wall component 131B is an example of a second light-shielding body.

[0075] As examples of light-shielding parts, the first wall component 131A and the second wall component 131B are formed, for example, from a resin material (e.g., polycarbonate or acrylic resin) mixed with black pigment. Furthermore, in the illustrated example, the first wall component 131A and the second wall component 131B are identical components. Therefore, the detailed structure will be described below using the first wall component 131A as an example.

[0076] like Figure 4 (a) and Figure 4 As shown in (b), the first wall component 131A is a generally cuboid-shaped component. This first wall component 131A is arranged such that its length direction is along the main scanning direction. For example, the length L1 of the first wall component 131A in the main scanning direction is 300 mm, its length L2 in the optical axis direction is 5 mm, and its length L3 in the sub-scanning direction is 2 mm. The first wall component 131A has a surface with its normal along the sub-scanning direction, namely a first side surface 133. Furthermore, this first side surface 133 can be understood as being located within the first wall component 131A and adjacent to the second wall component 131B (see reference). Figure 3 Opposite face.

[0077] The first wall component 131A is a comb-shaped component with a plurality of walls along the main scanning direction. Further explanation reveals that the first wall component 131A has a plurality of optical axis grooves 135 formed along the optical axis direction on its first side surface 133. These plurality of optical axis grooves 135 are arranged at predetermined intervals along the main scanning direction. Each of the plurality of optical axis grooves 135 is formed at a position through which the optical axis of the first lens 173 passes. Incidentally, the intervals of the optical axis grooves 135 in the main scanning direction coincide with the intervals of the first lenses 173 in the first lens array 170 and the intervals of the second lenses 183 in the second lens array 180.

[0078] Here, as Figure 4 As shown in (b), the first wall member 131A, on the first side surface 133, having a plurality of optical axis grooves 135, can be understood as having a base 132 extending along the main scanning direction in the length direction and a plurality of protrusions 137 protruding from the base 132 in the sub-scanning direction. Here, the front ends 138 of the protrusions 137 are arranged at predetermined intervals in the main scanning direction. Furthermore, the bottoms 139 of the optical axis grooves 135 are arranged at predetermined intervals in the main scanning direction. Additionally, the protrusions 137 in the first wall member 131A, which are the portions sandwiched between the optical axis grooves 135 in the main scanning direction, refer to the portion from the imaginary line IL connecting the bottom 139 of the optical axis groove 135 to the optical axis side of the first lens 173. And the base 132 in the first wall member 131A refers to the portion from the imaginary line IL connecting the bottom 139 of the optical axis groove 135 to the side opposite to the optical axis side of the first lens 173. Figure 4In the example shown in (b), the base 132 is a portion that is generally rectangular in shape when viewed from above. Furthermore, in the first wall member 131A of this embodiment, the base 132 is an example of a first base, and each protrusion 137 is an example of a first protrusion. And in the second wall member 131B of this embodiment, the base 132 is an example of a second base, and each protrusion 137 is an example of a second protrusion.

[0079] In addition, such as Figure 5 As shown in (a), the first wall component 131A and the second wall component 131B are such that the surface on which the optical axis groove 135 is formed, namely the first side surface 133 (see reference). Figure 4 The (a) configuration is arranged in a mutually opposing manner. Furthermore, as... Figure 5 As shown in (a), when viewed along the optical axis, the optical axis grooves 135 are each positioned in accordance with the positions of the first lens 173 and the second lens 183. Furthermore, in this embodiment, the space formed in the light-shielding wall 130 formed with the first wall member 131A and the second wall member 131B facing each other, where there is no base 132 and a plurality of protrusions 137, is an example of a transmission section and a window section. More specifically, each of the plurality of columnar regions formed where there is no base 132 and a plurality of protrusions 137 functions as a window section, and these plurality of windows constitute the transmission section. Additionally, the window section can be an open shape as in this embodiment, rather than a closed shape composed of a circular shape or the like. In other words, the concept of a window section in this embodiment includes framed windows (closed shapes) and frameless windows (open shapes). Furthermore, an example of a window section with a closed shape will be described in the modified example 2 described later.

[0080] In the lens array unit 10 of this embodiment, a light-shielding film 110 is disposed on the incident surface side of the light-shielding wall 130, which is composed of the first wall members 131A and the second wall members 131B. Furthermore, the area directly above the optical axis of the first lens 173 in the aforementioned transmissive portion of the light-shielding wall 130 is not covered by the plurality of film through-holes 113 in the light-shielding film 110 and is exposed. In contrast, the area other than directly above the optical axis of the first lens 173 in the transmissive portion of the light-shielding wall 130 is covered by the plurality of film through-holes 113 in the light-shielding film 110. Therefore, the opening formed by the plurality of film through-holes 113 in the light-shielding film 110 is narrower than the window portion constituting the transmissive portion of the light-shielding wall 130. Furthermore, from another perspective, it can be considered that the light-shielding film 110 in this embodiment covers a portion of the area where the first wall members 131A and the second wall members 131B are not present. Therefore, when viewing the entire lens array unit 10 from the incident surface side, the transmissive portion (see reference) formed by connecting the S-shaped opening (window) formed by the first wall member 131A and the second wall member 131B cannot be visually identified. Figure 5 (a)) and the plurality of membrane through-holes 113 provided on the light-shielding membrane 110 can be visually identified only (see reference). Figure 3 ).

[0081] <Operation of Lens Array Unit 10>

[0082] In the lens array unit 10 configured as described above, light reflected from the image reading area La is imaged on the light receiving element 74 via the light-shielding film 110, the light-shielding wall 130, the first lens array 170, and the second lens array 180. At this time, an intermediate imaging surface is formed in the optical path located between the first lens array 170 and the second lens array 180, and an equal-magnification upright real image is formed on the light receiving element 74 located on the exit surface side of the second lens array 180.

[0083] In this embodiment, a light-shielding film 110 with an opening diameter narrower than the diameter of a window portion in the light-shielding wall 130, which is formed by the first wall member 131A and the second wall member 131B, is provided on the incident surface side. Therefore, compared to the case where a light-shielding film 110 with an opening having the same shape as the window portion of the light-shielding wall 130 is provided, it is possible to limit the light from the image reading area La towards the light-shielding wall 130 that is about to enter through the region between the first column R11 and the second column R12 in the light-shielding film 110. As a result, at the focal point where an equal-sized upright real image is formed, the light that should be located on the outermost edge is blocked by the light-shielding film 110. Consequently, the field of view of the first lens 173 and the second lens 183 is reduced, and the depth of focus may increase.

[0084] Furthermore, by employing the above structure, a portion of the light reflected by the optical axis groove 135 or bottom 139 of the light reaching the interior of the light-shielding wall 130 via the light-shielding film 110 can be blocked, thus making it difficult to generate stray light. In addition, stray light refers to light rays emitted from the object point on the object surface that reach a point other than the corresponding image point on the image surface.

[0085] Furthermore, as described above, the light-shielding film 110 is made of a resin material mixed with black pigment. In this way, by making the light-shielding film 110 black, the reflection of light reaching the light-shielding film 110 can be suppressed.

[0086] <Variation Example 1>

[0087] Figure 6 (a) to Figure 6 (d) is a diagram showing a modified example of the light-shielding film 110.

[0088] Next, refer to Figure 6 (a) to Figure 6 (d) A modified example of the light-shielding film 110 will be described. In the above description, the light-shielding film 110 (refer to...) Figure 6 (a) The case of a generally circular membrane through-hole 113 formed on a plate surface 111 that is generally rectangular in shape when viewed from above has been described, but it is not limited to this. As long as the light-shielding film 110 is a structure that is provided in the optical axis direction on the side opposite to the first lens 173 and the second lens 183 across the light-shielding wall 130 and cuts off a portion of the light entering the light-shielding wall 130, its shape is not particularly limited. That is, the shape of the opening provided in the limiting body can also be an open shape composed of a U-shape or the like, rather than as shown in the diagram. Figure 3 The diagram shows a closed shape composed of circular shapes, etc. In other words, the concept of an opening in this embodiment includes a framed window portion (closed shape) and a frameless window portion (open shape).

[0089] For example, it could be like Figure 6 As shown in (b), the light-shielding film 210 has a structure with a generally semi-circular through-hole 213 formed on the generally rectangular plate surface 211 when viewed from above. Here, Figure 6 The light-shielding film 210 shown in (b) can be understood as the light-shielding film 110 (refer to) Figure 6 The shape is formed by cutting off both ends of (a) in the width direction. For example, if the width direction length W1 of the light-shielding film 110 is set to 2 mm, then the width direction length W2 of the light-shielding film 210 becomes 0.75 mm.

[0090] Furthermore, it can also be like this Figure 6 The light-shielding film 310 shown in (c) has a structure with a through hole 313 formed on a plate surface 311 that is generally rectangular in shape when viewed from above. The through hole 313 is generally semicircular, and more specifically, it is a so-called bow shape formed by arcs and chords with a region narrower than a semicircle. Figure 6 The light-shielding film 310 shown in (c) can be understood as the light-shielding film 110 (refer to) Figure 6 The shape cut off at both ends in the width direction of (a)). For example, if the width direction length W1 of the light-shielding film 110 is set to 2 mm, then the width direction length W3 of the light-shielding film 310 becomes 0.6 mm.

[0091] Furthermore, it can also be like this Figure 6 The light-shielding film 410 shown in (d) has a roughly rectangular shape when viewed from above. That is, it may not have membrane through-holes 113 (see reference). Figure 6 The structure of (a)). The light-shielding film 410 can be understood as an elongated member disposed along the first column R71 and the second column R72 between the first lens 173 in the sub-scanning direction. For example, the width direction length W4 of the light-shielding film 410 is 0.18 mm.

[0092] Figure 7 (a) and Figure 7Figure (b) is a diagram showing the simulation results after changing the shape of the light-shielding film 110. More specifically, Figure 7 Figure (a) is a diagram showing the simulation results of the depth of focus in the main scanning direction when the shape of the light-shielding film 110 is changed. Furthermore, Figure 7 (b) is a diagram showing the simulation results of the depth of focus in the sub-scanning direction when the shape of the light-shielding film 110 is changed.

[0093] in addition, Figure 7 (a) and Figure 7 The resolution in (b) is the relative value of the density contrast of the read image on the original G when the density contrast of the written line image data is set to 100%. Furthermore, as a simulation condition, for example... Figure 2 The light-transmitting array unit, which is arranged with a light-shielding wall 130, a first lens array 170 and a second lens array 180 stacked in sequence as shown in the lens array unit 10, is equipped with light-shielding films 110 of various shapes.

[0094] Furthermore, "semicircle 0.6" refers to a light-shielding film where the two sides of the light-shielding film 110 in the sub-scanning direction are cut off, thus setting the width length of the light-shielding film 110 to 0.6 mm. Also, as a comparison, the condition of not providing the light-shielding film 110 is set to "no film". And "line 0.18" is... Figure 6 (d) light-shielding film 410, "semi-circle 0.6" is Figure 6 (c) The light-shielding film 310, "semicircle 0.75" is Figure 6 (b) The light-blocking film 210, "circle" is Figure 6 (a) The light-blocking film 110.

[0095] Next, refer to Figure 6 (a) to Figure 6 (d) Figure 7 (a) and Figure 7 (b) illustrates the simulation results when the shape of the light-shielding film 110 is changed.

[0096] like Figure 7 (a) and Figure 7 As shown in (b), the depth of focus in the main scanning direction and the depth of focus in the sub-scanning direction are simulated in each of the above-mentioned light-shielding films 110, 210, 310, 410 and the "semi-circle 0.65" light-shielding film (not shown).

[0097] according to Figure 7 (a) and Figure 7(b) shows that a greater depth of focus than "without thin film" was obtained in all three cases: "line 0.18", "semicircle 0.6", "semicircle 0.65", "semicircle 0.75", and "circle". That is, it was confirmed that the optical performance (depth of focus in this case) of the lens array unit 10 was improved by configuring the light-shielding film 110. Furthermore, in the light-shielding film 410 of "line 0.18", it was confirmed that... Figure 7 The depth of focus in the sub-scanning direction shown in (b) is greater than that in "no film".

[0098] <Variation Example 2>

[0099] Figure 8 This is a diagram illustrating a modified example of the light-shielding wall 130, and an exploded perspective view of the lens array unit 10 including the modified light-shielding wall 130. Figure 8 In the lens array unit 10 shown, regarding the constituent elements other than the light-shielding wall 130 (light-shielding film 110, first lens array 170, and second lens array 180), and... Figure 3 The constituent elements shown are basically the same, so their detailed descriptions are omitted here.

[0100] <Light-shielding wall 130>

[0101] like Figure 8 As shown, the light-shielding wall 130, as an example of a light-shielding body, is composed of a single wall component 131. To explain further, the light-shielding wall 130 has a wall component 131 provided with a plurality of wall through holes 134.

[0102] As an example of a light-shielding part, the wall component 131 is made of a resin material (e.g., polycarbonate or acrylic resin) mixed with black pigment. Moreover, the wall component 131 is a generally cuboid-shaped component, with its length direction arranged along the main scanning direction.

[0103] The plurality of wall-penetrating holes 134 provided on the light-shielding wall 130 are approximately circular. Furthermore, the position of each wall-penetrating hole 134 corresponds to the first lens 173 and the second lens 183. That is, each wall-penetrating hole 134 is formed at a position through which the optical axis of the first lens 173 passes. Moreover, the wall-penetrating holes 134 are arranged in a first column R31 and a second column R32 along the main scanning direction. To further explain, the wall-penetrating holes 134 correspond to each of the optical axes of the first lens 173. From another viewpoint, each wall-penetrating hole 134 provided on the light-shielding wall 130 corresponds to each film-penetrating hole 113 provided on the light-shielding film 110. In this case, the first column R31 of the light-shielding wall 130 corresponds to the first column R11 of the light-shielding film 110, and the second column R32 of the light-shielding wall 130 corresponds to the second column R12 of the light-shielding film 110.

[0104] Therefore, in the state of forming the lens array unit 10, each membrane through hole 113 (an example of an opening) provided in the light-shielding film 110 and each wall through hole 134 (an example of a window) provided in the light-shielding wall 130 overlap in the optical axis direction.

[0105] <Relationship between light-shielding wall 130 and light-shielding film 110>

[0106] Figure 9 (a) and Figure 9 Figure (b) is used to illustrate the relationship between the wall penetration hole 134 and the membrane penetration hole 113 in a modified example of the light-shielding wall 130. More specifically, Figure 9 Figure (a) is a diagram illustrating the inner diameter, or diameter D3, of the wall penetration hole 134 provided in the light-shielding wall 130. Furthermore, Figure 9 (b) is a diagram used to illustrate the inner diameter of the membrane through-hole 113 provided on the light-shielding film 110, namely the membrane through-hole diameter D1.

[0107] In this example, the wall penetrations 134 provided in the light-shielding wall 130 are circular in shape. Furthermore, the membrane penetrations 113 provided in the light-shielding film 110 are also circular in shape. However, as... Figure 9 (a) and Figure 9 As shown in (b), the inner diameter of each membrane through-hole 113, i.e., the membrane through-hole diameter D1, is smaller than the inner diameter of each wall through-hole 134, i.e., the wall through-hole diameter D3 (D1 < D3). Furthermore, when the light-shielding film 110 overlaps with the light-shielding wall 130, the periphery of each membrane through-hole 113 on the light-shielding film 110 extends closer to the inner side than the periphery of each wall through-hole 134 on the light-shielding wall 130. Therefore, when viewing the entire lens array unit 10 from the incident surface side, the plurality of wall through-holes 134 formed on the wall member 131 cannot be directly visually identified, but can be visually identified through the plurality of membrane through-holes 113 on the light-shielding film 110.

[0108] <Operation of Lens Array Unit 10>

[0109] exist Figure 8 The lens array unit 10 shown also performs the same operation as... Figure 3 The lens array unit 10 shown operates essentially the same. That is, in the lens array unit 10, light reflected from the image reading area La is imaged on the light receiving element 74 via the light-shielding film 110, the light-shielding wall 130, the first lens array 170, and the second lens array 180. At this time, an intermediate imaging surface is formed in the optical path located between the first lens array 170 and the second lens array 180, and an equal-magnification upright real image is formed on the light receiving element 74 located on the exit surface side of the second lens array 180.

[0110] Figure 10 (a) and Figure 10 (b) is a diagram illustrating the relationship between the presence or absence of the light-shielding wall 130 and the light-shielding film 110 in the lens array unit 10 and the depth of focus. More specifically, Figure 10 (a) is a diagram illustrating the depth of focus when the light-shielding wall 130 and the light-shielding film 110 are absent. Figure 10 (b) is a diagram illustrating the depth of focus when the light-shielding wall 130 and the light-shielding film 110 are present. Additionally, Figure 10 (a) and Figure 10 Example (b) illustrates the incident and exit light from two adjacent lenses (lens 173 and lens 183) along the main scanning direction. Furthermore, Figure 10 Example (b) illustrates a case where the opening formed by the light-shielding film 110 covering the light-shielding wall 130 is narrower than the window formed by the light-shielding wall 130.

[0111] First, refer to Figure 10 (a) explains the situation of the previous structure.

[0112] The light reflected from the image reading area La is incident light Li and directed toward the two adjacent first lenses 173. For convenience, the incident light Li will be described as first light L1, second light L2, and third light L3. First light L1 refers to the incident light Li directed toward the boundary portion of the two adjacent first lenses 173. Second light L2 is the incident light Li adjacent to the first light L1 along the main scanning direction, directed toward the central portion of each of the two adjacent first lenses 173. Third light L3 is the incident light Li adjacent to the second light L2 along the main scanning direction, directed toward the ends opposite the boundary portions of the two adjacent first lenses 173.

[0113] Incident light L1, which enters from the incident surface of each of the first lenses 173, exits from their respective exit surfaces. When viewed from the boundary side of each of the first lenses 173, the light exiting from the exit surface of each of the first lenses 173 follows the same order as the light from the incident surface of each of the first lenses 173: first light L1, second light L2, and third light L3. Furthermore, the light passing through each of the first lenses 173 is focused by the action of each of the first lenses 173, forming an intermediate imaging surface in the space between each of the first lenses 173 and each of the second lenses 183, and then diffuses towards the two adjacent second lenses 183. When viewed from the boundary side of each of the second lenses 183, the light incident on the incident surface of each of the second lenses 183 follows the order: third light L3, second light L2, and first light L1. Thus, on the incident surface side of each first lens 173 and on the incident surface side of each second lens 183, the order of the first light L1 to the third light L3 is reversed.

[0114] Light incident from the incident surfaces of each of the second lenses 183 exits from their respective exit surfaces. Here, the light exiting from the exit surfaces of each of the second lenses 183 is referred to as the outgoing light Lo. When viewed from the boundary side of each of the second lenses 183, the outgoing light Lo, like the light from the incident surfaces of each of the second lenses 183, follows the sequence of third light L3, second light L2, and first light L1. Furthermore, the outgoing light Lo passing through each of the second lenses 183 is focused by the action of each second lens 183, forming an upright real image of equal magnification on the exit surface side (light receiving element 74 side) of each of the second lenses 183. Thus, in the conventional structure, the outgoing light Lo, composed of the first light L1, second light L2, and third light L3, forms an upright real image of equal magnification. The angle formed when the outgoing light Lo is focused is called the focusing angle θ.

[0115] Next, refer to Figure 10 (b) explains the structure of variation example 2.

[0116] The light reflected from the image reading area La is incident light Li, comprising the first light L1, the second light L2, and the third light L3, and is directed toward the two adjacent first lenses 173. However, in this case, a light-shielding wall 130 and a light-shielding film 110 are provided on the incident surface side of each first lens 173. Therefore, the innermost first light L1 in the incident light Li is blocked by the light-shielding film 110. As a result, the second light L2 and the third light L3 in the incident light Li reach the two adjacent first lenses 173.

[0117] The second light L2 and the third light L3, incident from the incident surfaces of each of the first lenses 173, exit from their respective exit surfaces. When viewed from the boundary side of each of the first lenses 173, the light exiting from the exit surface of each of the first lenses 173 follows the same order as the light from the incident surface of each of the first lenses 173: second light L2 and third light L3. Furthermore, the light passing through each of the first lenses 173 is focused by the action of each of the first lenses 173, forming an intermediate imaging surface in the space between each of the first lenses 173 and each of the second lenses 183, and then diffuses towards the two adjacent second lenses 183. When viewed from the boundary side of each of the second lenses 183, the light incident on the incident surfaces of each of the second lenses 183 follows the same order: third light L3 and second light L2. Thus, the order of the second light L2 and the third light L3 is reversed on the incident surface side of each of the first lenses 173 and the incident surface side of each of the second lenses 183.

[0118] Light incident from the incident surfaces of each of the second lenses 183 exits as outgoing light Lo from their respective exit surfaces. When viewed from the boundary side of each of the second lenses 183, the outgoing light Lo, like the third light L3 and the second light L2, is in the same order as the incident light side of each of the second lenses 183. Furthermore, the outgoing light Lo passing through each of the second lenses 183 is focused by the action of each second lens 183 and forms an upright real image of equal magnification on the exit surface side (light receiving element 74 side) of each of the second lenses 183. Thus, in the case of the structure of Modified Example 2, the outgoing light Lo, composed of the second light L2 (excluding the first light L1) and the third light L3, forms an upright real image of equal magnification. Furthermore, in this case, by setting the light-shielding film 110 and the light-shielding wall 130, the first light L1, which should be located on the outermost side of the emitted light Lo, is excluded from the emitted light Lo, and therefore the focusing angle θ becomes smaller than 100°. Figure 10 As shown in (a), the previous situation can make the depth of focus deeper (greater).

[0119] <Variation Example 3>

[0120] In the above-described modified example, the wall penetration hole 134 provided in the light-shielding wall 130 is circular, and the membrane penetration hole 113 provided in the light-shielding film 110 is also circular, but it is not limited to this.

[0121] Figure 11 (a) and Figure 11 Figure (b) is used to illustrate the relationship between the wall penetration hole 134 and the membrane penetration hole 113 in a modified example of the light-shielding film 110. More specifically, Figure 11 Figure (a) is used to illustrate the wall through-hole 134 provided in the light-shielding wall 130. Furthermore, Figure 11 Figure (b) illustrates the membrane through-hole 113 provided in the light-shielding film 110. Furthermore, regarding the constituent elements of the lens array unit 10 other than the light-shielding film 110 (light-shielding wall 130, first lens array 170, and second lens array 180), and... Figure 8 The constituent elements shown are basically the same, so their detailed descriptions are omitted here.

[0122] In this example, the wall penetration 134 of the light-shielding wall 130 is circular, while the membrane penetration 113 of the light-shielding film 110 is non-circular. To explain in more detail, the membrane penetration 113 of the light-shielding film 110 is approximately circular at both ends in the sub-scanning direction, and approximately straight at both ends in the main scanning direction. This restricts the light in the incident light Li directed towards the ends of each first lens 173 in the main scanning direction.

[0123] When using Figure 9In the structure shown, the area of ​​the film penetration 113 in the light-shielding film 110 becomes smaller, therefore the amount of light in the obtained upright real image of equal size may be insufficient. In contrast, by employing... Figure 11 The structure shown ensures that the area of ​​the membrane through-hole 113 provided in the light-shielding film 110 is greater than that of the structure described above. Figure 9 The structure shown correspondingly enables the suppression of insufficient light in the obtained upright real image of equal size. Furthermore, by employing... Figure 11 The structure shown makes it less likely that light incident on a certain membrane through-hole 113 will be incident on a first lens 173 that is provided for other membrane through-holes 113 adjacent to the membrane through-hole 113 along the main scanning direction.

[0124] <Other>

[0125] Furthermore, while the above embodiments use a light-shielding film 110 made of a resin material mixed with black pigment, the method is not limited to this. For example, a light-shielding film 110 formed by coating a film containing a transparent resin material with black pigment through printing or the like can also be used. In this case, a light-transmitting portion can be provided by making openings in specific areas of the light-shielding film 110, or a light-transmitting portion can be provided without printing on specific areas of the light-shielding film 110.

[0126] Furthermore, in the above embodiments, a transmissive portion is formed by providing a space (through hole) in the light-shielding wall 130, but it is not limited to this. Regarding the light-shielding wall 130, for example, it may be formed by combining a light-shielding portion made of a non-transparent resin or the like with a transmissive portion made of a translucent resin or the like, or it may be formed by printing the transmissive portion and the light-shielding portion onto the surface of the transparent component.

[0127] Furthermore, in the above embodiments, two lens arrays (first lens array 170 and second lens array 180) are used to construct the lens body, but it is not limited to this. That is, as long as the intermediate imaging surface for forming an upright real image of equal magnification is formed in the optical path, the number of lens arrays can be one or more.

[0128] Furthermore, in the above embodiments, the plurality of first lenses 173 constituting the first lens array 170 and the plurality of second lenses 183 constituting the second lens array 180 are arranged in two columns, but this is not a limitation. For example, they may be arranged in three or more columns.

[0129] Furthermore, in the above embodiments, the light-shielding film 110 and the light-shielding wall 130 are individually constructed, but they can also be molded as a whole, or they can be molded in a form that narrows towards the original document side (incident surface side).

[0130] The embodiments of the present invention described above are provided for illustrative and explanatory purposes. Furthermore, these embodiments do not encompass the entirety of the invention, nor do they limit the invention to the disclosed methods. It will be apparent to those skilled in the art that various modifications and variations will be readily understood. These embodiments were chosen and described to most readily explain the principles and applications of the invention. Thus, those skilled in the art can understand the invention through various modifications that optimize the determination of the various assumed embodiments. The scope of the invention is defined by the foregoing claims and their equivalents.

Claims

1. An optical device comprising: A lens body having a plurality of lenses arranged in parallel with their respective optical axes, and an intermediate imaging surface for forming an upright real image of equal magnification is formed in the optical path; A light-shielding body is provided facing the incident surface of light in the lens body, and has a transmissive part located on the optical axis of the plurality of lenses and allowing light to pass through, and a light-shielding part located at a position other than the optical axis of the plurality of lenses and blocking the passage of light. and A limiting body is disposed opposite to the incident surface of light in the light-shielding body, and has an opening narrower than the transmissive portion and restricts a portion of the light toward the transmissive portion.

2. The optical device according to claim 1, characterized in that, The light-shielding body has: The base is disposed on the side of the plurality of lenses along the direction in which the plurality of lenses are arranged, i.e., the arrangement direction; and A plurality of protrusions, which protrude from the base in a cross direction intersecting the arrangement direction between the lenses of the plurality of lenses, wherein the light-shielding portion includes the base and the plurality of protrusions. The limiting body covers a portion of the area in the light-shielding body where the base and the plurality of protrusions are not present.

3. The optical device according to claim 2, characterized in that, The plurality of lenses are arranged in the first and second columns along the arrangement direction. The light-shielding body has: The first light shield has: a first base disposed on the side of the lenses in the first column along the arrangement direction; and a plurality of first protrusions protruding from the first base toward the crossing direction between the lenses in the first column. and The second light-shielding body has: a second base disposed on the side of the lenses in the second column and separated from the lenses in the first column and the second column, on the side opposite to the first base along the arrangement direction; and a plurality of second protrusions protruding from the second base toward the crossing direction between the lenses in the second column. The limiting body covers a portion of the area in the light-shielding body where neither the first light-shielding body nor the second light-shielding body exists.

4. The optical device according to claim 3, characterized in that, The limiting body covers the space between the plurality of first protrusions in the first light-shielding body and the plurality of second protrusions in the second light-shielding body along the arrangement direction.

5. The optical device according to claim 1, characterized in that, The light-shielding body includes: a light-shielding portion that covers a portion of each of the plurality of lenses other than the incident surface; and a transmission portion formed by a plurality of windows disposed on the light-shielding portion. The limiting body covers the inner periphery of the light-shielding portion in the light-shielding body and the periphery of each of the plurality of windows forming the light-shielding portion.

6. The optical device according to claim 5, characterized in that, The limiting body is provided with an opening corresponding to each of the plurality of lenses. The diameter of the opening in the limiting body is smaller than the diameter of the window in the light-shielding body.

7. The optical device according to claim 1, characterized in that, The lens body has: A first lens body comprises a plurality of first lenses arranged in parallel with their respective optical axes, and is disposed facing the light-emitting surface in the light-shielding body, and the light transmitted through the plurality of first lenses forms the intermediate imaging surface; and The second lens body comprises a plurality of second lenses arranged in parallel with their respective optical axes, and is positioned opposite to the light exiting surface of the first lens body. Light that has passed through the first lens body and formed the intermediate imaging surface is incident thereon. The limiting body restricts light incident on the peripheral side of each of the plurality of first lenses disposed on the first lens body.

8. An image reading device, comprising: The irradiation section, which illuminates the original manuscript with light; A lens body comprising a plurality of lenses arranged in a manner that allow light reflected from the original to pass through, each having its own optical axis parallel to the others. A light-shielding body is provided facing the incident surface of light in the lens body, and has a transmissive part located on the optical axis of the plurality of lenses and allowing light to pass through, and a light-shielding part located at a position other than the optical axis of the plurality of lenses and blocking the passage of light. A limiting body, which is disposed opposite to the incident surface of light in the light-shielding body, and has an opening narrower than the transmissive portion and restricts a portion of the light toward the transmissive portion; and A light receiving unit that receives light passing through the plurality of lenses.

9. An image forming apparatus comprising: The irradiation section, which illuminates the original manuscript with light; A lens body comprising a plurality of lenses arranged in a manner that allow light reflected from the original to pass through, each having its own optical axis parallel to the others. A light-shielding body is provided facing the incident surface of light in the lens body, and has a transmissive part located on the optical axis of the plurality of lenses and allowing light to pass through, and a light-shielding part located at a position other than the optical axis of the plurality of lenses and blocking the passage of light. A limiting body is disposed opposite to the incident surface of light in the light-shielding body, and has an opening narrower than the transmissive portion and restricts a portion of the light toward the transmissive portion; A light receiving unit that receives light passing through the plurality of lenses; and An image forming unit forms an image based on the light received by the light receiving unit.

Images