Optical line sensor

Abstract

This invention provides an optical line sensor capable of effectively preventing stray light from incident on each light-receiving element array. Multiple light-receiving lenses (111) are arranged in a linear configuration along the main scanning direction, allowing light from an illuminated object to pass through. An aperture member (113) is formed with multiple openings (113E) through which light passing through the multiple light-receiving lenses (111) passes. Multiple light-receiving elements constitute multiple light-receiving element arrays (12) extending along the main scanning direction, corresponding to the multiple openings (113E). A light-shielding block (114) is provided between the aperture member (113) and the multiple light-receiving element arrays (12), the light-shielding block (114) preventing light passing through openings (113E) adjacent to the openings (113E) corresponding to each light-receiving element array (12) from entering each light-receiving element array (12).

Description

Technical Field

[0001] This invention relates to an optical line sensor that uses a readout line extending in the main scanning direction to read objects that are moving relative to each other along the sub-scanning direction. Prior Technology

[0002] In an image reading device equipped with an optical line sensor, light shines from a light source toward an object, and reflected or transmitted light from the object is imaged on a reading line by a light-receiving lens, whereby it is received by a light-receiving element. Multiple light-receiving lenses are arranged in a row, and light passing through each lens is received by multiple light-receiving elements (for example, see Patent Document 1 below).

[0003] Typically, multiple light-receiving lenses are held integrally by a housing. In the example of Patent Document 1, the housing is composed of multiple housing components, each holding a light-receiving lens. Gaps are provided between the housing components to prevent displacement of their relative positions due to temperature changes.

[0004] However, in the traditional configuration described above, the large number of housing components and their complex shapes lead to higher manufacturing costs. Furthermore, the large number of components also complicates the assembly process.

[0005] Therefore, the applicant of this application proposes an optical line sensor with a small number of components and easy assembly, which has a pair of holding plates that hold multiple light-receiving lenses in the sub-scanning direction (see Patent Document 2 below).

[0006] Existing technical documents Patent documents Patent Document 1: International Publication No. 2021 / 049177 Patent Document 2: International Publication No. 2024 / 106058 Summary of the Invention

[0007] The problem that the invention aims to solve In the configuration disclosed in Patent Document 2 above, an aperture component is provided, which forms an opening for light passing through the light-receiving lens. A light-shielding portion is formed in the aperture component, which blocks a portion of the opening to prevent stray light from entering the light-receiving element array. Through this light-shielding portion, stray light that is inclined toward the opening in a direction relative to the optical axis and toward the sub-scanning direction can be effectively prevented from entering the light-receiving element array.

[0008] However, in the configuration disclosed in Patent Document 2 above, there is a situation where stray light incident on the light-receiving element array in a direction inclined towards the main scanning direction relative to the optical axis cannot be prevented. Specifically, there is a situation where light is incident on the light-receiving element array not through the opening corresponding to the light-receiving element array, but through the opening adjacent to that opening in the main scanning direction as stray light.

[0009] The present invention was made in view of the above-mentioned actual situation, and its purpose is to provide an optical line sensor that can effectively prevent stray light from incident on each light-receiving element array.

[0010] Methods for solving problems (1) The optical line sensor of the present invention is an optical line sensor that uses a readout line extending in the main scanning direction to read an object moving relative to it along the sub-scanning direction. The optical line sensor includes a plurality of light-receiving lenses, an aperture component, and a plurality of light-receiving elements. The plurality of light-receiving lenses are arranged in a linear shape along the main scanning direction to allow light from the illuminated object to pass through. The aperture component has a plurality of openings through which light passing through the plurality of light-receiving lenses passes. The plurality of light-receiving elements are arranged in a linear shape along the main scanning direction to receive light passing through the plurality of openings. The plurality of light-receiving elements constitute a plurality of light-receiving element arrays extending in the main scanning direction corresponding to the plurality of openings. The plurality of light-receiving element arrays are staggered in two columns of the readout line. A first light-shielding part is provided between the aperture component and the plurality of light-receiving element arrays. The first light-shielding part is used to prevent light passing through an opening adjacent to the opening corresponding to each light-receiving element array from entering each light-receiving element array.

[0011] With this configuration, the first light-shielding part, located between the aperture component and the array of multiple light-receiving elements, can prevent light passing through the opening adjacent to the opening corresponding to each light-receiving element array from entering each light-receiving element array. Therefore, stray light can be effectively prevented from incident on each light-receiving element array.

[0012] (2) The first light-shielding part may be provided in multiple ways corresponding to the plurality of openings. In this case, light passing through the opening adjacent to the opening corresponding to each light-receiving element array is blocked by the first light-shielding part provided corresponding to the adjacent opening.

[0013] With this configuration, stray light can be prevented from entering each light-receiving element array by means of a plurality of first light-shielding parts corresponding to each opening. In particular, stray light in the light passing through the opening adjacent to the opening corresponding to each light-receiving element array, which is inclined in the direction of the main scanning direction relative to the optical axis, is effectively blocked by the first light-shielding parts provided corresponding to the adjacent opening.

[0014] (3) Multiple first light-shielding parts may be staggered on the two columns of reading lines.

[0015] With this configuration, multiple first light-shielding portions can be staggered on two readout lines in correspondence with the staggered arrangement of multiple light-receiving element arrays. In this case, if each first light-shielding portion corresponding to each light-receiving element array is positioned offset relative to each light-receiving element array in the sub-scanning direction, stray light in the light passing through the opening adjacent to the opening corresponding to each light-receiving element array, which is inclined in the direction of the main scan direction and the sub-scanning direction relative to the optical axis, is effectively blocked by the first light-shielding portion provided corresponding to the adjacent opening.

[0016] (4) The width of the main scanning direction of the first light-shielding part is greater than the field of view width of the adjacent opening corresponding to the first light-shielding part at the setting position of the first light-shielding part, and less than the width of the light-receiving element array.

[0017] With this configuration, stray light in the range above the field of view of the adjacent opening in the main scanning direction can be effectively blocked by the first light-shielding part.

[0018] (5) A through hole is formed in the first light-shielding part, and the through hole extends along the light path of the light entering the light-receiving element array corresponding to the opening through the opening.

[0019] With this configuration, light passing through the opening toward the light-receiving element array corresponding to the opening is reliably guided to the light-receiving element array along the through hole, and stray light can be reliably blocked by the first light-shielding part constituting the inner peripheral surface of the through hole.

[0020] (6) When viewed from a direction orthogonal to the main scanning direction and the sub-scanning direction, the plurality of openings may be located between the two columns of readout lines. In this case, the through-hole may be formed as a cone shape that is inclined toward the sub-scanning direction relative to the direction orthogonal to the main scanning direction and the sub-scanning direction.

[0021] With this configuration, even when the light-receiving element array corresponding to the opening is positioned offset relative to the opening in the sub-scanning direction, light passing through the opening toward the light-receiving element array corresponding to the opening is reliably guided to the light-receiving element array along the conical through-hole formed to be inclined in the sub-scanning direction.

[0022] (7) The through hole can extend in a stepped manner along the inclined direction of the through hole.

[0023] With this configuration, light passing through the opening toward the light-receiving element array corresponding to the opening is reliably guided to the light-receiving element array along the through-hole extending in a stepped shape.

[0024] (8) The plurality of light-receiving lenses respectively constitute a telecentric optical system, and the width of the sub-scanning direction of each light-receiving lens is smaller than the width of the main scanning direction.

[0025] Based on this configuration, an optical line sensor with a large depth of field can be realized by using a telecentric optical system. Furthermore, since the width of the light-receiving lens in the sub-scanning direction is smaller than the width in the main scanning direction, the light-receiving lens can be arranged close together in the sub-scanning direction, resulting in a more compact optical line sensor.

[0026] (9) The plurality of openings can be formed in the shape of a frustum conical.

[0027] With this configuration, light from each light-receiving lens to the aperture component can be guided along the frustum-shaped opening.

[0028] (10) In the aperture component, a plurality of pinholes may be formed in a manner that is spaced apart from each opening for light to enter after passing through the plurality of openings.

[0029] With this configuration, light from each light-receiving lens to the aperture component can be guided along the opening and the pinhole.

[0030] (11) A second light-shielding part may be formed in the aperture component, which blocks a portion of the opening to prevent stray light from entering.

[0031] With this configuration, stray light can be prevented from entering the light path from each light-receiving lens to the aperture component by the second light-shielding part.

[0032] (12) The aperture component may be composed of a plurality of aperture components, each having the opening formed thereon. In this case, the optical line sensor may also include a pair of holding plates and a pair of sensor supports. The pair of holding plates clamp at least two of the plurality of light-receiving lenses and at least one of the plurality of aperture components in the sub-scanning direction. The pair of sensor supports hold the pair of holding plates, the at least two light-receiving lenses clamped between the pair of holding plates, and the at least one aperture component as a light-receiving lens array, and clamp the plurality of light-receiving lens arrays arranged in the main scanning direction in the sub-scanning direction. In addition, one side of the pair of holding plates is positioned on one side of the pair of sensor supports by a first positioning component, and the other side of the pair of holding plates is positioned on the other side of the pair of sensor supports by a second positioning component. The pair of sensor supports are connected to each other, thereby allowing the pair of holding plates to be positioned in an opposing state in the sub-scanning direction.

[0033] With this configuration, by using a pair of sensor supports to clamp multiple light-receiving lens arrays in the sub-scanning direction, at least two light-receiving lenses and at least one aperture component contained in each light-receiving lens array can be fixed between the pair of sensor supports. Therefore, even if a portion of the light-receiving lenses in any light-receiving lens array is defective, only that light-receiving lens array needs to be replaced, thus minimizing component waste.

[0034] Furthermore, since one side of the pair of retaining plates is positioned on one side of the pair of sensor supports via the first positioning component, and the other side of the pair of retaining plates is positioned on the other side of the pair of sensor supports via the second positioning component, the assembly operation is easy, and each light-receiving lens array can be accurately positioned and fixed between the pair of sensor supports. Thus, multiple light-receiving lenses and multiple aperture components can be easily and accurately positioned.

[0035] (13) Each of the pair of retaining plates may have a threaded hole for fixing. In this case, each of the pair of sensor brackets may have a through hole formed at a position opposite to the threaded hole for fixing. In addition, a first fixing screw inserted through the through hole formed on one side of the pair of sensor brackets is screwed into the threaded hole for fixing formed on one side of the pair of retaining plates, thereby fixing one side of the pair of retaining plates to one side of the pair of sensor brackets, and a second fixing screw inserted through the through hole formed on the other side of the pair of sensor brackets is screwed into the threaded hole for fixing formed on the other side of the pair of retaining plates, thereby fixing the other side of the pair of retaining plates to the other side of the pair of sensor brackets.

[0036] With this configuration, for each light-receiving lens array, one side of a pair of retaining plates is fixed to one side of a pair of sensor supports using a first fixing screw, and the other side of a pair of retaining plates is fixed to the other side of a pair of sensor supports using a second fixing screw. Furthermore, the pair of sensor supports are connected to each other, thereby enabling the pair of sensor supports to clamp multiple light-receiving lens arrays in the sub-scanning direction. This allows for more accurate positioning of multiple light-receiving lenses and multiple aperture components.

[0037] (14) The optical line sensor may also include a spacer. The spacer is disposed between the pair of sensor supports to keep the distance between the pair of sensor supports constant when the plurality of light-receiving lens arrays are clamped in the sub-scanning direction using the pair of sensor supports.

[0038] With this configuration, when a pair of sensor supports are connected to each other, the distance between the pair of sensor supports can be kept constant by the spacer, thus enabling more accurate positioning of multiple light-receiving lenses and multiple aperture components.

[0039] (15) The optical line sensor may further include a light-receiving substrate on which the plurality of light-receiving elements are mounted. In this case, each of the pair of sensor supports may be formed in an L-shape having a first plate portion and a second plate portion, the first plate portion being opposite to the plurality of light-receiving lens arrays, and the second plate portion extending from one end of the first plate portion toward a side opposite to the plurality of light-receiving lens arrays. Additionally, the light-receiving substrate may be mounted across the pair of sensor supports on the side of the second plate portion.

[0040] With this configuration, a light-receiving substrate can be mounted across the pair of sensor supports on the second plate side, based on positioning multiple light-receiving lenses and multiple aperture components between the first plates of a pair of sensor supports. Therefore, it is possible to accurately position the multiple light-receiving lenses and multiple aperture components relative to the multiple light-receiving elements mounted on the light-receiving substrate.

[0041] (16) The optical axes of the plurality of light-receiving lenses may be located on the center line between the two columns of reading lines.

[0042] With this configuration, in which the optical axes of each light-receiving lens are located on the center line between the two rows of reading lines, multiple light-receiving lenses, multiple aperture components, and multiple light-receiving element arrays can be accurately positioned relative to each other.

[0043] (17) The pair of sensor holders may be arranged in multiple configurations in the main scanning direction.

[0044] With this configuration, by arranging multiple pairs of sensor holders in the main scanning direction, the reading range in the main scanning direction can be expanded.

[0045] (18) The optical line sensor may also include a third light-shielding part that covers the gap between adjacent aperture components.

[0046] With this configuration, stray light can be blocked from entering through the gap between adjacent aperture components by the third light-shielding part, thus effectively preventing stray light from incident on each light-receiving element array.

[0047] (19) The optical line sensor may also include a cover component arranged such that the end faces of the light incident sides of the pair of retaining plates are arranged across each other.

[0048] With this configuration, foreign matter can be prevented from entering between the pair of retaining plates by the cover component.

[0049] (20) At least one injection hole may be formed in the pair of retaining plates at a position opposite to the light-receiving lens. In this case, the pair of retaining plates and the at least two light-receiving lenses may be fixed by adhesive injected into the at least one injection hole.

[0050] With this configuration, each light-receiving lens can be reliably fixed to the pair of retaining plates by injecting adhesive into at least one injection hole formed in the pair of retaining plates.

[0051] (21) At least one first adjustment threaded hole may be formed in the pair of retaining plates at a position opposite to the light-receiving lens. In this case, the angle of the light-receiving lens relative to the pair of retaining plates can be adjusted by a first adjustment screw that is screwed into the at least one first adjustment threaded hole and whose front end abuts against the light-receiving lens.

[0052] With this configuration, the angle of the light-receiving lens relative to a pair of retaining plates can be finely adjusted by the first adjusting screw, thus making it easy and accurate to adjust the optical axis of the light-receiving lens.

[0053] (22) At least one second adjustment threaded hole may be formed in the pair of sensor brackets at a position opposite to the retaining plate. In this case, the angle of the retaining plate relative to the pair of sensor brackets can be adjusted by a second adjustment screw that is screwed into the at least one second adjustment threaded hole and whose front end abuts against the retaining plate.

[0054] With this configuration, the angle of the retaining plate relative to the pair of sensor supports can be finely adjusted by the second adjusting screw, so that even after each light-receiving lens array is fixed between the pair of sensor supports, the optical axis of the light-receiving lens can be easily and accurately adjusted.

[0055] (23) The pair of retaining plates have a fitting portion for fitting together and connecting the pair of retaining plates to each other.

[0056] With this configuration, a pair of retaining plates are reliably connected to each other through a fitting part, thus enabling more accurate positioning of multiple light-receiving lenses and multiple aperture components.

[0057] The effects of the invention According to the present invention, stray light can be effectively prevented from incident on each light-receiving element array. Simple Explanation of the Diagram

[0058] Figure 1 is a cross-sectional view showing an example of the configuration of an optical line sensor according to an embodiment of the present invention. Figure 2 is an exploded perspective view showing an example of the configuration of the illumination optical system in the optical line sensor of Figure 1. Figure 3 is a perspective view of the light-receiving lens array involved in the first embodiment. Figure 4 is an exploded perspective view of the light-receiving lens array involved in the first embodiment. Figure 5 is a perspective view of the aperture component involved in the first embodiment. Figure 6 is a perspective view of the light-receiving lens array involved in the second embodiment. Figure 7 is an exploded perspective view of the light-receiving lens array involved in the second embodiment. Figure 8A is a perspective view of the aperture component involved in the second embodiment. Figure 8B is a perspective view showing a modified example of the aperture component involved in the second embodiment. Figure 9 is a perspective view illustrating the manufacturing method of the light-receiving lens array involved in the second embodiment. Figure 10A is a schematic diagram illustrating the positional relationship between the light-receiving lens and the light-receiving element array, showing the trapezoidal light-receiving lens involved in the second embodiment shown in Figures 6 and 7. Figure 10B is a schematic diagram illustrating the positional relationship between the light-receiving lens and the light-receiving element array, showing the case of the light-receiving lens involved in the modified example. Figure 11A is a diagram showing the reception of normal light (not stray light) incident on the aperture component through the light-receiving lens and emitted from the opening by the light-receiving element array. Figure 11B is a diagram illustrating a specific example of stray light incident on an array of light-receiving elements in a direction inclined to the X direction relative to the Z direction. Figure 11C is a diagram illustrating a specific example of stray light incident on an array of light-receiving elements in a direction inclined to the X direction relative to the Z direction. Figure 11D is a diagram illustrating a specific example of stray light incident on an array of light-receiving elements in a direction inclined to the X direction relative to the Z direction. Figure 12A is a cross-sectional view along the XY plane of an optical line sensor with a light-shielding block. Figure 12B is a cross-sectional view along the XZ plane of an optical line sensor with a light-shielding block. Figure 12C is a cross-sectional view along the YZ plane of an optical line sensor with a light-shielding block, showing the cross-section at the location of the light-receiving lens. Figure 12D is a cross-sectional view along the YZ plane of an optical line sensor with a light-shielding block, showing the cross-section at the location of the light-receiving lens. Figure 13A is a diagram of the retaining plate viewed from the light-receiving lens side along the Y direction. Figure 13B is a diagram of the retaining plate viewed from the side opposite to the light-receiving lens side along the Y direction. Figure 14A is a cross-sectional view of the optical line sensor along the YZ plane, showing the cross-section obtained by cutting at the location of the positioning hole. Figure 14B is a cross-sectional view of the optical line sensor along the YZ plane, showing the cross-section obtained by cutting at the location of the fixing threaded hole. Figure 15 is a cross-sectional view of the optical line sensor along the YZ plane, showing a cross-section of one end of a pair of sensor supports in the X direction. Figure 16 is a schematic top view showing an example of an elongated optical line sensor. Figure 17A is a diagram showing the situation corresponding to Figure 11B, which prevents stray light from entering the light-receiving element array. Figure 17B is a cross-sectional view along the YZ plane at the location of the light-receiving lens in Figure 17A, showing the situation where stray light toward the light-receiving element array is blocked by the light-blocking block. Figure 17C is a cross-sectional view along the YZ plane at the location of the light-receiving lens in Figure 17A, showing the case where normal light is incident on the light-receiving element array. Figure 18A is a diagram showing the situation corresponding to Figure 11C where stray light is prevented from entering the light-receiving element array. Figure 18B is a cross-sectional view along the YZ plane at the location of the light-receiving lens in Figure 18A, showing the situation where stray light toward the light-receiving element array is blocked by the light-shielding block. Figure 18C is a cross-sectional view along the YZ plane at the location of the light-receiving lens in Figure 18A, showing the situation where normal light is incident on the light-receiving element array. Figure 19A is a diagram showing the situation corresponding to Figure 11D regarding preventing stray light from entering the light-receiving element array. Figure 19B is a cross-sectional view along the YZ plane at the location of the light-receiving lens in Figure 19A, showing the situation where stray light toward the light-receiving element array is blocked by the light-shielding block. Figure 19C is a cross-sectional view along the YZ plane at the location of the light-receiving lens in Figure 19A, showing the situation where normal light is incident on the light-receiving element array. Figure 20A is a diagram illustrating a modified example of the light-shielding block. Figure 20B is a cross-sectional view along the YZ plane at the location of the light-receiving lens in Figure 20A, showing the situation where normal light is incident on the light-receiving element array. Figure 20C is a cross-sectional view along the YZ plane at the location of the light-receiving lens adjacent to the light-receiving lens in Figure 20A, showing the case where normal light is incident on the light-receiving element array. Figure 20D is a diagram illustrating a modified example of the through hole in the light-shielding block shown in Figure 20B. Figure 20E is a diagram illustrating a modified example of the through hole in the light-shielding block shown in Figure 20C. Figure 21A is a diagram illustrating another variation of the light-shielding block. Figure 21B is a cross-sectional view along the YZ plane at the location of the light-receiving lens in Figure 21A, showing the situation where normal light is incident on the light-receiving element array. Figure 21C is a cross-sectional view along the YZ plane at the location of the light-receiving lens adjacent to the light-receiving lens in Figure 21A, showing the case where normal light is incident on the light-receiving element array. Implementation

[0059] 1. Overall structure of the optical line sensor Figure 1 is a cross-sectional view showing an example of the configuration of an optical line sensor according to an embodiment of the present invention. Figure 1 shows a cross-sectional view near the center portion along the long side of the optical line sensor. Figure 2 is an exploded perspective view showing an example of the configuration of the illumination optical system in the optical line sensor of Figure 1. In Figure 2, the X direction is the main scanning direction, and the Y direction is the sub-scanning direction. The Z direction is orthogonal to both the X and Y directions.

[0060] This optical line sensor is a contact image sensor (CIS), primarily used to illuminate thin objects such as printed materials and films, and to receive reflected or transmitted light from the object using light-receiving elements. In the optical line sensor shown in Figure 1, two housings 16 are arranged opposite each other across a focal plane 20. Each housing 16 contains a linear light source 10 for illuminating an object located on the focal plane 20. One housing 16 contains a light-receiving lens array 11 and a light-receiving element array 12. Light from the illuminated object is guided by the light-receiving lens array 11 to the light-receiving element array 12. The light-receiving lens array 11 images the light from the object onto the light-receiving element array 12 along a reading line extending in the X direction. In the optical line sensor shown in Figure 1, with the focal plane 20 as a reference, one of the two light source units 10 is positioned on the side of the light-receiving element array 12, and the other is positioned on the opposite side. In addition, protective glass 14 is provided at the openings on the focal plane 20 side of each housing 16.

[0061] The light-receiving element array 12 is mounted on a substrate 13 fixed to one side of a housing 16. Light passing through the light-receiving lens array 11 is received by the light-receiving surface 12A of the light-receiving element array 12, and a signal corresponding to the amount of light received is output from the light-receiving element array 12. An object is transported along the focal plane 20 in the Y direction, thereby continuously receiving light from the object by the light-receiving element array 12, and an image of the object is obtained based on the output signal from the light-receiving element array 12. In this way, the object transported in the Y direction is read by the light-receiving element array 12 extending in the X direction using the readout line formed by the light-receiving surface 12A of the light-receiving element array 12. However, the configuration is not limited to transporting an object; it can also be a configuration where the optical line sensor moves relative to a stationary object, thereby causing the object to move relative to it.

[0062] An ultraviolet (UV) cutoff filter 15 that blocks ultraviolet light from entering the light-receiving element array 12 can be provided at any position from the focal plane 20 to the light-receiving element array 12. In addition, a color filter 18 that allows visible light of a specific wavelength range to pass through can be provided between the light-receiving element array 12 and the UV cutoff filter 15.

[0063] In the examples shown in Figures 1 and 2, the light source 10 includes: a transparent light guide 101 extending along its long side (X direction); a light source 103 disposed near one end face along its long side; and a cover member 102 for holding the sides of the light guide 101. Light emitted from the light source 103, after incident on the light guide 101, propagates within the light guide 101 while being appropriately reflected by the light diffusion pattern P, and exits from the light emitting surface in the direction of the arrow, becoming a linear illumination beam to illuminate the object.

[0064] 2. First embodiment of the light-receiving lens array Figures 3 to 5 are diagrams illustrating a first embodiment of the light-receiving lens array 11. Figure 3 is a perspective view of the light-receiving lens array 11 according to the first embodiment. Figure 4 is an exploded perspective view of the light-receiving lens array 11 according to the first embodiment. Figure 5 is a perspective view of the aperture component 113 according to the first embodiment.

[0065] The light-receiving lens array 11 includes a plurality of light-receiving lenses 111 and a pair of retaining plates 112. The plurality of light-receiving lenses 111 are arranged linearly along the X direction. More specifically, the optical axes of the plurality of light-receiving lenses 111 are all located on the same plane and are parallel to each other. The pair of retaining plates 112 are rectangular thin plate components that extend parallel to each other along the X direction. The plurality of light-receiving lenses 111 are held between the pair of retaining plates 112 in the Y direction. When it is desired to increase the X-direction dimension of the retaining plates 112, it is preferable to choose a material with a small coefficient of linear expansion in order to suppress length changes due to temperature variations. For example, glass epoxy laminate has a small coefficient of linear expansion of about 16 ppm and a low specific gravity, which can suppress weight, and is therefore preferred.

[0066] Each light-receiving lens 111 is rectangular when viewed from above (Z direction). One end face (first surface 111A) and the other end face (second surface 111B) in the Y direction are both composed of flat surfaces. The incident surface (the surface on the side of the focal plane 20) and the exit surface (the surface opposite to the incident surface) of each light-receiving lens 111 are, for example, composed of convex curved surfaces, which serve to image the light incident on each light-receiving lens 111 onto the light-receiving surface 12A.

[0067] The width in the Y direction of each light-receiving lens 111 (the interval between the first surface 111A and the second surface 111B) is the same. Therefore, by using a pair of retaining plates 112 to integrally clamp multiple light-receiving lenses 111, the first surface 111A of each light-receiving lens 111 can abut against one side of the pair of retaining plates 112 (retaining plate 112A), and the second surface 111B of each light-receiving lens 111 can abut against the other side of the pair of retaining plates 112 (retaining plate 112B).

[0068] In this embodiment, the light-receiving lens array 11 includes a plurality of aperture members 113. Each aperture member 113 corresponds one-to-one with each light-receiving lens 111 and is arranged separately from each light-receiving lens 111 in the optical axis direction. Light from the illuminated object, after passing through each light-receiving lens 111, is guided to the light-receiving element array 12 through the opening 113A formed in the corresponding aperture member 113. However, it is also possible to not provide a plurality of aperture members 113 each having an opening 113A, but to have a plurality of openings 113A formed in a single aperture member 113.

[0069] As shown in Figure 5, the opening 113A formed in the aperture component 113 extends through the aperture component 113 in the optical axis direction and is formed into a frustum-shaped cone that tapers towards the front end from the light-receiving lens 111 side towards the light-receiving element array 12 side. By aligning the Z-direction (optical axis direction) position of the tapered front end of the opening 113A with the image-side focal point of the light-receiving lens 111, the aperture component 113 can form a telecentric optical system together with multiple light-receiving lenses 111. In this case, it is preferable to make the apex angle of the frustum-shaped opening 113A slightly larger than the opening angle of the light-receiving lens 111. As a result, the image formed by the light-receiving lens 111 will not become vignetted, and stray light can be effectively reduced.

[0070] The width of each aperture component 113 in the Y direction is consistent with the spacing between the first surface 111A and the second surface 111B of each light-receiving lens 111. That is, the width of each aperture component 113 in the Y direction is consistent with the width of each light-receiving lens 111 in the Y direction. Therefore, when multiple light-receiving lenses 111 are integrally clamped by a pair of retaining plates 112, the two end faces of each aperture component 113 in the Y direction respectively abut against the pair of retaining plates 112.

[0071] In this embodiment, the first surface 111A of each light-receiving lens 111 is bonded to one of the retaining plates 112A, and the second surface 111B is bonded to the other retaining plate 112B. Similarly, one surface of each aperture component 113 in the Y direction is bonded to one of the retaining plates 112A, and the other surface in the Y direction is bonded to the other retaining plate 112B. The bonding between the components can be done using general adhesives or double-sided tape. However, each aperture component 113 may not be a separate component from the pair of retaining plates 112, but may be integrally formed with either retaining plate 112.

[0072] Each light-receiving lens 111 can be abutted against a pair of retaining plates 112 without being glued. For example, a portion of the first surface 111A and the second surface 111B of the light-receiving lens 111 can be formed with a protrusion, and a corresponding recess can be formed on the pair of retaining plates 112. With each protrusion inserted into each recess, the pair of retaining plates 112 can be fixed to each other by a fastener, thereby clamping each light-receiving lens 111 in the Y direction by the pair of retaining plates 112.

[0073] The light-receiving lenses 111 are preferably arranged in a manner that prevents them from contacting each other. That is, multiple light-receiving lenses 111 can be arranged spatially apart from each other in a manner that prevents adjacent light-receiving lenses 111 in the X direction from contacting each other. In this case, it is preferable to provide an elastic member with light-shielding and low-reflectivity in the space. Examples of elastic members include polyurethane, but it is not limited to this. Elastic members can also be formed between each light-receiving lens 111 by filling with an elastic adhesive.

[0074] 3. Second embodiment of the light-receiving lens array Figures 6 to 8A are diagrams illustrating a second embodiment of the light-receiving lens array 11. Figure 6 is a perspective view of the light-receiving lens array 11 according to the second embodiment. Figure 7 is an exploded perspective view of the light-receiving lens array 11 according to the second embodiment. Figure 8A is a perspective view of the aperture component 113 according to the second embodiment.

[0075] The light-receiving lens array 11 includes a plurality of light-receiving lenses 111 and a pair of holding plates 112. The plurality of light-receiving lenses 111 are arranged in a linear configuration along the X direction. More specifically, the optical axes of the plurality of light-receiving lenses 111 are all located on the same plane and are parallel to each other. The pair of holding plates 112 are rectangular thin plate components that extend parallel to each other along the X direction. The plurality of light-receiving lenses 111 are held between the pair of holding plates 112 in the Y direction.

[0076] Each light-receiving lens 111 is trapezoidal when viewed from above (Z-direction). One end face (first surface 111A) and the other end face (second surface 111B) in the Y-direction are both composed of flat surfaces. The width of the second surface 111B in the X-direction is smaller than that of the first surface 111A, and the second surface 111B is opposite the central portion of the first surface 111A in the X-direction. The first surface 111A and the second surface 111B are connected by a pair of inclined surfaces 111C. That is, one end of the first surface 111A in the X-direction is connected to one end of the second surface 111B in the X-direction via one inclined surface 111C, and the other end of the first surface 111A in the X-direction is connected to the other end of the second surface 111B in the X-direction via the other inclined surface 111C.

[0077] The incident surface (the surface on the side of the focal plane 20) and the exit surface (the surface opposite to the incident surface) of each light-receiving lens 111 are, for example, convex curved surfaces, which serve to image the light incident on each light-receiving lens 111 onto the light-receiving surface 12A. In this example, each light-receiving lens 111 is composed of two trapezoidal lenses (biconvex lens and concave-convex lens) arranged along the optical axis in the Z direction, but it is not limited to this configuration. Each light-receiving lens 111 may also be composed of a single trapezoidal lens, or it may be composed of three or more trapezoidal lenses.

[0078] As shown in Figure 7, the plurality of light-receiving lenses 111 include a portion of a light-receiving lens 120 mounted on one of a pair of retaining plates 112 (retaining plate 112A) and the remaining portion of a light-receiving lens 130 mounted on the other of the pair of retaining plates 112 (retaining plate 112B). The first surface 111A of each light-receiving lens 111 is mounted on each retaining plate 112. That is, the manufacturing method of the light-receiving lens array 11 in this example includes: a first lens mounting step, mounting the first surface 111A of a portion of the plurality of light-receiving lenses 111 (light-receiving lens 120) on one of the pair of retaining plates 112 (retaining plate 112A); and a second lens mounting step, mounting the first surface 111A of the remaining portion of the plurality of light-receiving lenses 111 (light-receiving lens 130) on the other of the pair of retaining plates 112 (retaining plate 112B).

[0079] In the first lens mounting step, half of each of the plurality of light-receiving lenses 120 (light-receiving lenses 111) is mounted in the X direction at every other half onto one side of a pair of retaining plates 112 (retaining plate 112A). In the second lens mounting step, the remaining half of each of the plurality of light-receiving lenses 111 (light-receiving lenses 130) is mounted in the X direction at every other half onto the other side of a pair of retaining plates 112 (retaining plate 112B). Essentially, since the first lens mounting step and the second lens mounting step are the same operation, workability can be improved and the number of assembly fixtures can be reduced.

[0080] As described above, after each half of the plurality of light-receiving lenses 111 is mounted on each of a pair of retaining plates 112, the pair of retaining plates 112 are positioned opposite each other, and the light-receiving lenses 111 are clamped in the Y direction by the pair of retaining plates 112, thereby fixing the light-receiving lenses 111 between the pair of retaining plates 112 (fixing step). In this fixing step, as shown in Figures 6 and 7, a plurality of light-receiving lenses (light-receiving lenses 130) mounted on the other side of the pair of retaining plates 112 (retaining plate 112B) enter between a plurality of light-receiving lenses 111 (light-receiving lenses 120) mounted on one side of the pair of retaining plates 112 (retaining plate 112A). In this state, the inclined surfaces 111C of adjacent light-receiving lenses 111 (light-receiving lenses 120 and light-receiving lenses 130) in the X direction are opposite each other.

[0081] The width in the Y direction of each light-receiving lens 111 (the interval between the first surface 111A and the second surface 111B) is the same. Therefore, by using a pair of retaining plates 112 to integrally clamp multiple light-receiving lenses 111, the first surface 111A of each light-receiving lens 111 can abut against one side of the pair of retaining plates 112 (the light-receiving lens 120 is the retaining plate 112A, and the light-receiving lens 130 is the retaining plate 112B), and the second surface 111B of each light-receiving lens 111 can abut against the other side of the pair of retaining plates 112 (the light-receiving lens 120 is the retaining plate 112B, and the light-receiving lens 130 is the retaining plate 112A).

[0082] In this embodiment, the light-receiving lens array 11 includes a plurality of aperture components 113. Each aperture component 113 corresponds one-to-one with each light-receiving lens 111 and is arranged separately from each light-receiving lens 111 in the optical axis direction. Light from the illuminated object, after passing through each light-receiving lens 111, is guided to the light-receiving element array 12 through the opening 113A formed in the corresponding aperture component 113.

[0083] As shown in Figure 8A, the opening 113A formed in the aperture component 113 extends through the aperture component 113 in the optical axis direction and is formed into a frustum-shaped cone that tapers towards the front end from the light-receiving lens 111 side towards the light-receiving element array 12 side. By aligning the Z-direction (optical axis direction) position of the tapered front end of the opening 113A with the image-side focal point of the light-receiving lens 111, the aperture component 113 can form a telecentric optical system together with multiple light-receiving lenses 111. In this case, it is preferable to make the apex angle of the frustum-shaped opening 113A slightly larger than the opening angle of the light-receiving lens 111. As a result, the image formed by the light-receiving lens 111 will not become vignetted, and stray light can be effectively reduced.

[0084] In this example, as shown in FIG8A, a light-shielding wall (second light-shielding portion) 113B is formed in the aperture component 113 to block a portion of the opening 113A and prevent stray light from entering. In this example, one half (the portion through which stray light passes) of the frustum-shaped opening 113A in the Y direction is blocked, thereby forming a semi-circular frustum-shaped opening 113A with a semi-circular arc surface and a flat surface. A recess 113C extending along the optical axis is formed on the aforementioned flat surface constituting the light-shielding wall 113B. The recess 113C can be semi-cylindrical as shown in FIG8A.

[0085] The width of each aperture component 113 in the Y direction is consistent with the spacing between the first surface 111A and the second surface 111B of each light-receiving lens 111. That is, the width of each aperture component 113 in the Y direction is consistent with the width of each light-receiving lens 111 in the Y direction. Therefore, when multiple light-receiving lenses 111 are integrally clamped by a pair of retaining plates 112, the two end faces of each aperture component 113 in the Y direction respectively abut against the pair of retaining plates 112.

[0086] In this embodiment, the first surface 111A of the light-receiving lens 120 is bonded to the holding plate 112A, and the second surface 111B is bonded to the holding plate 112B. Similarly, the first surface 111A of the light-receiving lens 130 is bonded to the holding plate 112B, and the second surface 111B is bonded to the holding plate 112A. Likewise, one surface of each aperture component 113 in the Y direction is bonded to one holding plate 112A, and the other surface in the Y direction is bonded to the other holding plate 112B. The bonding between the components can be done using general adhesives or double-sided tape. However, each aperture component 113 may not be a separate component from the pair of holding plates 112, but may be integrally formed with either holding plate 112.

[0087] Each light-receiving lens 111 can be abutted against a pair of retaining plates 112 without being glued. For example, a portion of the first surface 111A and the second surface 111B of the light-receiving lens 111 can be formed with a protrusion, and a corresponding recess can be formed on the pair of retaining plates 112. With each protrusion inserted into each recess, the pair of retaining plates 112 can be fixed to each other by a fastener, thereby clamping each light-receiving lens 111 in the Y direction by the pair of retaining plates 112.

[0088] The light-receiving lenses 111 are preferably arranged in a manner that prevents them from contacting each other. That is, the plurality of light-receiving lenses 111 can be arranged spatially apart from each other in such a manner that the inclined surfaces 111C of adjacent light-receiving lenses 111 in the X direction do not contact each other. In this case, it is preferable to provide an elastic member with light-shielding and low reflectivity in the space. Examples of elastic members include polyurethane, but it is not limited to this. Elastic members can also be formed between the light-receiving lenses 111 by filling them with an elastic adhesive.

[0089] Figure 8B is a perspective view showing a modified example of the aperture component 113 according to the second embodiment. In the example of Figure 8A, the aperture component 113 is described as being constructed of a quadrangular prism-shaped component with a frustum-shaped opening 113A formed through the component. In contrast, in the example of Figure 8B, the aperture component 113 is constructed of a rectangular frame with two openings 113D and 113E formed in a mutually opposing manner. That is, the aperture component 113 of Figure 8B is a hollow component, and light incident from opening 113D passes through the internal space of the aperture component 113 and exits from opening 113E.

[0090] Specifically, the aperture component 113 of FIG8B has an upper panel and a lower panel extending horizontally in a manner opposite each other in the vertical direction, and a pair of side panels extending vertically in a manner connecting the two ends of these upper and lower panels to each other, having a shape that is framed as rectangular when viewed horizontally. The upper and lower panels are arranged parallel to each other with a gap between them, with an opening 113D formed in the upper panel and an opening 113E formed in the lower panel. Thus, the openings 113D and 113E are formed to be opposite each other with a gap between them.

[0091] The opening 113E is positioned in the Z direction (optical axis direction) coinciding with the image-side focal point of the receiving lens 111. Thus, the aperture component 113, together with the multiple receiving lenses 111, constitutes a telecentric optical system. As shown in FIG8B, a light-shielding wall (second light-shielding portion) 113B is formed in the aperture component 113 to block a portion of the opening 113D, preventing stray light from entering. In this example, one half (the portion through which stray light passes) of the circular opening in the Y direction is blocked, thereby forming a semi-circular opening 113D with a semi-circular arc surface and a flat surface. Similar to the example in FIG8A, a semi-circular recess extending along the optical axis can be formed on the aforementioned flat surface constituting the light-shielding wall 113B. The opening 113E is a circular pinhole smaller than the opening 113D, allowing light passing through the opening 113D to enter. In this case, it is preferable that the apex angle of the imaginary frustum-shaped cones formed by openings 113D and 113E is slightly larger than the opening angle of the light-receiving lens 111. As a result, the image formed by the light-receiving lens 111 will not become vignetted, and stray light can be effectively reduced.

[0092] As in the examples of Figures 10A or 10B described later, when the optical axes of each light-receiving lens 111 are offset in the Y direction relative to the light-receiving element array 12 (readout line L), stray light emitted from adjacent light-receiving lenses 111 and inclined towards the opening 113E in a direction inclined in the Y direction relative to the Z direction (a direction orthogonal to the X and Y directions) can be effectively blocked by the light-shielding wall 113B. In this case, a partition plate can be omitted between adjacent light-receiving lenses 111 and aperture components 113. Furthermore, the side panels of the aperture components 113 can be omitted, and the aperture components 113 can be composed of separate upper and lower panels. However, if the aperture components 113 are formed as a frame as in Figure 8B, the aperture components 113 become a single unit, which is easy to process.

[0093] Figure 9 is a perspective view illustrating the manufacturing method of the light-receiving lens array 11 according to the second embodiment. When manufacturing the light-receiving lens array 11, with the holding plate 112 placed on the mounting stage 200, each light-receiving lens 111 and each aperture component 113 are mounted on the holding plate 112 (first lens mounting step and second lens mounting step).

[0094] The mounting platform 200 includes a first positioning part 201 and a pressing mechanism 202. The first positioning part 201 is composed of multiple protrusions, and the retaining plate 112 can be positioned by abutting the side edge of the retaining plate 112 against the side of the first positioning part 201. With the retaining plate 112 positioned, the pressing mechanism 202 presses the retaining plate 112, thereby fixing the retaining plate 112 to the mounting platform 200. In this example, a pair of pressing mechanisms 202 are provided, which can press the two ends of the retaining plate 112 in the long side direction. However, the first positioning part 201 is not limited to being composed of protrusions, for example, it can also be composed of recesses.

[0095] In the first lens mounting step and the second lens mounting step, a plurality of light-receiving lenses 111 and aperture components 113 are mounted on a pair of retaining plates 112 using an optical axis alignment fixture 300. The optical axis alignment fixture 300 is a fixture used to position the light-receiving lenses 111 and aperture components 113 in a specified position and to align their optical axes.

[0096] A second positioning portion 203 for positioning the optical axis alignment fixture 300 is formed on the mounting stage 200. The second positioning portion 203 is composed of a plurality of protrusions. Specifically, a plurality of pairs of protrusions corresponding to a pair of light-receiving lenses 111 and aperture components 113 are arranged along the X direction. The X-direction spacing (pitch) between the plurality of pairs of protrusions is consistent with the X-direction spacing (pitch) when each light-receiving lens 111 and each aperture component 113 is mounted on the holding plate 112. However, the second positioning portion 203 is not limited to being composed of protrusions; for example, it may also be composed of recesses.

[0097] The optical axis alignment fixture 300 is a plate-shaped component used when placed on a retaining plate 112 mounted on a mounting stage 200. The optical axis alignment fixture 300 has a first through hole 301, a second through hole 302, and a third through hole 303.

[0098] The first through hole 301 is a hole for inserting the light-receiving lens 111, and has a shape that abuts against the positioning part of the light-receiving lens 111 for positioning. The second through hole 302 is a hole for inserting the aperture member 113, and has a shape that abuts against the positioning part of the aperture member 113 for positioning. The third through hole 303 has a shape corresponding to a pair of protrusions constituting the second positioning part 203, and a pair of third through holes 303 are formed that are separated from the pair of protrusions at the same interval.

[0099] When manufacturing the light-receiving lens array 11, with the holding plate 112 fixed to the mounting stage 200 by the pressing mechanism 202, the optical axis alignment fixture 300 is placed on the holding plate 112. At this time, multiple pairs of protrusions constituting the second positioning part 203 are sequentially inserted into a pair of third through holes 303 of the optical axis alignment fixture 300.

[0100] Then, with each pair of protrusions inserted into a pair of third through holes 303 of the optical axis alignment fixture 300, the light-receiving lens 111 is inserted into and positioned in the first through hole 301 and mounted on the retaining plate 112, and the aperture component 113 is inserted into and positioned in the second through hole 302 and mounted on the retaining plate 112. At this time, the light-receiving lens 111 is inserted into the first through hole 301 with adhesive applied to the contact surface with the retaining plate 112. Similarly, the aperture component 113 is inserted into the second through hole 302 with adhesive applied to the contact surface with the retaining plate 112. Alternatively, if adhesive is applied to one side of the retaining plate 112 or double-sided tape is applied beforehand, the work of applying adhesive to the light-receiving lens 111 and the aperture component 113 can be omitted.

[0101] In this way, the light-receiving lens 111 and the aperture component 113 can be mounted on the retaining plate 112 at positions corresponding to each pair of protrusions constituting the second positioning part 203. Thus, as shown in FIG7, a plurality of light-receiving lenses 111 and a plurality of aperture components 113 are mounted on each retaining plate 112 at intervals in the X direction.

[0102] 4. Positional relationship between the light-receiving lens and the light-receiving element array Figures 10A and 10B are schematic diagrams illustrating the positional relationship between the light-receiving lens 111 and the light-receiving element array 12. Figure 10A shows the trapezoidal light-receiving lens 111 according to the second embodiment shown in Figures 6 and 7. On the other hand, Figure 10B shows the light-receiving lens 111 according to the modified example.

[0103] In Figures 10A and 10B, a layout is described in which multiple light-receiving lenses 111 are arranged in one column along the X direction, and light-receiving element arrays 12 are arranged in two staggered columns. That is, in Figures 10A and 10B, multiple light-receiving element arrays 12 extending along the X direction are staggered on the two readout lines L. Each light-receiving element array 12 has multiple light-receiving elements arranged linearly along its long side direction (X direction). The multiple light-receiving elements constitute multiple light-receiving element arrays 12 extending along the main scanning direction, corresponding to the multiple openings of the aperture member 113. Light passing through each light-receiving lens 111 and through the openings of the aperture member 113 is received by the multiple light-receiving elements of the light-receiving element array 12 corresponding to each light-receiving lens 111. The optical axis of each light-receiving lens 111 is located in the middle of the two readout lines L. That is, the optical axis of each light-receiving lens 111 is located on the center line between the two readout lines L.

[0104] In Figure 10A, the light-receiving element array 12 is positioned opposite to the upper bottom side (short side side) of each trapezoidal light-receiving lens 111. The two ends of each light-receiving element array 12 in the X direction coincide with each other in the Y direction. However, it is not limited to the configuration where the two ends of each light-receiving element array 12 coincide in the Y direction; the light-receiving element arrays 12 can also be arranged in an alternating manner within a range where they do not coincide in the Y direction. Furthermore, each light-receiving lens 111 has a shape in which the width W1 in the Y direction is smaller than the width W2 in the X direction.

[0105] In Figure 10B, light-receiving lenses 111, each having a rectangular convex or concave portion formed at both ends in the X direction, are arranged in a row along the X direction. The light-receiving lenses 111 are arranged such that the convex or concave portions of adjacent light-receiving lenses 111 are combined with each other. Furthermore, each light-receiving lens 111 has a shape where the width W1 in the Y direction is smaller than the width W2 in the X direction.

[0106] 5. Specific examples of stray light The following describes a specific example of stray light incident on the light-receiving element array 12 in a direction inclined towards the X direction relative to the Z direction, using Figures 11A to 11D. Here, the case where light passing through the opening 113E of the aperture member 113 shown in Figure 8B is incident on the light-receiving element array 12 will be described. However, even when using an aperture member 113 with a different configuration than that in Figure 8B, stray light will still be incident on the light-receiving element array 12.

[0107] Figure 11A shows the normal light (not stray light) incident on the aperture component 113 through the light-receiving lens 111 and emitted from the opening 113E being received by the light-receiving element array 12. Figures 11B to 11D show the stray light incident on the aperture component 113 through the light-receiving lens 111 and emitted from the opening 113E being received by the light-receiving element array 12.

[0108] In the example of Figure 11A, the light-receiving lens 1111 located at the end, the aperture component 1131 opposite to the light-receiving lens 1111 in the Z direction, and the light-receiving element array 121 will be described in detail. Light passing through the light-receiving lens 1111 passes through the aperture component 1131 and exits from the opening 113E. At this time, normal light diffuses towards the light-receiving element array 121 at a predetermined field of view and is received only by the light-receiving element array 121. That is, in the other light-receiving element array 12 adjacent to the light-receiving element array 121, normal light emitted from the opening 113E is not received.

[0109] In the example of Figure 11B, the light passing through the light-receiving lens 1111 is reflected by the inner wall of the aperture member 1131 and exits from the opening 113E, thus exiting as stray light at an angle different from the normal light received by the light-receiving element array 121. This stray light is received by the light-receiving element array 122, which is adjacent to the light-receiving element array 121 in the X direction. This stray light intruding into the light-receiving element array 122 becomes noise and therefore needs to be blocked.

[0110] In the example of Figure 11C, light passing through the light-receiving lens 1111 exits through the aperture member 1132 adjacent to the aperture member 1131 in the X direction, and thus exits as stray light at an angle different from the normal light received by the light-receiving element array 122. This stray light is received by the light-receiving element array 123 adjacent to the light-receiving element array 122 in the X direction. This stray light intruding into the light-receiving element array 123 becomes noise and therefore needs to be blocked.

[0111] In the example of Figure 11D, light incident on the light-receiving lens 1111 passes through the adjacent light-receiving lens 1112 in the X direction, is reflected within the light-receiving lens 1112, and exits from the opening 113E through the aperture member 1133 adjacent to the aperture member 1132 opposite to the light-receiving lens 1112 in the X direction. This light exits as stray light at an angle different from the normal light received by the light-receiving element array 123. This stray light is received by the light-receiving element array 124 adjacent to the light-receiving element array 123 in the X direction. This stray light intruding into the light-receiving element array 124 becomes noise and therefore needs to be blocked.

[0112] 6. Examples of light-shielding blocks In this embodiment, in order to block the stray light illustrated in Figures 11B to 11D, in addition to the above-described configuration, a light-shielding block (first light-shielding part) 114 is provided between the aperture member 113 and the light-receiving element array 12. The light-shielding block 114 can be constructed from a component with light-shielding and low reflectivity. At least the surface of the light-shielding block 114 that forms the light path through which light passes is preferably formed from a light-absorbing material.

[0113] Figure 12A is a cross-sectional view of the optical line sensor with light-shielding block 114 installed along the XY plane. Figure 12B is a cross-sectional view of the optical line sensor with light-shielding block 114 installed along the XZ plane. Figure 12C is a cross-sectional view of the optical line sensor with light-shielding block 114 installed along the YZ plane, showing the cross-section at the installation position of the light-receiving lens 1111. Figure 12D is a cross-sectional view of the optical line sensor with light-shielding block 114 installed along the YZ plane, showing the cross-section at the installation position of the light-receiving lens 1112.

[0114] As shown in Figures 12A to 12D, multiple light-shielding blocks 114 are provided corresponding to each aperture component 113 (each opening 113E), and are staggered on the two columns of readout lines L. Specifically, each light-shielding block 114 corresponding to each light-receiving element array 12 is positioned offset in the Y direction relative to each light-receiving element array 12. Thus, as shown in Figure 12A, the staggered arrangement of each light-receiving element array 12 and the staggered arrangement of each light-shielding block 114 are respectively arranged in a line-symmetrical configuration with respect to the center line C between the two columns of readout lines L. That is, the staggered positions of each light-receiving element array 12 relative to the center line C between the two columns of readout lines L are opposite to the staggered positions of each light-shielding block 114.

[0115] As shown in Figure 12B, a light-shielding film 113F is provided between adjacent aperture components 113. Each light-shielding film 113F constitutes a third light-shielding portion covering the gap between adjacent aperture components 113. Each light-shielding film 113F can extend along the Y direction between adjacent aperture components 113 from one holding plate 112A to the other holding plate 112B. Thus, stray light intruding from the gap between adjacent aperture components 113 can be prevented by the light-shielding film 113F, thereby effectively preventing stray light from incident on each light-receiving element array 12. However, the third light-shielding portion is not limited to a film-shaped light-shielding film 113F, as long as it is a component that can cover the gap between adjacent aperture components 113.

[0116] As shown in Figure 12C, the light-receiving element array 121, which faces the light-receiving lens 1111 and the aperture component 1131, is located on one side relative to the center line C between the two columns of readout lines L, while the light-shielding block 1141 is located on the other side relative to the center line C between the two columns of readout lines L. Additionally, as shown in Figure 12D, the light-shielding block 1142, which faces the light-receiving lens 1112 and the aperture component 1132, is located on one side relative to the center line C between the two columns of readout lines L, while the light-receiving element array 122 is located on the other side relative to the center line C between the two columns of readout lines L.

[0117] As shown in Figures 12C and 12D, the light-receiving lens array 11 is held by a pair of sensor supports 115. Specifically, one of the plate-shaped sensor supports 115 abuts against a holding plate 112 of one side of the light-receiving lens array 11, and the other sensor support 115 abuts against the holding plate 112 of the other side of the light-receiving lens array 11. A light-shielding block 1141 is mounted on one sensor support 115, and a light-shielding block 1142 is mounted on the other sensor support 115. Alternatively, the light-shielding blocks 1141 and 1142 may be fixed by abutting against only one side of the sensor support 115.

[0118] In this way, multiple light-shielding blocks 114 located on one side of the center line C between the two columns of reading lines L can be mounted on one side of the sensor bracket 115, and multiple light-shielding blocks 114 located on the other side of the center line C between the two columns of reading lines L can be mounted on the other side of the sensor bracket 115. However, it is not limited to the configuration in which the multiple light-shielding blocks 114 are set separately, but it is also possible to configure the multiple light-shielding blocks 114 as a single light-shielding block (first light-shielding part).

[0119] When viewed from the Z direction, the openings 113E formed in each aperture component 113 are located between the two rows of reading lines L. More specifically, the openings 113E formed in each aperture component 113 are arranged in a linear configuration along the center line C between the two rows of reading lines L.

[0120] 7. An embodiment of a pair of retaining plates and a pair of sensor holders In the examples shown in Figures 12A to 12D, multiple light-receiving lens arrays 11 are clamped by a pair of sensor supports 115. That is, instead of clamping only one light-receiving lens array 11, multiple light-receiving lens arrays 11 arranged in the X direction are clamped in the Y direction between the pair of sensor supports 115. Furthermore, in Figure 12A, only one light-receiving lens array 11 and a portion of another light-receiving lens array 11 adjacent to it are illustrated, but it is also possible for three or more light-receiving lens arrays 11 to be clamped by a pair of sensor supports 115.

[0121] In each of the light-receiving lens arrays 11, at least two light-receiving lenses 111 and at least one aperture component 113 are held in the Y direction between a pair of holding plates 112. In the examples of Figures 12A to 12D, three light-receiving lenses 111 and three aperture components 113 are mounted on one holding plate 112, and three light-receiving lenses 111 and three aperture components 113 are also mounted on the other holding plate 112, thereby holding six light-receiving lenses 111 and six aperture components 113 between a pair of holding plates 112.

[0122] However, the number of light-receiving lenses 111 clamped between the pair of retaining plates 112 is not limited to six; it can be two to five, or even seven or more. Similarly, the number of aperture members 113 clamped between the pair of retaining plates 112 is not limited to six; it can be two to five, or even seven or more. Furthermore, if the configuration is not such that the aperture member 113 is provided separately for each of the plurality of openings 113E, but rather that a plurality of openings 113E are formed in one aperture member 113, then the aperture member 113 clamped between the pair of retaining plates 112 can be one.

[0123] In this way, by using a pair of retaining plates 112, at least two light-receiving lenses 111 sandwiched between the pair of retaining plates 112, and at least one aperture component 113 as a light-receiving lens array 11, and using a pair of sensor brackets 115 to hold multiple light-receiving lens arrays 11 in the Y direction, even if a portion of the light-receiving lenses 111 contained in any one of the light-receiving lens arrays 11 is defective, only that light-receiving lens array 11 needs to be replaced, thus minimizing the waste of components.

[0124] Furthermore, the pair of retaining plates 112 may have a fitting portion (not shown) for interlocking and connecting the pair of retaining plates 112 together. As the fitting portion, any configuration can be adopted, such as a snap-fit ​​structure having a claw portion that engages with a bearing portion, or a press-fit structure having a shaft portion that engages with a hole, etc.

[0125] As shown in Figures 12C and 12D, each of a pair of sensor holders 115 is formed in an L-shape having a first plate portion 1151 and a second plate portion 1152. The first plate portion 1151 is opposite to a plurality of light-receiving lens arrays 11, and the second plate portion 1152 extends from one end of the first plate portion 1151 toward a side opposite to the side of the plurality of light-receiving lens arrays 11. The second plate portion 1152 is formed to protrude in the Y direction from the end of the first plate portion 1151 on the side opposite to the light incident side.

[0126] However, the following configuration may also be adopted: the second plate portion 1152 extends not only from one end of the first plate portion 1151 toward the side opposite to the side of the plurality of light-receiving lens array 11, but also toward the side of the plurality of light-receiving lens array 11. In this case, the amount of the second plate portion 1152 protruding toward the side of the plurality of light-receiving lens array 11 is less than the amount of the second plate portion 1152 protruding toward the side opposite to the Y direction, which is included in the concept of "L-shape".

[0127] A light-receiving element array 12 is mounted on a light-receiving substrate 12B having circuitry. Signals output from the plurality of light-receiving elements included in the light-receiving element array 12 are processed in the circuitry of the light-receiving substrate 12B on which these light-receiving elements are mounted. The number of light-receiving substrates 12B is not limited; one light-receiving substrate 12B can be provided for a pair of sensor supports 115, or one light-receiving substrate 12B can be provided for a pair of holding plates 112.

[0128] The light-receiving substrate 12B is mounted across a pair of sensor supports 115 on the second plate portion 1152 side. That is, on the side of the pair of sensor supports 115 opposite to the light incident side, one end of the light-receiving substrate 12B in the Y direction is mounted to one sensor support 115, and the other end is mounted to the other sensor support 115. Therefore, based on positioning a plurality of light-receiving lenses 111 and a plurality of aperture components 113 between the first plate portions 1151 of the pair of sensor supports 115, the light-receiving substrate 12B can be mounted across a pair of sensor supports 115 on the second plate portion 1152 side. Thus, the plurality of light-receiving lenses 111 and the plurality of aperture components 113 can be accurately positioned relative to the plurality of light-receiving elements mounted on the light-receiving substrate 12B.

[0129] Each light-receiving lens array 11 is provided with a cover member 11A to prevent foreign matter from entering from the incident side of light. The cover member 11A is arranged such that it spans the end faces of the light-incident sides of a pair of retaining plates 112. That is, on the light-incident side of the pair of retaining plates 112, one end of the cover member 11A in the Y direction is mounted to the end face of one retaining plate 112 (retaining plate 112A), and the other end is mounted to the end face of the other retaining plate 112 (retaining plate 112B).

[0130] The cover component 11A is preferably formed of a transparent component, such as a transparent film, so as not to obstruct light from entering the light-receiving lens 111. The cover component 11A is not limited to a configuration provided for each light-receiving lens array 11, but can also be a shared cover component 11A provided for multiple light-receiving lens arrays 11. In this case, it can be a configuration in which one cover component 11A is provided for a pair of sensor supports 115.

[0131] Figure 13A is a view of one of the holding plates 112A as seen along the Y direction from the side of the light-receiving lens 111. Figure 13B is a view of the other holding plate 112B as seen along the Y direction from the side opposite to the light-receiving lens 111. Each holding plate 112A, 112B is a rectangular plate with a long strip shape along the X direction; in this example, the lengths in the X and Y directions are the same.

[0132] Multiple positioning holes 1121 are formed in each retaining plate 112A, 112B. Each positioning hole 1121 is a through hole formed through a cylindrical inner surface composed of a smooth surface. In this example, positioning holes 1121 are formed at both ends in the X direction of each retaining plate 112A, 112B. However, more than three positioning holes 1121 may also be formed.

[0133] Furthermore, multiple threaded holes 1122 for fixing are formed in each retaining plate 112A, 112B. Each threaded hole 1122 is a through hole with a threaded groove formed on the inner surface of a cylindrical shape. In this example, the threaded holes 1122 for fixing are formed at both ends in the X direction of each retaining plate 112A, 112B and near the positioning hole 1121. However, more than three threaded holes 1122 for fixing may also be formed.

[0134] Figure 14A is a cross-sectional view of the optical line sensor along the YZ plane, showing the cross-section obtained by cutting at the location of the positioning hole 1121. In Figure 14A, the light-shielding block 114 is omitted. As shown in Figure 14A, positioning pins 1153 are formed on a pair of sensor supports 115 at positions corresponding to the positioning holes 1121 formed in a pair of retaining plates 112. Therefore, by inserting each positioning pin 1153 into each positioning hole 1121, the pair of retaining plates 112 can be positioned on the pair of sensor supports 115.

[0135] Each positioning pin 1153 is an example of a positioning member used to position a pair of retaining plates 112 onto a pair of sensor supports 115. Specifically, one of the pair of retaining plates 112 (retaining plate 112A) is positioned onto one of the pair of sensor supports 115 (sensor support 115A) by the positioning pin 1153, which serves as a first positioning member. Additionally, the other of the pair of retaining plates 112 (retaining plate 112B) is positioned onto the other of the pair of sensor supports 115 (sensor support 115B) by the positioning pin 1153, which serves as a second positioning member.

[0136] As described above, after the retaining plates 112A and 112B are positioned on the sensor supports 115A and 115B, the sensor supports 115A and 115B are connected to each other, as shown in FIG. 14A, thereby positioning the retaining plates 112A and 112B in an opposing state in the Y direction. Positioning is achieved using the positioning pins 1153, facilitating assembly and enabling accurate positioning and fixation of each light-receiving lens array 11 between a pair of sensor supports 115. This allows for easy and accurate positioning of the plurality of light-receiving lenses 111 and the plurality of aperture components 113.

[0137] However, the first positioning component and the second positioning component are not limited to the positioning pins 1153 formed on the pair of sensor supports 115. For example, the positioning pins may be formed on the pair of retaining plates 112, which are inserted into the positioning holes formed on the pair of sensor supports 115. Alternatively, the pair of retaining plates 112 may be positioned on the pair of sensor supports 115 by components other than the positioning pins.

[0138] Figure 14B is a cross-sectional view of the optical line sensor along the YZ plane, showing the cross-section obtained by cutting at the location of the fixing threaded hole 1122. In Figure 14B, the light-shielding block 114 is omitted. As shown in Figure 14B, through holes 1154 are formed in a pair of sensor supports 115 at positions corresponding to the fixing threaded holes 1122 formed in a pair of retaining plates 112. The inner diameter of each through hole 1154 is larger than the inner diameter of the fixing threaded hole 1122. A fixing screw 1155 is inserted into each through hole 1154 from the side opposite to the fixing threaded hole 1122, and the tip of the fixing screw 1155, after passing through each through hole 1154, is screwed into the fixing threaded hole 1122.

[0139] Each fixing screw 1155 is a component used to fix a pair of retaining plates 112 to a pair of sensor brackets 115. Specifically, a fixing screw 1155, which is inserted through a through hole 1154 formed in one of the pair of sensor brackets 115 (sensor bracket 115A), is screwed into a fixing threaded hole 1122 formed in one of the pair of retaining plates 112 (retaining plate 112A), thereby fixing one of the pair of retaining plates 112 (retaining plate 112A) to one of the pair of sensor brackets 115 (sensor bracket 115A). Additionally, a fixing screw 1155, which is inserted into a through hole 1154 formed in the other side of a pair of sensor brackets 115 (sensor bracket 115B), is screwed into a fixing threaded hole 1122 formed in the other side of a pair of retaining plates 112 (retaining plate 112B), thereby fixing the other side of a pair of retaining plates 112 (retaining plate 112B) to the other side of a pair of sensor brackets 115 (sensor bracket 115B).

[0140] Next, referring again to Figures 13A and 13B, the fixing and adjustment methods of the light-receiving lens 111 will be described. Each light-receiving lens 111 is fixed to each retaining plate 112A, 112B using adhesive. Multiple injection holes 1123 for injecting adhesive are formed in each retaining plate 112A, 112B. At the position opposite to each light-receiving lens 111 on the retaining plates 112A, 112B where the light-receiving lenses 111 are mounted, at least one injection hole 1123 is formed for each light-receiving lens 111.

[0141] In the examples of Figures 13A and 13B, four injection holes 1123 are formed for each light-receiving lens 111 at positions opposite to the light-receiving lenses 111 on the holding plates 112A and 112B where the light-receiving lenses 111 are mounted. Specifically, two injection holes 1123 are formed at positions opposite to the two ends of each light-receiving lens 111 in the X direction, symmetrically arranged with respect to the center of each light-receiving lens 111 in the X direction. The four injection holes 1123 are arranged in the X direction. However, the injection holes 1123 may be configured to have only one for each light-receiving lens 111, or they may be configured to have two, three, or more than five.

[0142] Adhesive is injected into each injection hole 1123 formed in each of the retaining plates 112A and 112B. The adhesive injected into each injection hole 1123 cures while a portion of it is in contact with each light-receiving lens 111. The retaining plates 112A and 112B are fixed to each light-receiving lens 111 by the adhesive force of the adhesive. The material of the adhesive is not particularly limited; for example, an adhesive mainly composed of synthetic resins such as epoxy resin can be used.

[0143] At the positions opposite to each light-receiving lens 111 on the retaining plates 112A and 112B, where the light-receiving lenses 111 are mounted, at least one first adjustment threaded hole 1124 is formed in addition to the aforementioned injection hole 1123. In the examples of Figures 13A and 13B, two first adjustment threaded holes 1124 are formed for each light-receiving lens 111. Specifically, one first adjustment threaded hole 1124 is formed at each position opposite to both ends of each light-receiving lens 111 in the Z direction. The two first adjustment threaded holes 1124 are formed in an arrangement in the Z direction. However, the first adjustment threaded hole 1124 may be configured to have only one for each light-receiving lens 111, or it may be configured to have three or more.

[0144] The first adjusting screw 1125 is screwed into the first adjusting threaded hole 1124 from the side of each retaining plate 112A, 112B opposite to the side of each light-receiving lens 111 (back side of the paper in Figure 13A, front side of the paper in Figure 13B). The front end of each first adjusting screw 1125 abuts against each light-receiving lens 111, but is not screwed into each light-receiving lens 111. Therefore, by adjusting the amount of protrusion of each first adjusting screw 1125 from each retaining plate 112A, 112B, the front end of each first adjusting screw 1125 can be used to press each light-receiving lens 111, and the angle of each light-receiving lens 111 relative to each retaining plate 112A, 112B can be adjusted.

[0145] If multiple first adjusting screws 1125 are provided for a light-receiving lens 111, the angle of each light-receiving lens 111 can be finely adjusted by each first adjusting screw 1125. For example, as in the examples of FIG13A and FIG13B, if two first adjusting screws 1125 are provided for a light-receiving lens 111 in a manner arranged in the Z direction, the angle of each light-receiving lens 111 in the Y direction relative to the Z direction can be finely adjusted by adjusting the amount of protrusion of each first adjusting screw 1125 relative to each retaining plate 112A, 112B.

[0146] Figure 15 is a cross-sectional view of the optical line sensor along the YZ plane, showing a cross-section of one end of a pair of sensor supports 115 in the X direction. As shown in Figure 15, a spacer 116 is provided at one end of the pair of sensor supports 115 in the X direction. The spacer 116 is a component whose two end faces in the Y direction extend parallel to the X and Z directions, and the width of the spacer 116 in the Y direction is consistent with the width of the light-receiving lens array 11 in the Y direction.

[0147] One end face of the spacer 116 in the Y direction abuts against the first plate portion 1151 of one sensor bracket 115A, and the other end face of the spacer 116 in the Y direction abuts against the first plate portion 1151 of the other sensor bracket 115B. A through hole 1156 extending in the Y direction is formed in the first plate portion 1151 of each sensor bracket 115A and 115B at a position opposite to the spacer 116 in the Y direction. In the example of FIG. 15, two through holes 1156 are formed at one end of each sensor bracket 115A and 115B in the X direction. The two through holes 1156 are formed at both ends of the first plate portion 1151 of each sensor bracket 115A and 115B in the Z direction.

[0148] Furthermore, a fixing threaded hole 1161 is formed in the spacer 116 at a position opposite to each through hole 1156. A fixing screw 1157 is inserted from the side opposite to the spacer 116 through hole 1156 in each sensor bracket 115A, 115B, with the tip of the screw 1157 screwed into the fixing threaded hole 1161 of the spacer 116 opposite to each through hole 1156. Thus, the spacer 116 is positioned between a pair of sensor brackets 115, fixing a plurality of light-receiving lens arrays 11 in the Y direction using the pair of sensor brackets 115. In this state, the distance between the pair of sensor brackets 115 remains constant through the spacer 116, thereby enabling more accurate positioning of the plurality of light-receiving lenses 111 and the plurality of aperture components 113.

[0149] In Figure 15, only the structure of one end of a pair of sensor supports 115 in the X direction is described, but the other end in the X direction has the same structure, with a spacer 116 provided between the pair of sensor supports 115. However, the number of fixing screws 1157 connecting each sensor support 115A, 115B to the spacer 116 is not limited to the number of fixing screws 1157 shown in Figure 15. In addition, each sensor support 115A, 115B and the spacer 116 can also be connected by fixing components other than fixing screws 1157.

[0150] As shown in Figure 15, at least one second adjustment threaded hole 1158 is formed on the first plate portion 1151 of each sensor bracket 115A, 115B, opposite to a pair of holding plates 112 of each light-receiving lens array 11. In the example of Figure 15, two second adjustment threaded holes 1158 are formed opposite to one holding plate 112A of each light-receiving lens array 11, and two second adjustment threaded holes 1158 are formed opposite to the other holding plate 112B of each light-receiving lens array 11.

[0151] Two second adjustment threaded holes 1158, opposite to the retaining plate 112A of one of the light-receiving lens arrays 11, are positioned opposite the two ends of the retaining plate 112A in the Z direction and are arranged in the Z direction. Similarly, two second adjustment threaded holes 1158, opposite to the retaining plate 112B of the other of the light-receiving lens arrays 11, are positioned opposite the two ends of the retaining plate 112B in the Z direction and are arranged in the Z direction. However, the second adjustment threaded holes 1158 may be configured to have only one for each retaining plate 112, or they may be configured to have three or more.

[0152] The second adjusting screws 1159 are screwed into the second adjusting threaded holes 1158 from the side of the first plate portion 1151 of each sensor bracket 115A, 115B opposite to the side of the light-receiving lens array 11. The front end of each second adjusting screw 1159 abuts against each retaining plate 112A, 112B, but is not screwed into each retaining plate 112A, 112B. Therefore, by adjusting the amount of protrusion of each second adjusting screw 1159 from the first plate portion 1151 of each sensor bracket 115A, 115B, the angle of each retaining plate 112A, 112B relative to each sensor bracket 115A, 115B can be adjusted by pressing each retaining plate 112A, 112B with the front end of each second adjusting screw 1159.

[0153] If multiple second adjusting screws 1159 are provided for a retaining plate 112, the angles of each retaining plate 112A, 112B can be finely adjusted using each second adjusting screw 1159. For example, as in the example of FIG. 15, if two second adjusting screws 1159 are arranged in the Z direction for a retaining plate 112, the angle of each retaining plate 112A, 112B in the Y direction relative to the Z direction can be finely adjusted by adjusting the amount of protrusion of each second adjusting screw 1159 relative to the first plate portion 1151 of each sensor bracket 115A, 115B. Thus, even after each light-receiving lens array 11 is fixed between a pair of sensor brackets 115, the optical axis of the light-receiving lens 111 can be easily and accurately adjusted.

[0154] 8. Elongation of optical line sensors Figure 16 is a schematic top view illustrating an example of an elongated optical line sensor. In this example, multiple pairs of sensor supports 115 are arranged in the X direction. That is, multiple pairs of sensor supports 115, which sandwich multiple light-receiving lens arrays 11 in the Y direction, are arranged in a straight line along the X direction. This expands the reading range in the X direction.

[0155] In the example of Figure 16, spacers 116 are provided at both ends of each sensor bracket 115 in the X direction. However, this configuration is not limited to this one; it is also possible to omit the spacers 116 between adjacent sensor brackets 115 in the X direction, thus eliminating the spacers 116 between adjacent light-receiving lens arrays 11. In this case, components other than the spacers 116 can be used to connect adjacent sensor brackets 115 in the X direction.

[0156] 9. Specific examples of preventing stray light intrusion The following describes a specific example of preventing stray light from entering outside the light-receiving element array 121 by means of the light-shielding block 114. Here, the case of preventing stray light corresponding to FIG11B to FIG11D from entering outside the light-receiving element array 121 will be described, but in other aspects, stray light toward the light-receiving element array 121 can also be blocked by the light-shielding block 114.

[0157] Figure 17A is a diagram showing the situation corresponding to Figure 11B where stray light is prevented from entering the light-receiving element array 122. Figure 17B is a cross-sectional view along the YZ plane at the location of the light-receiving lens 1111 in Figure 17A, showing the situation where stray light toward the light-receiving element array 122 is blocked by the light-shielding block 1141. Figure 17C is a cross-sectional view along the YZ plane at the location of the light-receiving lens 1111 in Figure 17A, showing the situation where normal light is incident on the light-receiving element array 121.

[0158] As shown in Figures 17A and 17B, light passing through the light-receiving lens 1111 is reflected by the inner wall of the aperture component 1131 and exits from the opening 113E. Thus, stray light traveling towards the light-receiving element array 122 travels in a direction inclined relative to the Z direction towards the X and Y directions. At this time, since the light-shielding block 1141 is located on the straight line connecting the opening 113E of the aperture component 1131 and the light-receiving element array 122, the stray light is blocked by the light-shielding block 1141.

[0159] In this way, light passing through the opening 113E of the aperture member 1131 adjacent to the opening 113E of the aperture member 1132 corresponding to the light-receiving element array 122 is blocked by the light-shielding block 1141, which is provided corresponding to the opening 113E of the adjacent aperture member 1131. As a result, light passing through the opening 113E of the adjacent aperture member 1131 is prevented from entering the light-receiving element array 122.

[0160] On the other hand, as shown in FIG17C, normal light incident on the aperture component 1131 through the light-receiving lens 1111 and emitted from the opening 113E travels in a direction inclined towards the Y direction relative to the Z direction. At this time, since the light-shielding block 1141 is disposed at a position offset in the Y direction relative to the light-receiving element array 121, the normal light is received by the light-receiving element array 121 and is not blocked by the light-shielding block 1141.

[0161] Figure 18A is a diagram showing the situation corresponding to Figure 11C where stray light is prevented from entering the light-receiving element array 123. Figure 18B is a cross-sectional view along the YZ plane at the location of the light-receiving lens 1112 in Figure 18A, showing the situation where stray light toward the light-receiving element array 123 is blocked by the light-shielding block 1142. Figure 18C is a cross-sectional view along the YZ plane at the location of the light-receiving lens 1112 in Figure 18A, showing the situation where normal light is incident on the light-receiving element array 122.

[0162] As shown in Figures 18A and 18B, light passing through the light-receiving lens 1111 passes through the aperture member 1132 adjacent to the aperture member 1131 in the X direction and exits from the opening 113E, thus traveling as stray light toward the light-receiving element array 123 in a direction inclined relative to the Z direction towards the X and Y directions. At this time, since the light-shielding block 1142 is located on the straight line connecting the opening 113E of the aperture member 1132 and the light-receiving element array 123, the stray light is blocked by the light-shielding block 1142.

[0163] In this way, light passing through the opening 113E of the aperture member 1132 adjacent to the opening 113E of the aperture member 1133 corresponding to the light-receiving element array 123 is blocked by the light-shielding block 1142, which is provided corresponding to the opening 113E of the adjacent aperture member 1132. As a result, light passing through the opening 113E of the adjacent aperture member 1132 is prevented from entering the light-receiving element array 123.

[0164] On the other hand, as shown in FIG18C, normal light incident on the aperture component 1132 through the light-receiving lens 1112 and emitted from the opening 113E travels in a direction inclined towards the Y direction relative to the Z direction. At this time, since the light-shielding block 1142 is disposed at a position offset in the Y direction relative to the light-receiving element array 122, the normal light is received by the light-receiving element array 122 and is not blocked by the light-shielding block 1142.

[0165] Figure 19A is a diagram showing the situation corresponding to Figure 11D where stray light is prevented from entering the light-receiving element array 124. Figure 19B is a cross-sectional view along the YZ plane at the location of the light-receiving lens 1113 in Figure 19A, showing the situation where stray light toward the light-receiving element array 124 is blocked by the light-shielding block 1143. Figure 19C is a cross-sectional view along the YZ plane at the location of the light-receiving lens 1113 in Figure 19A, showing the situation where normal light is incident on the light-receiving element array 123.

[0166] As shown in Figures 19A and 19B, light incident on the light-receiving lens 1111 passes through the light-receiving lens 1112 adjacent to it in the X direction. After being reflected within the light-receiving lens 1112, it passes through the aperture member 1133 adjacent to the light-receiving lens 1112 in the X direction and exits from the opening 113E. Thus, stray light traveling toward the light-receiving element array 124 travels in a direction inclined relative to the Z direction towards the X and Y directions. At this time, since the light-shielding block 1143 is located on the straight line connecting the opening 113E of the aperture member 1133 and the light-receiving element array 124, the stray light is blocked by the light-shielding block 1143.

[0167] In this way, light passing through the opening 113E of the aperture member 1133 adjacent to the opening 113E of the aperture member 1134 corresponding to the light-receiving element array 124 is blocked by the light-shielding block 1143, which is provided corresponding to the opening 113E of the adjacent aperture member 1133. As a result, light passing through the opening 113E of the adjacent aperture member 1133 is prevented from entering the light-receiving element array 124.

[0168] On the other hand, as shown in FIG19C, normal light incident on the aperture component 1133 through the light-receiving lens 1113 and emitted from the opening 113E travels in a direction inclined towards the Y direction relative to the Z direction. At this time, since the light-shielding block 1143 is disposed at a position offset in the Y direction relative to the light-receiving element array 123, the normal light is received by the light-receiving element array 123 and is not blocked by the light-shielding block 1143.

[0169] 10. Examples of variations of light-blocking blocks Figure 20A is a diagram illustrating a modified example of the light-shielding block 114. Figure 20B is a cross-sectional view along the YZ plane at the location of the light-receiving lens 1111 in Figure 20A, showing normal light incident on the light-receiving element array 121. Figure 20C is a cross-sectional view along the YZ plane at the location of the light-receiving lens 1112 adjacent to the light-receiving lens 1111 in Figure 20A, showing normal light incident on the light-receiving element array 122.

[0170] As shown in Figure 20A, the width of the light-shielding block 114 in the X direction is less than or equal to the width W3 of the light-receiving element array 12. Furthermore, the width of the light-shielding block 114 in the Z direction is less than or equal to the distance D between the aperture member 113 and the light-receiving element array 12, which are opposite each other in the Z direction. Preferably, the light-shielding block 114 does not contact the aperture member 113 or the light-receiving element array 12.

[0171] A through-hole 114A is formed in the light-shielding block 114. The through-hole 114A extends the optical path of light entering the light-receiving element array 12 corresponding to the opening 113E of the aperture member 113. As shown in FIG20B, normal light passing through the opening 113E of the aperture member 1131 enters the light-receiving element array 121 through the through-hole 114A formed in the light-shielding block 1141. At this time, stray light emitted from the opening 113E of the aperture member 1131 is emitted in a direction different from the direction of extension of the through-hole 114A, and therefore hits the light-shielding block 1141 (the inner peripheral surface of the through-hole 114A) and is absorbed.

[0172] Furthermore, as shown in Figure 20C, normal light passing through the opening 113E of the aperture component 1132 enters the light-receiving element array 122 through the through-hole 114A formed in the light-shielding block 1142. At this time, stray light emitted from the opening 113E of the aperture component 1132 is emitted in a direction different from the direction in which the through-hole 114A extends, and therefore hits the light-shielding block 1142 (the inner peripheral surface of the through-hole 114A) and is absorbed.

[0173] Thus, each through hole 114A is formed into a cone shape that is inclined towards the Y direction relative to the Z direction. Furthermore, in Figures 20B and 20C, only the configuration of light-shielding blocks 1141 and 1142 is described, but for the other light-shielding blocks 114, it is sufficient to alternately arrange light-shielding blocks 114 with the same configuration as in Figure 20B and light-shielding blocks 114 with the same configuration as in Figure 20C along the X direction.

[0174] Figures 20D and 20E are diagrams illustrating a modified example of the through-hole 114A of the light-shielding block 114 shown in Figures 20B and 20C. In this example, the through-hole 114B formed in each light-shielding block 114 extends in a stepped manner along the direction of inclination of the through-hole 114B (the direction in which the through-hole 114B extends). That is, each through-hole 114B alternately has a portion extending in the Z direction (vertical portion) and a portion extending in the X direction (horizontal portion), and the connection between the vertical portion and the horizontal portion forms a stepped surface.

[0175] As shown in Figure 20D, normal light passing through the opening 113E of the aperture component 1131 enters the light-receiving element array 121 through the through hole 114B formed in the light-shielding block 1141. At this time, stray light emitted from the opening 113E of the aperture component 1131 is emitted in a direction different from the direction in which the through hole 114B extends, and therefore hits the light-shielding block 1141 (the inner peripheral surface of the through hole 114B) and is absorbed.

[0176] Furthermore, as shown in Figure 20E, normal light passing through the opening 113E of the aperture component 1132 enters the light-receiving element array 122 through the through-hole 114B formed in the light-shielding block 1142. At this time, stray light emitted from the opening 113E of the aperture component 1132 is emitted in a direction different from the direction in which the through-hole 114B extends, and therefore encounters the light-shielding block 1142 (the inner peripheral surface of the through-hole 114B) and is absorbed.

[0177] Furthermore, in Figures 20D and 20E, only the configuration of light-shielding blocks 1141 and 1142 is described. However, for the other light-shielding blocks 114, light-shielding blocks 114 with the same configuration as in Figure 20D and light-shielding blocks 114 with the same configuration as in Figure 20E can be alternately arranged along the X direction.

[0178] Figure 21A is a diagram illustrating another variation of the light-shielding block 114. Figure 21B is a cross-sectional view along the YZ plane at the location of the light-receiving lens 1111 in Figure 21A, showing normal light incident on the light-receiving element array 121. Figure 21C is a cross-sectional view along the YZ plane at the location of the light-receiving lens 1112 adjacent to the light-receiving lens 1111 in Figure 21A, showing normal light incident on the light-receiving element array 122.

[0179] As shown in Figure 21A, the width of the light-shielding block 114 in the X direction is greater than or equal to the field of view W4 at the location of the light-shielding block 114 corresponding to the opening 113E of the aperture member 113. Preferably, the width of the light-shielding block 114 in the X direction is greater than or equal to the field of view W4 at the location of the light-shielding block 114 corresponding to the opening 113E of the aperture member 113 (see Figure 21A), and less than or equal to the width W3 of the light-receiving element array 12 (see Figure 20A).

[0180] As shown in Figure 21B, normal light passing through the opening 113E of the aperture component 1131 is received by the light-receiving element array 121 without being blocked by the light-blocking block 1141. Additionally, as shown in Figure 21C, normal light passing through the opening 113E of the aperture component 1132 is received by the light-receiving element array 122 without being blocked by the light-blocking block 1142.

[0181] Furthermore, in Figures 21B and 21C, only the configuration of light-shielding blocks 1141 and 1142 is described. However, for other light-shielding blocks 114, light-shielding blocks 114 with the same configuration as in Figure 21B and light-shielding blocks 114 with the same configuration as in Figure 21C can be alternately arranged along the X direction.

[0182] 10: Light Source Section 11: Light-receiving lens array 11A: Cover component 12: Light-receiving element array 12A: Light-receiving surface 12B:Light-receiving substrate 13:Substrate 14: Protective Glass 15: Ultraviolet light blocking filter 16: Shell 18: Color Filter 20: Focal plane 101: Light guide 102: Cover component 103: Light source 111, 1111, 1112, 1113: Light-receiving lenses 111A: First page 111B: Second page 111C: Inclined surface 112, 112A, 112B: Retention Plate 1121: Positioning hole 1122: Threaded hole for fixing 1123: Injection Hole 1124: First adjustment threaded hole 1125: First adjusting screw 113, 1131, 1132, 1133, 1134: Aperture components 113A, 113D, 113E: Opening 113B: Light-blocking wall 113C: concave part 113F: Light-blocking film 114, 1141, 1142, 1143: Light-blocking blocks 114A, 114B: Through holes 115, 115A, 115B: Sensor bracket 1151: First section 1152: Second section 1153: Positioning pin 1154, 1156: Through holes 1155, 1157: Fixing screws 1158: Second adjustment threaded hole 1159: Second Adjusting Screw 116: Spacer 1161: Threaded hole for fixing 120: Light-receiving lens 121, 122, 123, 124: Light-receiving element array 130: Light-receiving lens 200: Installation stand 201: First Positioning Department 202: Pressing mechanism 203: Second Positioning Unit 300: Optical axis alignment fixture 301: First through hole 302: Second through hole 303: Third through hole C: Centerline D: Distance L: Read line P: Light diffusion pattern W1, W2, W3, W4: Width X, Y, Z: Direction

Claims

1. An optical line sensor, said optical line sensor using a readout line extending in a main scanning direction to read an object moving relatively along a sub-scanning direction, wherein, The optical line sensor includes: a plurality of light-receiving lenses arranged in a linear shape along the main scanning direction to allow light from an illuminated object to pass through; an aperture member having a plurality of openings through which light passing through the plurality of light-receiving lenses passes; and a plurality of light-receiving elements arranged in a linear shape along the main scanning direction to receive light passing through the plurality of openings. The plurality of light-receiving elements constitute a plurality of light-receiving element arrays extending along the main scanning direction corresponding to the plurality of openings. The plurality of light-receiving element arrays are staggered on two columns of the readout lines. A first light-shielding portion is provided between the aperture member and the plurality of light-receiving element arrays to prevent light passing through an opening adjacent to the opening corresponding to each light-receiving element array from entering each light-receiving element array.

2. The optical line sensor as claimed in claim 1, wherein, The first light-shielding part is provided in multiple ways corresponding to the plurality of openings. Light passing through the opening adjacent to the opening corresponding to each light-receiving element array is blocked by the first light-shielding part provided in the corresponding way to the adjacent opening.

3. The optical line sensor as claimed in claim 2, wherein, Multiple first light-shielding portions are staggered on the two columns of the reading lines.

4. The optical line sensor as claimed in claim 2, wherein, The width of the main scanning direction of the first light-shielding part is greater than the field width of the adjacent opening corresponding to the first light-shielding part at the setting position of the first light-shielding part, and less than the width of the light-receiving element array.

5. The optical line sensor as claimed in claim 1, wherein, A through hole is formed in the first light-shielding part, and the through hole extends along the light path of light that enters the light-receiving element array corresponding to the opening through the opening.

6. The optical line sensor as claimed in claim 5, wherein, When viewed from a direction orthogonal to the main scanning direction and the sub-scanning direction, the plurality of openings are located between the two columns of readout lines, and the through hole is formed as a cone shape that is inclined toward the sub-scanning direction relative to the direction orthogonal to the main scanning direction and the sub-scanning direction.

7. The optical line sensor as claimed in claim 6, wherein, The through hole extends in a stepped manner along the inclined direction of the through hole.

8. The optical line sensor as claimed in claim 1, wherein, The plurality of light-receiving lenses respectively constitute a telecentric optical system, and the width of the sub-scanning direction of each light-receiving lens is smaller than the width of the main scanning direction.

9. The optical line sensor as claimed in claim 1, wherein, The plurality of openings are formed in the shape of a frustum.

10. The optical line sensor as claimed in claim 1, wherein, The aperture component is provided with a plurality of pinholes that are spaced apart from each opening and are provided for light to enter after passing through the plurality of openings.

11. The optical line sensor as claimed in claim 9 or 10, wherein, A second light-shielding portion is formed in the aperture component, which blocks a portion of the opening to prevent stray light from entering.

12. The optical line sensor as claimed in claim 1, wherein, The aperture component is composed of a plurality of aperture components respectively having the openings formed thereon, and the optical line sensor further comprises: a pair of holding plates that hold at least two of the plurality of light-receiving lenses and at least one of the plurality of aperture components in the sub-scanning direction; The system includes a pair of sensor supports, with the pair of retaining plates, the at least two light-receiving lenses clamped between the pair of retaining plates, and the at least one aperture component forming a light-receiving lens array. Multiple light-receiving lens arrays arranged in the main scanning direction are clamped in the sub-scanning direction. One side of the pair of retaining plates is positioned on one side of the pair of sensor supports by a first positioning component, and the other side of the pair of retaining plates is positioned on the other side of the pair of sensor supports by a second positioning component. The pair of sensor supports are interconnected, thereby positioning the pair of retaining plates in an opposing state in the sub-scanning direction.

13. The optical line sensor as claimed in claim 12, wherein, Each of the pair of retaining plates has a threaded hole for fixing. Each of the pair of sensor brackets has a through hole at a position opposite to the threaded hole for fixing. A first fixing screw, which passes through the through hole formed on one side of the pair of sensor brackets, is screwed into the threaded hole for fixing on one side of the pair of retaining plates, thereby fixing one side of the pair of retaining plates to one side of the pair of sensor brackets. A second fixing screw, which passes through the through hole formed on the other side of the pair of sensor brackets, is screwed into the threaded hole for fixing on the other side of the pair of retaining plates, thereby fixing the other side of the pair of retaining plates to the other side of the pair of sensor brackets.

14. The optical line sensor as claimed in claim 12, wherein, The optical line sensor also includes a spacer disposed between the pair of sensor supports to maintain a constant distance between the pair of sensor supports when the plurality of light-receiving lens arrays are clamped in the sub-scanning direction using the pair of sensor supports.

15. The optical line sensor as claimed in claim 12, wherein, The optical line sensor also includes a light-receiving substrate on which the plurality of light-receiving elements are mounted. Each of the pair of sensor brackets is formed in an L-shape having a first plate portion and a second plate portion. The first plate portion is opposite to the plurality of light-receiving lens arrays. The second plate portion extends from one end of the first plate portion to a side opposite to the plurality of light-receiving lens arrays. The light-receiving substrate is mounted such that it spans the pair of sensor brackets on the side of the second plate portion.

16. The optical line sensor as claimed in claim 12, wherein, The optical axes of the plurality of light-receiving lenses are located on the center line between the two columns of reading lines.

17. The optical line sensor as claimed in claim 12, wherein, The pair of sensor holders are arranged in multiple configurations along the main scanning direction.

18. The optical line sensor as claimed in claim 12, wherein, The optical line sensor also includes a third light-shielding portion that covers the gap between adjacent aperture components.

19. The optical line sensor as claimed in claim 12, wherein, The optical line sensor also includes a cover component arranged such that the end faces of the light incident sides of the pair of retaining plates are positioned relative to each other.

20. The optical line sensor as claimed in claim 12, wherein, At least one injection hole is formed in the pair of retaining plates at a position opposite to the light-receiving lens, and the pair of retaining plates and the at least two light-receiving lenses are fixed by adhesive injected into the at least one injection hole.

21. The optical line sensor as claimed in claim 12, wherein, At least one first adjustment threaded hole is formed in the pair of retaining plates at a position opposite to the light-receiving lens. The angle of the light-receiving lens relative to the pair of retaining plates can be adjusted by a first adjustment screw that is screwed into the at least one first adjustment threaded hole and whose front end abuts against the light-receiving lens.

22. The optical line sensor as claimed in claim 12, wherein, In the pair of sensor brackets, at least one second adjustment threaded hole is formed at a position opposite to the retaining plate. The angle of the retaining plate relative to the pair of sensor brackets can be adjusted by a second adjustment screw that is screwed into the at least one second adjustment threaded hole and whose front end abuts against the retaining plate.

23. The optical line sensor as claimed in claim 12, wherein, The pair of retaining plates have fitting portions for fitting together and connecting the pair of retaining plates to each other.

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