Optical member and image reading apparatus

Abstract

An optical member (1) includes a lens array (6) having a plurality of lens bodies (5), and a plurality of transmission members (7). The plurality of transmission members (7) are formed of members having the same refractive index and are respectively provided at positions closer to a reading target object (D) than the corresponding lens bodies (5) or at positions farther from the reading target object (D) than the lens bodies (5). Each transmission member (7) has a columnar shape extending along an optical axis of the lens body (5) and causes light incident from one end surface to be emitted from the other end surface. At least one of the plurality of lens bodies (5) and the plurality of transmission members (7) are arranged so as to have a larger interval between each other than an arrangement error of the plurality of lens bodies (5) and the plurality of transmission members (7).

Description

Technical Field

[0001] This disclosure relates to optical components and image reading devices. Background Technology

[0002] Image reading devices include those that illuminate an object to be read, focus transmitted or reflected light from the object through a plurality of lenses arranged in an array, and then read the light by a plurality of photosensitive elements arranged in a line. An example of such an image reading device is disclosed in Patent Documents 1 and 2.

[0003] Lens arrays used as image reading devices employ upright equal-magnification optical systems, specifically rod-shaped lens arrays or microlens arrays with multiple cylindrical lens bodies.

[0004] In order to increase the depth of field when using the above-described lens array, the image reading apparatus disclosed in Patent Documents 1 and 2 includes an overlap limiting member disposed between the lens elements. By using the overlap limiting member to limit the overlap of images caused by multiple lens elements, the imaging diameter of each lens element can be controlled, thereby increasing the depth of field.

[0005] As an example of an overlap-limiting component, the image reading device disclosed in Patent Document 2 includes a light-transmitting cylindrical array having multiple light-transmitting cylindrical portions. The light-transmitting cylindrical portions are arranged between the lens array and the sensor element array according to each optical axis of the lens body, so that light incident from one end face of the lens body exits towards the sensor element from the other end face. By adjusting the length of the light-transmitting cylindrical portions along the optical axis, overlap of images formed by the lens body can be prevented.

[0006] Patent Document 1: Japanese Patent Application Publication No. 6-342131

[0007] Patent Document 2: International Publication No. 2020 / 196168

[0008] The image reading device disclosed in Patent Document 2 includes: lens bodies that abut against each other, and light-transmitting cylindrical portions that are respectively arranged and abut against each other for each lens body. If the optical axis of the lens body is misaligned with the central axis of the light-transmitting cylindrical portion, light emitted from the lens body will be incident on the light-transmitting cylindrical portion adjacent to the light-transmitting cylindrical portion corresponding to that lens body. As a result, sometimes overlapping images formed by adjacent lens bodies will occur. Summary of the Invention

[0009] This disclosure was made to solve the aforementioned problems, and aims to provide an optical component and an image reading device that suppresses the overlap of images formed by a lens even when errors occur in the arrangement position of at least one of the lens body and the transmission component that limits the overlap of images formed by the lens body.

[0010] The optical component disclosed herein includes a lens array and multiple transmitting elements. The lens array has multiple lens bodies arranged in a row along the main scanning direction to converge light from the object being read. The multiple transmitting elements are formed of components with the same refractive index and are respectively disposed at positions closer to or farther from the object being read than the corresponding lens body, and have a columnar shape extending along the optical axis of the lens body, so that light incident from one end face is emitted from the other end face. At least one of the multiple lens bodies and the multiple transmitting elements is arranged with a spacing between each other that is larger than the arrangement error of the multiple lens bodies and the multiple transmitting elements.

[0011] The optical component disclosed herein includes: a plurality of lens bodies; and a plurality of transmitting elements corresponding to each lens body, such that light incident from one end face exits from the other end face. By providing the transmitting elements, image overlap formed by adjacent lens bodies in the main scanning direction is suppressed. At least one of the plurality of lens bodies and the plurality of transmitting elements is arranged such that it is spaced apart from each other by an interval larger than the arrangement error of the plurality of lens bodies and the plurality of transmitting elements, thus enabling an optical component that can suppress image overlap formed by the lens bodies even if the arrangement position of at least one of the lens bodies and the transmitting elements is incorrect. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view of the image reading device according to Embodiment 1.

[0013] Figure 2 This is a perspective view of the optical component according to Embodiment 1.

[0014] Figure 3 This is an exploded perspective view of the optical components of Embodiment 1.

[0015] Figure 4 This is a perspective view of the through-hole component in Embodiment 1.

[0016] Figure 5 This is a diagram showing the positional relationship between the optical components and the sensor array in Embodiment 1.

[0017] Figure 6 This is a diagram showing the positional relationship between the lens and the transmission component of the optical component in Embodiment 1.

[0018] Figure 7 This is a diagram showing the positional relationship between the optical components and the sensor array in Embodiment 2.

[0019] Figure 8 This is a diagram showing the positional relationship between the lens and the transmission component of the optical component in Embodiment 2.

[0020] Figure 9 This is a cross-sectional view of the image reading device according to Embodiment 3.

[0021] Figure 10 This is a perspective view of the optical component of embodiment 3.

[0022] Figure 11 This is an exploded perspective view of the optical components of Embodiment 3.

[0023] Figure 12 This is a diagram showing the positional relationship between the optical components and the sensor array in Embodiment 3.

[0024] Figure 13 This is a cross-sectional view of a first modified example of the image reading device according to the embodiment.

[0025] Figure 14 This is a cross-sectional view of a second variation of the image reading device according to the embodiment.

[0026] Figure 15 This is a cross-sectional view of a third variation of the image reading device according to the embodiment.

[0027] Figure 16 This is a cross-sectional view of a fourth variation of the image reading device according to the embodiment.

[0028] Figure 17 This is a diagram showing the positional relationship between the optical components and the sensor array included in the fourth modification of the image reading device according to the embodiment.

[0029] Figure 18 This is another example of the positional relationship between the optical components and the sensor array in an embodiment.

[0030] Figure 19 This is another example of the positional relationship between the lens and the transmission component of the optical component in the embodiment.

[0031] Figure 20 This is another example of the positional relationship between the lens and the transmission component of the optical component in the embodiment. Detailed Implementation

[0032] Hereinafter, the optical components and image reading device of the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, the same reference numerals are used to denote the same or equivalent parts in the drawings.

[0033] (Implementation Method 1)

[0034] For example, taking an image reading device that reads images, text, patterns, and other information on the surface of the object being read, such as a sheet-like component, substrate, or mesh of sheet-like fibers (including documents, banknotes, securities, etc.), as an example, the image reading device 2 of Embodiment 1 will be described using the accompanying drawings. Figure 1 In the image reading device 2 shown, the main scanning direction is set as the X-axis, the sub-scanning direction is set as the Y-axis, and the reading depth direction is set as the Z-axis. The main scanning direction and the sub-scanning direction intersect, preferably orthogonally. In Embodiment 1, the X-axis, Y-axis, and Z-axis are orthogonal to each other. The same applies in the following figures.

[0035] As shown in the diagram of a cross-section along the sub-scanning direction of the image reading device 2, that is... Figure 1 As shown, the image reading device 2 includes: a light source 9 that emits light toward the object D to be read; a transmission plate 10 that allows light emitted from the light source 9 to pass through; and an optical component 1 having a plurality of lenses that converge the light reflected from the object D. The image reading device 2 also includes: a sensor array 4 having a plurality of sensor elements 3 that receive the light converged by the optical component 1; and a sensor substrate 11 for mounting the sensor array 4. The image reading device 2 also includes a frame 12 for mounting the transmission plate 10 and the sensor substrate 11, and internally housing the light source 9, the optical component 1, and the sensor array 4.

[0036] like Figure 1 As indicated by the dashed arrow, light source 9 is a linear light source that illuminates a line of light at the location through which the object being read, D, passes, i.e., the reading position. It may be formed, for example, by a side-light source. A side-light source is a light source having a light guide extending along the X-axis and a light source element disposed at the X-axis end of the light guide. The light emitted from light source 9 and used to read information from the object being read, D, is, for example, visible light.

[0037] A plate 10 is installed on the frame 12 to block the opening 12a of the frame 12 facing the object being read, thus blocking the opening. The plate 10 allows light emitted from the light source 9 to pass through. More specifically, as... Figure 1 As indicated by the dashed arrow, the transmissive plate 10 is formed of a component with high transmittance, such as transparent glass or transparent resin, to the extent that the light emitted by the light source 9 can illuminate the object to be read, and the light from the object to be read, can be received by the sensor element 3. The transmissive plate 10 has a flat, plate-like shape with two flat surfaces extending along the main scanning direction and the sub-scanning direction. In the transmissive plate 10, the surface opposite to the surface of the opening 12a of the blocking frame 12 forms the reading surface of the object to be read, D. The reading surface limits the reading position of the object to be read, D.

[0038] The frame 12 has a box-shaped form with an opening 12a facing the object being read, D, and an opening 12b facing the opposite side of the opening 12a. The frame 12 is made of a component that blocks light from the outside, such as a metal including aluminum or iron, or resin. The light source 9, optical component 1, and sensor array 4, which are housed in the frame 12, are directly or indirectly mounted on and held in the frame 12. The frame 12 suppresses light from entering the light-receiving part, specifically the sensor element 3, from the outside of the image reading device 2. Furthermore, the frame 12 prevents foreign objects such as dust and moisture from entering the interior of the image reading device 2.

[0039] The sensor substrate 11 is a substrate formed of resin, such as glass epoxy resin. Multiple sensor elements 3 and other components (not shown), such as drive circuitry and signal processing circuitry, are disposed on the sensor substrate 11. The sensor substrate 11 is mounted on the frame 12 with the opening 12b of the sensor element 3 located at the lower vertical position of the frame 12 blocked.

[0040] Multiple sensor elements 3 are arranged along the main scanning direction and fixed to the sensor substrate 11 by fixing components, such as adhesives. Each sensor element 3 is positioned according to a lens body 5 and receives light focused by the corresponding lens body 5. For example, each sensor element 3 is formed by a sensor IC (Integrated Circuit). The sensor element 3 receives the light focused by the corresponding lens body 5, performs photoelectric conversion to convert it into an electrical signal, and outputs it. The electrical signal output by the sensor element 3 is converted into image information by a signal processing circuit.

[0041] like Figure 2 as well as Figure 3 As shown, the optical component 1 includes: a lens array 6 having a plurality of lens bodies 5 arranged in a row along the main scanning direction; and a transmission component array 8 having a plurality of transmission components 7 that allow light incident from one end face to exit from the other end face.

[0042] The lens array 6 has multiple lens bodies 5 and two side plates 56 that hold the multiple lens bodies 5. In embodiment 1, the multiple lens bodies 5 are arranged at intervals between each other in the main scanning direction. The interval between the multiple lens bodies 5 is greater than the arrangement error of the multiple lens bodies 5 and the multiple transmission components 7. Each lens body 5 converges the light from the object being read, D. The extension direction of the optical axis AX1 of the lens body 5 is orthogonal to both the main scanning direction and the sub-scanning direction. In other words, the optical axis AX1 of the lens body 5 extends parallel to the Z-axis. The lens body 5 converges the light emitted from the light source 9 and reflected by the object being read, D. The lens body 5 is preferably formed of a refractive index distribution type lens, i.e., a rod lens, having a cylindrical shape, a different refractive index in the radial direction, and forming an upright, equal-magnification image.

[0043] Two side plates 56 are positioned opposite each other in the Y-axis direction, spaced apart by multiple lens bodies 5. The side plates 56 are formed of a flat, light-shielding component, such as a metal including aluminum or iron, or resin. Preferably, a light-shielding adhesive is filled between the two side plates 56. This suppresses relative positional misalignment between the lens bodies 5 and the side plates 56.

[0044] The transmission element array 8 prevents the images formed by adjacent lens bodies 5 from overlapping; in other words, it separates the optical paths of light converged by adjacent lens bodies 5. The transmission element array 8 has a plurality of transmission elements 7 and two side plates 78 that hold the plurality of transmission elements 7. In embodiment 1, the plurality of transmission elements 7 are arranged at intervals between each other in the main scanning direction. The interval between the plurality of transmission elements 7 is greater than the arrangement error of the plurality of lens bodies 5 and the plurality of transmission elements 7.

[0045] Each transmitting component 7 is provided for each lens body 5, and is positioned either closer to the object to be read D than the corresponding lens body 5 or farther away from the object to be read D than the corresponding lens body 5. In Embodiment 1, the transmitting component 7 is located farther away from the object to be read D than the lens body 5, in other words, it is located between the lens body 5 and the sensor element 3. Each transmitting component 7 is provided in a state where it abuts against the end of the lens body 5 in the direction of the optical axis AX1, specifically the end on the negative Z-axis side.

[0046] The transmitting element 7 is formed of a component with a uniform refractive index at all locations and has a cylindrical shape extending along the optical axis AX1 of the lens body 5. A component with a uniform refractive index means that the refractive index at any location of the component is within a defined range that allows for manufacturing errors. For example, the transmitting element 7 is a cylindrical component formed of glass or resin with a uniform refractive index and transmittance at all locations. The transmitting element 7 is preferably formed of a component with sufficiently small strain, such as a component with no strain. In Embodiment 1, the transmitting element 7 has a cylindrical shape with the same diameter as the lens body 5.

[0047] The light emitted from the light source 9 is transmitted through the transmission component 7. Specifically, the transmission component 7 causes light to enter from one end face and exit from the other end face. In Embodiment 1, the transmission component 7 causes light that enters from the lens body 5 toward the end face of the lens body 5, i.e., the end face toward the positive Z-axis, to exit from the end face toward the sensor element 3, i.e., the end face toward the negative Z-axis.

[0048] Two side plates 78 are positioned opposite each other in the Y-axis direction, separated by a plurality of transparent elements 7. The side plates 78 are formed of flat, light-shielding components, such as metals including aluminum and iron, or resin. Preferably, a light-shielding adhesive is filled between the two side plates 78. This suppresses the relative positional misalignment between the transparent elements 7 and the side plates 78.

[0049] At least one of the following is applied to the side surface of the component 7, in other words, to the outer peripheral surface of the component 7 around the Z-axis: a treatment to suppress diffuse reflection of light incident from the outside to the side surface and a treatment to suppress specular reflection of light incident from the outside to the side surface. In Embodiment 1, as... Figure 4 As shown, the transmitting member 7 has a cylindrical member 71 and a reflection-suppressing member 72 formed by a cylindrical member whose inner circumferential surface abuts against the outer circumferential surface of the cylindrical member 71. Specifically, the reflection-suppressing member 72, formed of black resin, is coated on the outer circumferential surface of the cylindrical member 71, thereby forming the transmitting member 7. The reflection-suppressing member 72, formed of black resin, suppresses light reflection from the side surfaces of the transmitting member 7. Furthermore, the reflection-suppressing member 72 absorbs light that travels from the interior of the transmitting member 7 through the side surfaces to the exterior. Alternatively, a light-shielding adhesive filled between the two side plates 78 can be used as the reflection-suppressing member 72.

[0050] like Figure 5 And a diagram showing the lens array 6 viewed along the positive Z-axis. Figure 6 As shown, sometimes the central axis C1 of each transmitting component 7 is misaligned with the optical axis AX1 of the lens body 5, and the end face of the transmitting component 7 is misaligned with the corresponding end face of the lens body 5. Figure 5 and Figure 6 The diagram illustrates an example where the arrangement of at least one of the lens bodies 5 and the transmitting components 7 results in an error; specifically, an example where the lens bodies 5 are arranged at equal intervals, and the transmitting components 7 are arranged at unequal intervals. Figure 6 In the diagram, solid lines represent the outline of the lens body 5, and dashed lines represent the outline of the transmission component 7. Figure 5 In the example, the central axis C1 of the left-hand transmitting component 7 coincides with the optical axis AX1 of the left-hand lens body 5, but the central axis C1 of the other transmitting components 7 does not coincide with the optical axis AX1 of the corresponding lens body 5. Therefore, as... Figure 6 As shown, the end face of the left-hand transmission component 7 is aligned with the end face of the corresponding lens body 5, but the end faces of the other transmission components 7 are offset from the end faces of the corresponding lens body 5.

[0051] If the central axis C1 of component 7 is misaligned with the optical axis AX1 of lens body 5, then a portion of the light emitted from lens body 5 will be like... Figure 5 As indicated by the dashed arrow, light does not enter the transmitting member 7 corresponding to the lens body 5, i.e., the transmitting member 7 that abuts against the lens body 5, but instead propagates towards the adjacent transmitting member 7. A reflection suppression member 72 is provided on the side of the transmitting member 7 as described above, thus absorbing the light reaching the side of the adjacent transmitting member 7. The transmitting members 7 are arranged at intervals, and the reflection suppression member 72 is provided on the side of the transmitting member 7, thereby separating the light path converged by the adjacent lens bodies 5 even if the central axis C1 of the transmitting member 7 is misaligned with the optical axis AX1 of the lens body 5.

[0052] like Figure 5 As indicated by the arrows in the solid line, a portion of the light incident from the lens 5 onto one end face of the transmitting member 7 travels straight through the transmitting member 7 and reaches the sensor element 3. Another portion of the light incident from the lens 5 onto one end face of the transmitting member 7 reaches the side face of the transmitting member 7. If the angle of incidence when reaching the side face of the transmitting member 7 is greater than or equal to the critical angle, total internal reflection occurs, and the light travels straight through the transmitting member 7 and reaches the sensor element 3. If light incident at a large angle relative to the central axis C1 onto one end face of the transmitting member 7 reaches the side face of the transmitting member 7, the angle of incidence at the side face of the transmitting member 7 is small, therefore total internal reflection does not occur. Instead, the light is refracted and incident on the reflection suppression member 72 located on the side face of the transmitting member 7 and absorbed.

[0053] By increasing the length of the transmitting element 7 in the direction of the optical axis AX1 of the lens body 5, or in other words, in the Z-axis direction, light incident from one end face of the transmitting element 7 is prevented from reaching the side face of the transmitting element 7 and exiting directly from the other end face. As a result, light incident at an angle significantly inclined relative to the central axis C1 onto one end face of the transmitting element 7 does not reach the other end face of the transmitting element 7 and does not exit from the other end face of the transmitting element 7. In other words, the light emitted from the transmitting element 7 is light whose angle of incidence at the side face of the transmitting element 7 is above the critical angle.

[0054] Multiple lens bodies 5 are arranged at intervals, and multiple transmitting components 7 are arranged at intervals, also at intervals. Therefore, as... Figure 5 As shown, multiple sensor elements 3 are provided for each lens body 5 and arranged at intervals. The sensor elements 3 are arranged at intervals such that when light with an incident angle greater than or equal to the critical angle on the side of the transmitting member 7 is emitted from the other end face of the transmitting member 7, the light emitted from the transmitting member 7 does not reach other sensor elements 3 adjacent to the sensor element 3 opposite to that transmitting member 7. Furthermore, the sensor elements 3 are arranged at intervals such that light that does not reach the side of the transmitting member 7 but travels straight in and is emitted from the transmitting member 7 does not reach other sensor elements 3 adjacent to the sensor element 3 opposite to that transmitting member 7. As a result, as shown by the dashed arrows, light emitted from different transmitting members 7 is prevented from reaching the same sensor element 3.

[0055] The amount of light received by sensor element 3 when the central axis C1 of component 7 is misaligned with the optical axis AX1 of lens body 5 is less than the amount of light received by sensor element 3 when the central axis C1 of component 7 is aligned with the optical axis AX1 of lens body 5. For high-precision reading of the object D, the offset between the central axis C1 of component 7 and the optical axis AX1 of lens body 5 is preferably within the range where the amount of light received by sensor element 3 is the amount of light required to read the information of object D. Furthermore, the central axis C1 of at least one of the components 7 is preferably aligned with the optical axis AX1 of the corresponding lens body 5.

[0056] As explained above, the optical component 1 of the image reading device 2 in Embodiment 1 includes: a plurality of lens bodies 5 arranged at intervals between each other; and a plurality of transmitting components 7, each corresponding to a lens body 5 and arranged at intervals between each other. Because the plurality of lens bodies 5 and the plurality of transmitting components 7 are arranged at intervals between each other, the plurality of sensor elements 3, each corresponding to a lens body 5, are also arranged at intervals between each other. Therefore, even if the optical axis AX1 of the lens body 5 is not aligned with the central axis C1 of the transmitting component 7, light emitted from the lens body 5 is prevented from being received by the sensor elements 3 corresponding to other lens bodies 5 adjacent to the lens body 5. As a result, even if at least one of the arrangement positions of the lens bodies 5 and the transmitting components 7 is incorrect, the optical component 1 and the image reading device 2 can suppress the overlap of images formed by the lens bodies 5.

[0057] In the spacing between the plurality of lens bodies 5, at least the spacing in the main scanning direction is greater than the arrangement error of the plurality of lens bodies 5. In the spacing between the plurality of transmitting elements 7, at least the spacing in the main scanning direction is greater than the arrangement error of the plurality of transmitting elements 7. Greater than the arrangement error means greater than the maximum value of the assumed arrangement error. At least one of the plurality of lens bodies 5 and the plurality of transmitting elements 7 can be arranged by setting a spacing between them that is greater than the arrangement error of the plurality of lens bodies 5 and the plurality of transmitting elements 7.

[0058] Furthermore, by providing a reflection suppression component 72 on the side of the transmission component 7, the light path of the light converged by the adjacent lens bodies 5 is separated.

[0059] (Implementation Method 2)

[0060] The shape and arrangement of the lens body 5 and the transmission component 7 are not limited to the examples described above. Embodiment 2 will be described focusing on the differences from Embodiment 1, specifically regarding the optical component 1 having a different shape than Embodiment 1 and having the lens body 5 and the transmission component 7 arranged in a different manner, and the image reading device 2 having the optical component 1.

[0061] In Embodiment 2, the image reading device 2 includes an optical component 1 with a plurality of lens bodies 5 and a plurality of transmitting elements 7 arranged at intervals, while the other side of the plurality of lens bodies 5 and the plurality of transmitting elements 7 are arranged in a state of mutual contact. The interval is greater than the arrangement error of the plurality of lens bodies 5 and the plurality of transmitting elements 7. In Embodiment 2, as... Figure 7 And a diagram showing the lens array 6 viewed along the positive Z-axis. Figure 8 As shown, multiple lens bodies 5 are arranged in a contacting state, and multiple transmitting elements 7 are arranged at intervals. The intervals between the multiple transmitting elements 7 in the main scanning direction are greater than the arrangement error of the multiple lens bodies 5 and the multiple transmitting elements 7.

[0062] like Figure 8 As shown, the lens body 5 and the transmitting component 7 are both cylindrical, and the diameter of the lens body 5 is different from the diameter of the transmitting component 7. The diameter of the lens body 5 is larger than the diameter of the transmitting component 7. The lens bodies 5 are arranged in a mutually abutting state, i.e., at equal intervals, while the transmitting components 7 are arranged at unequal intervals. Therefore, in Figure 7 In the middle, the central axis C1 of the left-hand transmission component 7 is aligned with the optical axis AX1 of the corresponding lens body 5, but the central axis C1 of the other transmission components 7 is offset from the optical axis AX1 of the corresponding lens body 5.

[0063] Because the diameter of the transmitting component 7 is smaller than the diameter of the lens body 5, a portion of the light emitted from the lens body 5 is as follows: Figure 7 As indicated by the dashed arrow, light that does not strike the transmitting element 7 corresponding to the lens body 5, i.e., the transmitting element 7 that abuts against the lens body 5, travels towards the adjacent transmitting element 7. Since the lens bodies 5 are arranged in a mutually abutting state, the transmitting elements 7 are arranged at intervals. Therefore, light emitted from the lens body 5 that does not strike the transmitting element 7 that abuts against the lens body 5 does not strike the transmitting element 7 adjacent to it, but travels towards the side of the transmitting element 7. A reflection suppression member 72 is provided on the side of the transmitting element 7, similar to that in Embodiment 1, so light reaching the side of the adjacent transmitting element 7 is absorbed.

[0064] Preferably, the transmitting element 7 is positioned so that the entire end face of the smaller diameter transmitting element 7 faces the end face of the larger diameter lens body 5. In addition, at least one central axis C1 of the transmitting element 7 is preferably aligned with the optical axis AX1 of the corresponding lens body 5.

[0065] As explained above, the optical component 1 of the image reading device 2 in Embodiment 2 includes: a plurality of lens bodies 5 disposed in a state of mutual contact; and a plurality of transmitting components 7, each corresponding to a lens body 5 and disposed at intervals from each other. Since the transmitting components 7 are disposed at intervals from each other, light emitted from a lens body 5 that does not incident on a transmitting component 7 that is in contact with that lens body 5 reaches the side of a transmitting component 7 adjacent to that lens body 5 and is absorbed. Therefore, even if the optical axis AX1 of the lens body 5 is not aligned with the central axis C1 of the transmitting component 7, the light emitted from the lens body 5 is prevented from being received by the sensor element 3 corresponding to the other lens bodies 5 adjacent to the lens body 5. As a result, even if there is an error in the arrangement position of at least one of the lens bodies 5 and the transmitting components 7, an optical component 1 and an image reading device 2 that suppress the overlap of images formed by the lens bodies 5 can be obtained.

[0066] (Implementation Method 3)

[0067] To suppress image overlap formed by the lens body 5, the optical component 1 may also include a light-shielding component. The optical component 1, which also includes a light-shielding component disposed between the lens body 5 of the lens array 6 and the transmission component 7 of the transmission component array 8, and the image reading device 2 equipped with the optical component 1, will be described in Embodiment 3, focusing on the differences from Embodiment 1.

[0068] like Figure 10 and Figure 11 As shown, Figure 9 The image reading device 2 shown includes an optical component 1 comprising: a lens array 6 having a plurality of lens bodies 5 arranged in an adjacent state; and a transmission component array 8 having a plurality of transmission components 7 arranged in an adjacent state. The diameters of the lens bodies 5 and the transmission components 7 are the same, and each has a cylindrical shape.

[0069] like Figure 9 and Figure 10 As shown, the lens array 6 and the transmission component array 8 are arranged at intervals in the Z-axis direction. More specifically, the lens body 5 and the transmission component 7 are arranged at intervals at the ends of the lens body 5 in the extension direction of the optical axis AX1, that is, in the Z-axis direction.

[0070] The optical component 1 also includes at least one light-shielding component 13, which is disposed between the lens body 5 and the transmitting component 7 and at a predetermined distance from the straight line extending the optical axis of the lens body 5. Figure 11 As shown, a plurality of light-shielding members 13 are disposed between the lens array 6 and the transmission member array 8. The light-shielding members 13 are formed of a light-shielding material, such as black resin. Figure 12As shown, each light-shielding component 13 is positioned to abut against two adjacent transmitting components 7. Each light-shielding component 13 is also positioned to abut against the lens body 5.

[0071] exist Figure 12 In the example, the central axis C1 of each transmitting component 7 is not aligned with the optical axis AX1 of the corresponding lens body 5. Therefore, a portion of the end face of one of the transmitting components 7 is opposite to another lens body 5 adjacent to that transmitting component 7 in the Z-axis direction. As described above, a light-blocking component 13 is provided at the position where it abuts against two adjacent transmitting components 7, thus... Figure 12 As indicated by the dashed arrow, light traveling from the lens body 5 toward other transmitting elements 7 adjacent to the transmitting element 7 corresponding to the lens body 5 reaches the light-shielding member 13 and is absorbed. Therefore, the light path converged by two adjacent lens bodies 5 is separated by the light-shielding member 13.

[0072] As explained above, the optical component 1 of the image reading device 2 in Embodiment 3 includes a light-shielding component 13 disposed between the lens body 5 and the transmitting component 7. The light-shielding component 13 separates the optical path of light converged by adjacent lens bodies 5. As a result, even if the optical axis AX1 of the lens body 5 is not aligned with the central axis C1 of the transmitting component 7, light emitted from the lens body 5 is prevented from being received by other transmitting components 7 adjacent to the transmitting component 7 corresponding to the lens body 5 and other sensor elements 3 adjacent to the sensor element 3 corresponding to the lens body 5. Consequently, even if there is an error in the arrangement position of at least one of the lens body 5 and the transmitting component 7, the optical component 1 and the image reading device 2 that suppress the overlap of images formed by the lens body 5 can be obtained.

[0073] This disclosure is not limited to the examples of the embodiments described above. The arrangement of the constituent elements of the optical component 1 is not limited to the examples described above. Figure 13 As shown, the lens array 6 and the transmission component array 8 can also be arranged at intervals in the Z-axis direction and held in the frame 12.

[0074] The component array 8 can also be positioned closer to the object D being read than the lens array 6. More specifically, as... Figure 14 As shown, the optical component 1 may also include: a transmission component array 8 having a plurality of transmission components 7 that allow light incident from the object being read D onto one end face to exit from the other end face; and a lens array 6 having a plurality of lens bodies 5 that allow light exiting from the other end face of the transmission components 7 to converge and image onto each sensor element 3.

[0075] exist Figure 14 In the example, the end face of the other end of the transmitting component 7 of the transmitting component array 8 abuts against the end face of the lens body 5 of the lens array 6, but as Figure 15 As shown, the transmitting component 7 and the lens body 5 can also be arranged at intervals. The intervals between the multiple lens bodies 5 and the intervals between the multiple transmitting components 7 are greater than the arrangement error of the multiple lens bodies 5 and the multiple transmitting components 7.

[0076] like Figure 16 As shown, a light-shielding component 13 can also be provided between the transmissive component array 8 and the lens array 6. For example... Figure 17 As indicated by the dashed arrow, by providing the light-shielding component 13, light from the object being read, when passing through the transmitting component 7 without heading towards the lens body 5 corresponding to the transmitting component 7, reaches the light-shielding component 13 and is absorbed.

[0077] The arrangement of the lens body 5 and the transmitting component 7 is not limited to the examples described above. For example... Figure 18 and Figure 19 As shown, the lens bodies 5 can also be arranged at unequal intervals, while the transmission components 7 can be arranged at equal intervals.

[0078] The shapes of the lens body 5 and the transmitting component 7 are not limited to the examples described above. As an example, the transmitting component 7 may also have a cylindrical shape with a diameter larger than that of the lens body 5. In this case, such as... Figure 20 As shown, multiple transmitting elements 7 are arranged in abutting position, and multiple lens bodies 5 are simply arranged with intervals between them. The interval between the multiple lens bodies 5 only needs to be greater than the arrangement error of the multiple lens bodies 5 and the multiple transmitting elements 7. At this time, for the transmitting elements 7, as a treatment to suppress diffuse reflection of light incident from the outside to the side, it is only necessary to apply an adhesive mixed with carbon black to the transmitting elements 7. When applying the adhesive, it is preferable to apply it while suppressing the formation of air layers.

[0079] The material of the light-transmitting component 7 is not limited to the examples mentioned above. The light-transmitting component 7 can be formed by any component that allows light emitted from the light source 9 and used to read the object D to pass through. For example, if the light source 9 emits infrared light, ultraviolet light, or other light different from visible light, the light-transmitting component 7 can be formed by materials such as germanium, acrylic resin, or glass.

[0080] The material of the reflection suppression component 72 is not limited to the examples described above. The reflection suppression component 72 can be formed by any component that suppresses the reflection of light emitted from the light source 9 and used to read the object D being read.

[0081] In one implementation, the object to be read, D, moves relative to the fixed image reading device 2. However, the image reading device 2 can also move relative to the fixed object to be read, D, to read information about the object to be read. The transport of the object to be read, D, in the sub-scanning direction, i.e., the transport direction, can be achieved either by transporting the object to be read, D itself, or by moving the image reading device 2.

[0082] The position of the light source 9 is not limited to the examples described above. For example, the image reading device 2 may also have a light source 9 located on the positive Z-axis side of the transmissive plate 10. In this case, the object D to be read only needs to be transported between the light source 9 and the transmissive plate 10.

[0083] The light source 9 can also be located outside the image reading device 2. Specifically, the light source 9 can be located outside the frame 12 in either the case where reflected light reflected by the object being read D is converged through the optical component 1, or in the case where transmitted light that has passed through the object being read D is converged through the optical component 1.

[0084] The light emitted by the light source 9 passes through the light-transmitting plate 10, and the transmitted light is not limited to visible light. The light-transmitting plate 10 can be formed of a component that allows infrared or ultraviolet light to pass through. Even if it is formed of a component that does not allow visible light to pass through, it can still be used as the light-transmitting plate 10 as long as the light emitted by the light source 9 can pass through. If the light-transmitting plate 10 does not need to form a transport surface for the object D to be read, it may not be installed in the image reading device 2, specifically in the frame 12.

[0085] The structure of the light source 9 is not limited to the example described above. As an example, it can also have multiple LEDs (Light Emitting Diodes) and an LED substrate extending along the main scanning direction to form each LED. In this case, the multiple LEDs simply need to be arranged in an array along the main scanning direction. Figure 1 In the middle, there are two light sources 9 separated by optical components 1, but it is also possible to configure only one light source 9.

[0086] The location of the sensor substrate 11 is not limited to the examples above. It can be any location where the sensor array 4 on the sensor substrate 11 can receive the light converged by the lens array 6.

[0087] In this embodiment, a cylindrical refractive index distribution lens is used as the lens body 5, but the lens body 5 is arbitrary as long as it is the lens body of an upright equal-magnification optical system. As an example, a microlens can also be used as the lens body 5.

[0088] The construction of the light-transmitting component 7 is not limited to the examples described above; it can be arbitrary as long as light incident from one end face can exit from the other end face. As an example, the light-transmitting component 7 may also have a cylindrical shape with a through hole extending along the central axis C1. In other words, the light-transmitting component 7 may also have a cylindrical shape.

[0089] Various embodiments and modifications can be made without departing from the broad spirit and scope of this disclosure. Furthermore, the above-described embodiments are illustrative of this disclosure and are not intended to limit its scope. That is, the scope of this disclosure is indicated by the claims, not the embodiments. Moreover, various modifications implemented within the scope of the claims and their equivalents should be considered within the scope of this disclosure.

[0090] This application is based on Japanese Patent Application No. 2021-96275, filed on June 9, 2021. The description, claims, and drawings of Japanese Patent Application No. 2021-96275 are incorporated herein by reference in their entirety.

[0091] Explanation of reference numerals in the attached figures

[0092] D…Object to be read; 1…Optical component; 2…Image reading device; 3…Sensor element; 4…Sensor array; 5…Lens body; 6…Lens array; 56…Side plate; 7…Transmitting component; 71…Cylindrical component; 72…Reflection suppression component; 8…Transmitting component array; 78…Side plate; 9…Light source; 10…Transmitting plate; 11…Sensor substrate; 12…Frame; 12a, 12b…Openings; 13…Light-shielding component; AX1…Optical axis; C1…Central axis.

Claims

1. An optical component, characterized in that, have: A lens array having multiple lens bodies arranged in a row along the main scanning direction in a state of mutual contact, having a cylindrical shape, so that light from the object being read converges; Multiple transmitting elements, formed of elements with the same refractive index, are arranged adjacent to each other with gaps between them at positions closer to the object being read than the corresponding lens body or farther away from the object being read than the lens body. They have a cylindrical shape extending along the optical axis of the lens body, so that light incident from one end face can exit from the other end face. as well as At least one light-shielding component is disposed between the lens body and the transmitting component and between straight lines extending the optical axes of the adjacent lens bodies, thereby separating the optical paths of light incident on the adjacent lens bodies or the optical paths of light converged by the adjacent lens bodies. The diameter of the lens body is larger than the diameter of the corresponding transmitting component.

2. The optical component according to claim 1, characterized in that, It also includes a reflection suppression component, which is configured to abut against the side of the transmissive component to suppress reflection.

3. The optical component according to claim 1 or 2, characterized in that, The central axis of at least one of the transmitting components is aligned with the optical axis of the corresponding lens body.

4. The optical component according to claim 1 or 2, characterized in that, The transmitting component is positioned in a state where it abuts against the end of the optical axis of the lens body in the extending direction.

5. The optical component according to claim 1 or 2, characterized in that, The transmitting components are spaced apart at the ends of the lens body along the extension direction of the optical axis.

6. The optical component according to claim 1 or 2, characterized in that, The through-hole has a cylindrical shape with a through hole extending along the central axis.

7. An image reading device, characterized in that, have: The optical component according to any one of claims 1 to 6; and A sensor array having multiple sensor elements arranged according to each of the lens bodies of the lens array of the optical component, and receiving light focused by the lens bodies.

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