Lens mirror array

Abstract

The technical problem of the present invention is to provide a lens mirror array in which optical elements having reflecting surfaces with high shape accuracy are arranged. The lens mirror array has a plurality of optical elements arranged in a main scanning direction. Each optical element has an incident surface, at least one reflective surface, an exit surface, a travel blocking portion, and a reflectance reducing unit. The incident surface transmits and converges incident light. The reflective surface has a positive optical magnification that reflects the light incident through the incident surface and converges the incident light. The emission surface emits the light reflected by the reflection surface. The travel blocking portion is provided between the reflective surface and a reflective surface of another optical element adjacent in the main scanning direction without a step difference. The reflectance reduction unit is provided in the travel blocking portion such that the reflectance of light in the travel blocking portion is smaller than that of the reflective surface.

Description

Technical Field

[0001] Embodiments of the present invention relate to a lens mirror array used in a scanner or an exposure device of an image forming apparatus such as a copier or a printer installed in a workplace. Background Art

[0002] For example, the scanner of the image forming device has a lens and mirror integrated array (hereinafter referred to as a lens-mirror array) for refracting and reflecting light reflected from the original surface and focusing it on a CCD sensor, etc. The lens-mirror array, for example, has a plurality of optical elements arranged in the main scanning direction. The lens-mirror array can be formed by, for example, integral molding of a transparent resin.

[0003] Each optical element has an incident side lens surface for incident reflected light from the original, an exit side lens surface for emitting the incident light toward the CCD sensor, and at least one reflecting surface for guiding the light incident via the incident side lens surface toward the exit side lens surface. In order to focus the light in the main scanning direction, the reflecting surface may have a travel blocking portion for blocking the light on both sides of the main scanning direction. Summary of the invention

[0004] For example, by making a part of the optical element protrude outward and providing a reflective surface on the top thereof, a light shielding film can be provided on the side of the protruding portion (the surface continuous with both sides of the reflective surface in the main scanning direction). In this case, the light shielding film provided on the side of the protruding portion becomes a travel-blocking portion. However, if such a protruding portion is provided on the optical element, the step difference on both sides of the reflective surface in the main scanning direction becomes larger, and when molding the lens reflector array, the flow of the resin is disturbed due to the step difference, making it difficult to ensure the shape accuracy of the reflective surface.

[0005] The technical problem to be solved by the present invention is to provide a lens reflector array in which optical elements having reflective surfaces with high shape accuracy are arranged.

[0006] The lens reflector array of the embodiment has a plurality of optical elements arranged in the main scanning direction. Each optical element has an incident surface, at least one reflecting surface, an exit surface, a travel-blocking portion, and a reflectivity reducing unit. The incident surface transmits and converges the incident light. The reflecting surface has a positive optical magnification for reflecting and converging the light incident through the incident surface. The exit surface emits the light reflected by the reflecting surface. The travel-blocking portion is arranged without a step difference between the reflecting surface and the reflecting surfaces of other optical elements adjacent to the main scanning direction. The reflectivity reducing unit is arranged in the travel-blocking portion so that the reflectivity of the light in the travel-blocking portion is smaller than that of the reflecting surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1This is a schematic diagram showing an image forming apparatus according to one embodiment.

[0008] Figure 2 Yes means Figure 1 A schematic diagram of an image forming unit of an image forming apparatus.

[0009] Figure 3 Yes means Figure 1 A cross-sectional view of a reading module of a scanner of an image forming device.

[0010] Figure 4 It means assembly in Figure 3 A stereoscopic view of the appearance of a lens reflector array according to a first embodiment of a reading module.

[0011] Figure 5 It is a local enlargement. Figure 4 A partial enlarged view of area F5 of the lens reflector array.

[0012] Figure 6 It is used to illustrate Figure 4 Diagram showing the functions and effects of the lens reflector array.

[0013] Figure 7 It is used to illustrate Figure 4 A diagram of appropriate values ​​of the pitch of the reflection surface on the downstream side of the lens reflector array and the width of the travel-stopping surface.

[0014] Figure 8 It is a perspective view showing the appearance of a lens reflector array according to the second embodiment.

[0015] Fig. 9 It is a local enlargement. Figure 8 A partial magnified view of area F9 of the lens reflector array.

[0016] Description of Reference Numerals

[0017] 1, 200: lens reflector array; 2: incident side lens surface; 3: upstream side reflection surface; 4: downstream side reflection surface; 5: exit side lens surface; 6: travel prevention surface; 61, 201: edge; 62, 202: shading film; 70: reading module; 78: holder; 100: image forming device. DETAILED DESCRIPTION

[0018] Hereinafter, an image forming apparatus 100 according to an embodiment will be described with reference to the accompanying drawings. It should be noted that the scales of the various parts of the various drawings used in the following description of the embodiment may be appropriately changed. In addition, the various drawings used in the following description of the embodiment may be omitted for easy understanding of the description.

[0019] The image forming device 100 of the present embodiment is, for example, an MFP (multifunction peripheral). The image forming device 100 has a printing function, a scanning function, a copying function, a decoloring function, a fax function, and the like. The printing function is a function of forming a toner image on a sheet of paper P. The scanning function is a function of reading an image from a manuscript on which an image is formed. The copying function is, for example, a function of printing an image read from a manuscript using a scanning function on a sheet of paper P using a printing function. The decoloring function is a function of decolorizing an image formed on the sheet of paper P using a decolorizable developer.

[0020] The image forming apparatus 100 includes a printer 10 , a scanner 20 , and an operation panel 30 .

[0021] The printer 10 includes a plurality of paper feed cassettes 11 , a manual feed tray 12 , and a plurality of paper feed rollers 13 . The paper feed cassettes 11 store paper P for printing. The manual feed tray 12 is used to manually feed paper P. The paper feed rollers 13 selectively take out paper P from either the paper feed cassettes 11 or the manual feed tray 12 by rotating.

[0022] The printer 10 includes four toner cartridges 141 , 142 , 143 , and 144 , four image forming units 151 , 152 , 153 , and 154 , an optical scanning device 16 , a transfer belt 17 , a secondary transfer roller 18 , and a fixing unit 19 .

[0023] The toner boxes 141 to 144 contain toners supplied to the image forming units 151 to 154, respectively. The toner box 141 contains yellow (Y) toner. The toner box 142 contains magenta (M) toner. The toner box 143 contains cyan (C) toner. The toner box 144 contains black (K) toner. The combination of toner colors is not limited to YMCK, and may be a combination of other colors. In addition, the toner may be a toner that is decolorized at a temperature higher than a specified temperature.

[0024] The image forming units 151 to 154 receive toner supply from the toner cartridges 141 to 144, respectively, and form toner images of different colors. The image forming unit 151 forms a toner image of yellow (Y). The image forming unit 152 forms a toner image of magenta (M). The image forming unit 153 forms a toner image of cyan (C). The image forming unit 154 forms a toner image of black (K).

[0025] The image forming units 151 to 154 have the same structure except for the difference in toner. Figure 2 , the image forming unit 151 for yellow is described as a representative, and descriptions of the image forming units 152 to 154 for other colors are omitted.

[0026] The image forming unit 151 for yellow includes a photosensitive drum 41 , a charging device 42 , a developing device 43 , a primary transfer roller 44 , a cleaner 45 , and an anti-static lamp 46 .

[0027] The photosensitive drum 41 has a surface that receives the light beam BY irradiated from the light scanning device 16. The light scanning device 16 forms an electrostatic latent image on the surface of the photosensitive drum 41. The charging device 42 charges the surface of the photosensitive drum 41 with positive charges. The developing device 43 develops the electrostatic latent image on the surface of the photosensitive drum 41 using the yellow toner D supplied from the toner box 141. That is, the developing device 43 forms a yellow toner image on the surface of the photosensitive drum 41.

[0028] The image forming unit 151 is provided with a primary transfer roller 44 at a position facing the photosensitive drum 41 with the transfer belt 17 interposed therebetween. The primary transfer roller 44 generates a transfer voltage between the primary transfer roller 44 and the photosensitive drum 41. Thus, the primary transfer roller 44 transfers (primary transfer) the toner image on the surface of the photosensitive drum 41 to the surface of the transfer belt 17 in contact with the photosensitive drum 41.

[0029] The cleaner 45 removes the toner remaining on the surface of the photosensitive drum 41. The charge removal lamp 46 removes the charge remaining on the surface of the photosensitive drum 41.

[0030] The optical scanning device 16 irradiates the surfaces of the photosensitive drums 41 of the image forming units 151, 152, 153, and 154 with light beams BY, BM, BC, and BK, respectively, based on the input image data. The light beams BY, BM, BC, and BK are based on image data obtained by color decomposing the image data into the respective colors Y, M, C, and K. The optical scanning device 16 emits the light beam BY based on the image data of the Y component, and forms an electrostatic latent image for yellow on the surface of the photosensitive drum 41 of the image forming unit 151. Similarly, the optical scanning device 16 emits the light beams BM, BC, and BK based on the image data of the M, C, and K components, and forms electrostatic latent images for the respective colors on the surfaces of the photosensitive drums 41 of the image forming units 152, 153, and 154.

[0031] The image data input to the optical scanning device 16 is, for example, image data read from a document by the scanner 20 . Alternatively, the image data input to the optical scanning device 16 is image data transmitted to the image forming device 100 from a device different from the image forming device 100 .

[0032] The transfer belt 17 is stretched in an endless shape and rotates by rotating a driving roller 171 around which the transfer belt 17 is wound. The transfer belt 17 conveys the toner images of various colors superimposed on the surface of the transfer belt 17 by the image forming units 151 to 154 to a transfer region facing the secondary transfer roller 18 by rotating.

[0033] The secondary transfer roller 18 faces the driving roller 171 with the transfer belt 17 interposed therebetween. The secondary transfer roller 18 transfers (secondary transfers) the toner image formed on the transfer belt 17 onto the paper P passing therebetween.

[0034] The fixing unit 19 heats and presses the paper P. The fixing unit 19 includes a heating roller 191 and a pressure roller 192 that face each other with the conveying path of the paper P sandwiched therebetween. The heating roller 191 includes a heat source such as a heater. The heating roller 191 heated by the heat source heats the paper P. The pressure roller 192 presses the paper P passing between the pressure roller 192 and the heating roller 191. Thus, the fixing unit 19 fixes the toner image transferred onto the paper P.

[0035] The printer 10 further includes a double-sided unit 50 and a paper discharge tray 60. The double-sided unit 50 enables printing on the back side of the paper P. The double-sided unit 50 reverses the front and back sides of the paper P by switching the paper P back and feeds the paper P to a transfer area between the transfer belt 17 and the secondary transfer roller 18. The paper discharge tray 60 is used to discharge the paper P after printing.

[0036] The scanner 20 reads an image from a document or the like. The scanner 20 includes a reading module 70 and a document feeding device 80 .

[0037] The reading module 70 irradiates illumination light to the surface of the document having the image to be read (hereinafter referred to as the document surface), and the image sensor 76 ( Figure 3 ) receives the reflected light and converts it into a digital signal. Thus, the reading module 70 reads the image from the original surface. The reading module 70 includes a lens reflector array 1.

[0038] The document feeding device 80 is, for example, an ADF (auto document feeder). The document feeding device 80 sequentially feeds documents placed on a document tray 81 via a document glass 82. The reading module 70 reads an image from the document fed to the document glass 82. The document feeding device 80 may also include another reading module for reading an image from the back side of the document.

[0039] The operation panel 30 is a human-machine interface for performing input and output between the image forming apparatus 100 and an operator of the image forming apparatus 100. The operation panel 30 includes, for example, a touch panel 31 and an input device 32.

[0040] The touch panel 31 is formed by laminating a display such as a liquid crystal display or an organic EL display and a pointing device based on touch input. The display of the touch panel 31 displays a screen for notifying the operator of the image forming apparatus 100 of various information. In addition, the touch panel 31 receives touch operations by the operator.

[0041] The input device 32 receives an operation of an operator of the image forming apparatus 100. The input device 32 is, for example, a keyboard, a keypad, or a touch panel.

[0042] like Figure 3 As shown, the reading module 70 includes the lens reflector array 1 involved in the first embodiment, two reflectors 72, two light guides 74, an image sensor 76, and a holder 78. The holder 78 positions and holds the lens reflector array 1, the reflectors 72, the light guides 74, and the image sensor 76 (the substrate 75 on which the image sensor 76 is mounted).

[0043] like Figure 4 As shown in FIG. 1 , the lens reflector array 1 has a strip structure extending in the main scanning direction (arrow direction). The lens reflector array 1 forms an erect image of the image on the document surface on the image sensor 76. Therefore, by moving the reading module 70 along the document glass 82, Figure 1 The image sensor 76 moves in the sub-scanning direction indicated by the middle arrow, so that the entire image on the document surface can be read.

[0044] The image sensor 76 has a strip structure extending in the main scanning direction. The image sensor 76 is a line sensor in which a plurality of imaging elements that convert light into electrical signals are arranged linearly in the main scanning direction. The image sensor 76 is one or more line sensors. The image sensor 76 can be composed of, for example, a Charge Coupled Device (CCD), a Complementary Metal Oxide Semiconductor (CMOS), or other imaging elements.

[0045] The retainer 78 has a long strip structure extending in the main scanning direction. The retainer 78 can be formed by integrally molding a resin using a mold. The retainer 78 has: a pair of side walls 781 arranged along the main scanning direction; a pair of end walls 782 (in the main scanning direction); Figure 3 The side walls 781 are provided with a plurality of partition walls 783, each of which is provided with a plurality of partition walls 784. The partition walls 783 are provided with a plurality of partition walls 784, each of which is provided with a plurality of partition walls 785. The partition walls 783 are provided with a plurality of partition walls 786, each of which is provided with a plurality of partition walls 787. The partition walls 783 are provided with a plurality of partition walls 788, each of which is provided with a plurality of partition walls 789, each of which is provided with a plurality of partition walls 781. The partition walls 783 are provided with a plurality of partition walls 784, each of which is provided with a plurality of partition walls 781. The partition walls 783 are provided with a plurality of partition walls 784, each of which is provided with a plurality of partition walls 783. The partition walls 783 are provided with a plurality of partition walls 784, each of which is provided with a plurality of partition walls 785. The partition walls 783 are provided with a plurality of partition walls 786, each of which is provided with a plurality of partition walls 787. The partition walls 783 are provided with a plurality of partition walls 788, each of which is provided with a plurality of partition walls 789, each of which is provided with a plurality of partition walls 781. The partition walls 783 are provided with a plurality of partition walls 784, each of which is provided with a plurality of partition walls 788. The partition walls 783 are provided with a plurality of partition walls 784, each of which is provided with a plurality of partition walls 789, each of which is provided with a plurality of partition walls 781. The partition walls 783 are provided with a plurality of partition walls 784, each of which is provided with a plurality of partition walls 785. The partition walls 783 are provided with a plurality of partition walls 784, each of which is provided with a plurality of partition walls

[0046] The bulging portion 784 of the holder 78 has a rectangular slit-shaped aperture opening 785 extending in the main scanning direction at the approximate center in the sub-scanning direction. The aperture opening 785 allows the reflected light from the original surface to pass through, reduces the width of the reflected light in the sub-scanning direction, and guides it to the lens reflector array 1. The holder 78 holds the lens reflector array 1 inside the bulging portion 784, that is, on the lower side of the aperture opening 785 in the figure. The width of the aperture opening 785 in the sub-scanning direction is larger than the width of the multiple incident side lens surfaces 2 ( Figure 4 The aperture opening 785 is configured so that the sub-scanning direction optical axis of the incident-side lens surface 2 passes through the center of the aperture opening 785 in the sub-scanning direction.

[0047] The holder 78 holds the reflector 72 and the light guide 74 on both sides sandwiching the bulging portion 784 along the sub-scanning direction, inside the two side walls 781 and above the partition wall 783. Illustration and description of the holding structure of the reflector 72 and the light guide 74 are omitted.

[0048] The reflector 72 is, for example, a long rectangular plate extending in the main scanning direction. The reflector 72 has a reflective surface facing the light diffusion portion (not shown) of the light guide 74 which is provided with concave and convex parts or coated with white ink. The reflector 72 is coated with white ink on its reflective surface, or a white resin is formed into a rectangular plate. The reflector 72 has a function of reflecting light leaking from the light diffusion portion of the light guide 74 and returning it to the light guide 74.

[0049] The light guide 74 is, for example, a transparent resin having a substantially cylindrical shape that is long in the main scanning direction, and has the light diffusion portion described above on a portion of its surface along the longitudinal direction. The light guide 74 guides light emitted from an LED light source (not shown) or the like disposed at one end in the longitudinal direction thereof. The reflector 72 reflects light leaking from the light diffusion portion of the light guide 74 and returns the light to the light guide 74.

[0050] Since the two light guides 74 have the bulging portion 784 of the partition wall 783 of the holder 78 between them, they need to be arranged at a certain distance from each other in the sub-scanning direction to prevent the bulging portion 784 from forming a shadow of the illumination light. On the other hand, if the two light guides 74 are separated in the sub-scanning direction, the angle of the illumination light irradiated to the image reading area on the manuscript surface becomes larger, and the change in illumination when the distance between the manuscript glass 82 and the manuscript surface changes becomes larger. Therefore, it is preferable that the two light guides 74 are arranged as close as possible in the sub-scanning direction.

[0051] The holder 78 has a plurality of bosses 786 that protrude downward from the lower surface of the partition wall 783. The bosses 786 are provided, for example, at the two ends of the partition wall 783 in the main scanning direction and three locations in the center, and on both sides of the bulging portion 784 in the sub-scanning direction. These six bosses 786 are used to fix the substrate 75 to the holder 78 using screws 787. It should be noted that the holder 78 has a plurality of bosses 788 for positioning the substrate 75 on the holder 78.

[0052] Below, refer to Figure 3 as well as Figure 4 The lens reflector array 1 is described. The lens reflector array 1 has a structure in which a plurality of transparent optical elements 90 of substantially the same shape are arranged in a main scanning direction and arranged integrally. The shape of the effective surface of each optical element 90 has a shape that is plane-symmetrical with respect to a virtual center plane that passes through the center of the main scanning direction of the optical element 90 and is orthogonal to the main scanning direction. Figure 3 In the figure, the direction perpendicular to the paper surface is the main scanning direction, and the left-right direction in which the reading module 70 moves is the sub-scanning direction. Figure 4 It is from Figure 3 A partially enlarged perspective view of a portion of the lens mirror array 1 viewed from the opposite side, with the main scanning direction indicated by an arrow.

[0053] The lens reflector array 1 has, in addition to the plurality of optical elements 90, extended portions (not shown) at both ends of the longitudinal direction thereof that can be touched by an operator when holding the lens reflector array 1. The lens reflector array 1 of this embodiment is formed by integral molding of a transparent resin. The lens reflector array 1 can also be formed of transparent glass.

[0054] Each optical element 90 of the lens reflector array 1 guides light in such a manner that diffused light from an object point is imaged at an imaging point located on the image plane. One optical element 90 images light from a plurality of object points arranged in the main scanning direction on the image plane. For example, one optical element 90 images light from object points arranged within a width of 2 to 5 times the pitch of the optical element 90 in the main scanning direction on the image plane. Each optical element 90 of the lens reflector array 1 reflects the incident light twice and emits it, forming an erect image of the object point at the imaging point.

[0055] Each optical element 90 of the lens reflector array 1 has an incident side lens surface 2 (incident surface), an upstream side reflection surface 3, a downstream side reflection surface 4 (at least one reflection surface) and an exit side lens surface 5 (exit surface) on its surface. The incident side lens surface 2, the downstream side reflection surface 4 and the exit side lens surface 5 are free-form surfaces convex to the outside. The upstream side reflection surface 3 is a flat surface. The other surfaces of the plurality of optical elements 90 respectively form a flat surface connected in the main scanning direction over the entire length of the lens reflector array 1.

[0056] The incident-side lens surface 2 of the optical element 90 faces the aperture opening 785 located in the bulged portion 784 of the holder 78. In other words, the lens reflector array 1 is formed in a region where the incident-side lens surface 2 of the plurality of optical elements 90 faces the aperture opening 785. Figure 3 In the state shown, it is fixed to the bulging portion 784. The incident side lens surface 2 has a positive optical power for refracting and converging the incident light reflected by the document surface and passing through the aperture 785.

[0057] The upstream side reflection surface 3 is adjacent to the side opposite to the protruding portion 91 with respect to the incident side lens surface 2. That is, the upstream side reflection surface 3 is located on the optical path of the incident light incident through the incident side lens surface 2. The upstream side reflection surface 3 totally reflects the light incident through the incident side lens surface 2 toward the downstream side reflection surface 4. The upstream side reflection surface 3 is located at the top of the protruding portion that makes a part of the optical element 90 protrude outward. The side surface of the protruding portion that is continuous with the outer side of the upstream side reflection surface 3 in the main scanning direction and the side surface of the protruding portion that is continuous with the end edge of the upstream side reflection surface 3 separated from the incident side lens surface 2 are coated with a light shielding film 33.

[0058] The downstream side reflection surface 4 is continuous with respect to the incident side lens surface 2 on the opposite side of the protruding portion 92. The downstream side reflection surface 4 is located on the optical path of the reflected light reflected by the upstream side reflection surface 3. The downstream side reflection surface 4 totally reflects the reflected light reflected by the upstream side reflection surface 3 toward the exit side lens surface 5. The downstream side reflection surface 4 is a free-form surface having a positive optical magnification for reflecting and converging the light. The width of the downstream side reflection surface 4 in the main scanning direction is narrower than the width of the optical element 90.

[0059] Figure 5 It is a magnified representation Figure 4 A partially enlarged stereoscopic image of a portion of area F5. The lens reflector array 1 has a plurality of roughly rectangular travel-blocking surfaces 6 (travel-blocking portions, processed surfaces) between the downstream side reflection surfaces 4 of the plurality of optical elements 90. The travel-blocking surface 6 is a roughly flat surface provided across two adjacent optical elements 90 in the main scanning direction, or it may be a cylindrical surface in which a line intersecting an imaginary surface orthogonal to the center plane of the optical element 90 and the travel-blocking surface 6 is continuous in a direction orthogonal to the main scanning direction, that is, a surface whose shape in the sub-scanning direction is a free-form surface and whose shape in the main scanning direction is a straight line (the shape does not change according to the position in the main scanning direction), so that the lens width is constant. By providing the travel-blocking surface 6 between the plurality of downstream side reflection surfaces 4, the range of the reflected light reflected by the downstream side reflection surface 4 can be limited.

[0060] The travel-blocking surface 6 is arranged without a step difference between the downstream-side reflective surface 4 of the optical element 90 and the downstream-side reflective surface 4 of another optical element 90 adjacent in the main scanning direction, and has a fine groove-shaped edge 61 (corner) between the downstream-side reflective surfaces 4 on both sides of the main scanning direction. A light-shielding film 62 (reflectivity reduction unit) is provided on the travel-blocking surface 6. The light-shielding film 62 is coated with UV-curable light-shielding ink and thermal-curable light-shielding ink and cured, and at least the light reflectivity is lower than that of the downstream-side reflective surface 4. The width of the light-shielding film 62 in the main scanning direction is the width of the edge 61 located at both ends of the travel-blocking surface 6 in the main scanning direction. That is, the width of the light-shielding film 62 in the main scanning direction is slightly larger than the width of the travel-blocking surface 6.

[0061] The edge 61 plays a role in attracting the light-shielding ink by the capillary phenomenon and making it easy to wet and spread to the travel-blocking surface 6. The edge 61 is located in the valley-shaped portion where the downstream-side reflecting surface 4 and the travel-blocking surface 6 intersect. Therefore, the shape of the edge 61 is a substantially V-shaped cross section in which the downstream-side reflecting surface 4 and the travel-blocking surface 6 are cut along the plane along the main scanning direction. Therefore, when the light-shielding ink is applied from one end side of the long side direction of the edge 61, the light-shielding ink is attracted along the edge 61 toward the other end side thereof, and is well wet and spread on the travel-blocking surface 6 located between the two edges 61.

[0062] The light-exiting lens surface 5 is located on the optical path of the reflected light reflected by the downstream reflecting surface 4. The light-exiting lens surface 5 has a positive optical power for transmitting and converging the reflected light reflected by the downstream reflecting surface 4.

[0063] It should be noted that the imaginary boundary surface ( Figure 4 The cross section) is a plane perpendicular to the main scanning direction, and is a plane substantially perpendicular to the above-mentioned surfaces 2, 3, 4, 5, and 6 of the optical element 90.

[0064] Next, the function of the above-mentioned lens mirror array 1 will be described.

[0065] The light reflected from the document surface enters the incident side lens surface 2 of the plurality of optical elements 90. That is, the reflected light from the document surface placed at the object point enters the incident side lens surface 2. The incident side lens surface 2 refracts and converges the incident light to form an intermediate inverted image.

[0066] The upstream reflection surface 3 reflects the incident light incident via the incident-side lens surface 2 toward the downstream reflection surface 4. The downstream reflection surface 4 further reflects the light reflected by the upstream reflection surface 3 toward the emission-side lens surface 5.

[0067] The exit-side lens surface 5 emits the light reflected by the downstream-side reflection surface 4 toward the image sensor 76 disposed at the imaging point. The exit-side lens surface 5 cooperates with the downstream-side reflection surface 4 to form an erected image as an inverted image of the intermediate inverted image formed by the incident-side lens surface 2. The exit light emitted from the exit-side lens surface 5 is imaged on the light-receiving surface of the image sensor 76 disposed at the imaging point.

[0068] Next, refer to Figure 6 as well as Figure 7 The following describes the function and effect of providing the travel preventing surface 6 between the downstream side reflecting surfaces 4 as in this embodiment. Figure 6 In (a), for comparison, the optical path of light passing through the lens reflector array 101 without the travel blocking surface 6 between the downstream side reflective surfaces 4 and without the light shielding film 62 between the downstream side reflective surfaces 4 is expanded into a plane to represent. Figure 6 In (b), the optical path of light passing through the lens reflector array 1 according to the first embodiment in which the light shielding film 62 is provided on the travel preventing surface 6 between the plurality of downstream reflecting surfaces 4 is developed as a plane.

[0069] As described above, one optical element 90 of the lens reflector array 1 forms an image on the image plane from light from a plurality of object points arranged in the main scanning direction. Figure 6 As shown, light from an object point is incident on a plurality of optical elements 90 arranged in the main scanning direction of the lens reflector array 1, and is imaged at an imaging point. The light from the object point is diffuse light, and the light guided in the lens reflector array 1 and emitted becomes light converging toward the imaging point. The light passing through the lens reflector array 1 is shaped by the shading film 33 located around the upstream side reflection surface 3 of each optical element 90 and the shading film 62 provided on the travel prevention surface 6 on both sides of the main scanning direction of the downstream side reflection surface 4. Therefore, among the plurality of optical elements 90 on which the light from an object point is incident, the light guided in several optical elements 90 on both sides of the main scanning direction is not imaged at the imaging point.

[0070] For example, in Figure 6In the lens reflector array 101 of the comparative example shown in (a), light from one object point is incident on nine optical elements arranged in the main scanning direction, and light emitted from the six central optical elements forms an image at an imaging point. In contrast, in the lens reflector array 1 of the first embodiment having a light shielding film 62 between the downstream side reflection surfaces 4, light from one object point is incident on nine optical elements 90 arranged in the main scanning direction, and light emitted from the four central optical elements 90 forms an image at an imaging point. That is, when the lens reflector array 1 of the present embodiment is used, the width of the downstream side reflection surface 4 in the main scanning direction is narrowed by the light shielding film 62 provided on the travel prevention surface 6, and the reflected light reflected by the downstream side reflection surface 4 is limited in the main scanning direction, so that the angle of the incident light reaching the image plane in the main scanning direction can be reduced, and the NA (numerical aperture) becomes small, which can increase the depth of field.

[0071] As in the lens reflector array 1 of the present embodiment, if the width of the downstream side reflection surface 4 in the main scanning direction is narrowed by providing the travel-blocking surface 6 and the light-shielding film 62, the number of optical elements 90 through which the light forming an image at one imaging point passes can be reduced, the contrast at the best position on the image plane can be increased, and the depth of field can also be increased. However, if the width of the travel-blocking surface 6 provided with the light-shielding film 62 is too large, the amount of light becomes too small, and if the width of the travel-blocking surface 6 is too small, there is no change from the comparative example. Therefore, there is an appropriate value for the width of the travel-blocking surface 6.

[0072] To investigate appropriate values, such as Figure 7 As shown, the pitch of the multiple downstream side reflection surfaces 4 in the main scanning direction is set to P [μm], the width of the travel blocking surface 6 in the main scanning direction is set to W [μm], and the ratio of P and W is changed to monitor the light imaged on the image plane. As a result, it can be seen that when the width W of the travel blocking surface 6 is set to 0.35 times to 0.95 times the pitch P of the downstream side reflection surface 4 (that is, the pitch of the optical element 90), good optical performance can be obtained. In this embodiment, W / P is designed to be in the range of 0.35 to 0.95, and the ratio of W to P is set so that the light guided by 3 to 5 optical elements 90 is imaged at one imaging point.

[0073] If the travel-blocking surface 6 is provided without forming a step difference between the downstream-side reflective surfaces 4 as in the lens reflector array 1 of the present embodiment, the resin of the portion corresponding to the edge 61 can flow smoothly when the lens reflector array 1 is molded, and the shape accuracy of the downstream-side reflective surface 4 can be improved. In addition, according to the lens reflector array 1 of the present embodiment, the capillary phenomenon of the edge 61 between the downstream-side reflective surface 4 and the travel-blocking surface 6 can be used to make the light-shielding ink wet and spread to the travel-blocking surface 6 well, and the shape of the light-shielding film 62 can be stabilized. Therefore, according to the present embodiment, the contrast at the best position in the image plane can be increased, the depth of field can be increased, and good optical performance can be obtained.

[0074] Figure 8 is a perspective view showing an enlarged portion of a lens reflector array 200 according to the second embodiment. Fig. 9 It is a local enlargement. Figure 8 An enlarged stereoscopic view of region F9 of lens reflector array 200.

[0075] The lens reflector array 200 has an edge 201 (corner) instead of having a travel-blocking surface 6 between the plurality of downstream-side reflective surfaces 4, and has a substantially similar structure to the lens reflector array 1 of the first embodiment described above, except that a light-shielding film 202 covering the edge 201 is provided between the downstream-side reflective surfaces 4 of two optical elements 90 adjacent in the main scanning direction. Therefore, the structure different from that of the lens reflector array 1 of the first embodiment described above is described here, and the same reference numerals are given to the components that function in the same manner as the lens reflector array 1 of the first embodiment, and their detailed description is omitted.

[0076] The downstream side reflection surface 4 is a free-form surface having a positive optical magnification for reflecting and converging the reflected light reflected by the upstream side reflection surface 3 toward the exit side lens surface 5, and is a surface bulging outward from the lens reflector array 200. The downstream side reflection surfaces 4 of two adjacent optical elements 90 in the main scanning direction are adjacent to each other with the edge 201 therebetween. That is, the width of the downstream side reflection surface 4 of the lens reflector array 200 in the present embodiment in the main scanning direction is substantially the same as the width of the optical element 90 in the main scanning direction.

[0077] The edge 201 is a concave groove provided at the intersection of two adjacent downstream side reflection surfaces 4 in the main scanning direction, and plays a role in attracting the light-shielding ink by capillary action, similar to the edge 61 of the lens reflector array 1 of the first embodiment. The lens reflector array 200 of this embodiment does not have the travel-stopping surface 6, so the light-shielding film 202 is formed to have a predetermined width in the main scanning direction and cover the edge 201.

[0078] As described above, according to the lens reflector array 200 of the second embodiment, as in the above-mentioned first embodiment, a plurality of downstream side reflection surfaces 4 arranged in the main scanning direction are continuous without step differences separated by edges 201, so that the flow of resin will not be disturbed during the molding of the lens reflector array 200, thereby being able to improve the shape accuracy of the downstream side reflection surface 4.

[0079] Although several embodiments are described, these embodiments are only presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the purpose of the invention. These embodiments and their variations are included in the scope and purpose of the invention, and are also included in the invention described in the claims and their equivalents.

Claims

1. A lens reflector array, characterized in that: having a plurality of optical elements arranged in a main scanning direction, The optical element has: The incident surface allows the incident light to pass through and converge; at least one reflecting surface having a positive optical power for reflecting light incident through the incident surface and converging the incident light; an emitting surface for emitting the light reflected by the reflecting surface; a travel preventing portion provided without a step difference between the reflecting surface and the reflecting surface of the other adjacent optical element in the main scanning direction; as well as The reflectivity reducing unit is provided in the progress preventing portion so that the reflectivity of light in the progress preventing portion is lower than that of the reflecting surface.

2. The lens reflector array according to claim 1, wherein: The travel preventing portion includes a corner portion that generates a capillary phenomenon at an end portion of the reflecting surface in the main scanning direction.

3. The lens reflector array according to claim 2, wherein: The travel preventing portion includes a processed surface which is continuous with two reflecting surfaces without a step difference via the corner of the reflecting surface of one of the optical elements and the corner of the reflecting surface of the other optical element adjacent to each other in the main scanning direction.

4. The lens reflector array according to claim 3, wherein: The width of the processed surface in the main scanning direction is a width at which light from one object point is guided by three to five adjacent optical elements and imaged at one imaging point.

5. The lens reflector array according to claim 2, wherein: The travel preventing portion has one corner portion at a location where the reflection surface of one of the optical elements and the reflection surface of the other optical element adjacent to each other in the main scanning direction intersect.

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