JP2019114403A - Light-emitting device, image-reading device, image-forming device, and method for manufacturing light-guiding body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine the ratio (illumination rate) of the amount of light irradiated to an object through the light guide to the amount of light emitted from a light emitting element, as compared with the case where a reflective layer is directly formed on the light guide. Provided are a light emitting device, an image reading device, an image forming device, and a method of manufacturing a light guide, which can be increased in height. A reflective layer 182 has a transmissive layer 182 formed on a surface of a light guide body 140, the refractive index of light of which is larger than that of a material forming the light guide body 140 and which is formed of a material that transmits light. It is formed on the surface of the light guide body 140 so as to be sandwiched therebetween. [Selection diagram] Figure 1

Description

  The present invention relates to a light emitting device, an image reading device, an image forming device, and a method of manufacturing a light guide.

  The linear light source described in Patent Document 1 includes a linear light guide, a light emitting unit coupled to introduce light into the light guide, and a light scattering unit formed on a side surface of the light guide. It consists of

Japanese Patent Application Publication No. 07-245676

  The problem of the present invention is that the ratio of the amount of light emitted to the object through the light guide to the amount of light emitted from the light emitting element is smaller than the case where the reflective layer is formed directly on the light guide To increase the rate).

  A light emitting device according to a first aspect of the present invention comprises a light guide extending in one direction, a light emitting element disposed opposite to an end face of the light guide and irradiating the end face with light, and a refractive index of light Is formed on the surface of the light guide with a transparent layer formed on the surface of the light guide being interposed between the material forming the light guide and a material that transmits light, which is larger than the material forming the light guide, And a reflective layer for reflecting light toward the inside of the light guide.

  A light emitting device according to a second aspect of the present invention is the light emitting device according to the first aspect, wherein the refractive index of light of the material forming the transmission layer is at least up to the central portion in one direction of the light guide. It is characterized in that it is enlarged as it goes away from the light emitting element.

  A light emitting device according to a third aspect of the present invention is the light emitting device according to the second aspect, wherein the light guide has a cylindrical shape, and a plurality of the transmissive layers are arranged at intervals in the one direction. In the plurality of transmission layers, the lengths of the light guides in the circumferential direction are the same.

  A light emitting device according to a fourth aspect of the present invention is the light emitting device according to any one of the first to third aspects, further comprising: a case for housing the light guide, wherein the case is the light guide And a part of the light guide in one direction is held in one place.

  A light emitting device according to a fifth aspect of the present invention is the light emitting device according to the fourth aspect, wherein the housing holds the light guide across the central portion in the one direction of the light guide. It is characterized by

  In the image reading apparatus according to a sixth aspect of the present invention, the light emitting element emits light to an end face of the light guide and emits light from the surface of the light guide toward an object on which an image is formed. The light emitting device according to any one of claims 1 to 5, the plurality of light receiving elements arranged in one direction, and the light reflected from the object on which an image is formed. And a guiding member for guiding.

  According to a seventh aspect of the present invention, there is provided an image forming apparatus comprising: the image reading apparatus according to the sixth aspect; and an image forming unit for forming an image based on image information read by the image reading apparatus. It features.

  In the method of manufacturing a light guide according to claim 8 of the present invention, the refractive index of light is larger than that of the material forming the light guide and the light is transmitted on the surface of the light guide extending in one direction. And a first application step of applying the transmission material to form a transmission layer by an inkjet method, and the surface of the transmission material applied to the surface of the light guide is the surface of the light guide And curing the transmission material to form a transmission layer, and a second application step of applying a reflection material to form a reflection layer on the surface of the transmission layer at least the surface of which has been cured, by an inkjet method And.

  According to the light emitting device of claim 1 of the present invention, the object is irradiated through the light guide with respect to the amount of light emitted from the light emitting element as compared with the case where the reflective layer is formed directly on the light guide. Ratio (illumination rate) can be increased.

  According to the light emitting device of claim 2 of the present invention, the amount of light for reflecting light per unit area of the reflective layer is smaller than when the refractive index of the light of the material forming the transmissive layer is the same at all parts. It is possible to suppress the decrease as the distance from the light emitting element is increased.

  According to the light emitting device of claim 3 of the present invention, it is possible to easily find a defect with respect to the shape of the transmission layer visually as compared with the case where the lengths in the circumferential direction of the light guide differ in the plurality of transmission layers. it can.

  According to the light emitting device of claim 4 of the present invention, the light guide is guided when the light guide expands and contracts due to temperature change, as compared with the case where both ends of the light guide are sandwiched by the casing. It is possible to suppress deformation in the radial direction of the light body.

  According to the light emitting device of claim 5 of the present invention, one end of the light guide when the light guide expands and contracts due to a temperature change as compared with the case where the one end of the light guide is sandwiched by the housing It is possible to suppress the difference between the moving amount of the part and the moving amount of the other end.

  According to the image reading apparatus of the sixth aspect of the present invention, it is possible to suppress a decrease in the reading accuracy for reading the image of the original as compared with the case where the reflective layer is formed directly on the light guide.

  According to the image forming apparatus of claim 7 of the present invention, it is possible to suppress deterioration in the quality of the output image as compared with the case where the reflective layer is formed directly on the light guide.

  According to the method for producing a light guide of claim 8 of the present invention, it is possible to suppress the dispersion between the position for applying the transmitting material and the position for applying the reflecting material, as compared with the case of using the screen printing method. it can.

FIG. 1 is a cross-sectional view showing an image reading device and a light emitting device according to a first embodiment of the present invention. FIG. 1 is a cross-sectional view showing an image reading device and a light emitting device according to a first embodiment of the present invention. FIG. 1 is a cross-sectional view showing an image reading device and a light emitting device according to a first embodiment of the present invention. FIG. 1 is a cross-sectional view showing an image reading device and a light emitting device according to a first embodiment of the present invention. (A) (B) It is an explanatory view used for explaining the reflective performance of the image reading device concerning a 1st embodiment of the present invention, and the image reading device concerning a 1st comparative form. FIG. 2 is an enlarged perspective view showing a case of the image reading apparatus according to the first embodiment of the present invention. FIG. 2 is an enlarged perspective view showing a case of the image reading apparatus according to the first embodiment of the present invention. FIG. 1 is an overall perspective view showing a case of an image reading apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective view showing a reflecting member of the image reading apparatus according to the first embodiment of the present invention. FIG. 1 is a cross-sectional view showing an image reading apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective view showing a light guide of the image reading apparatus according to the first embodiment of the present invention. FIG. 2 is a perspective view showing a light guide of the image reading apparatus according to the first embodiment of the present invention. FIG. 1 is a perspective view showing an image reading apparatus according to a first embodiment of the present invention. FIG. 1 is an exploded perspective view showing an image reading apparatus according to a first embodiment of the present invention. It is explanatory drawing used to demonstrate the manufacturing method of the light guide with respect to 1st Embodiment of this invention. It is sectional drawing which showed the light guide manufactured by the manufacturing method of the light guide which concerns on 1st Embodiment of this invention. (A) (B) It is sectional drawing which showed the light guide manufactured by the manufacturing method of the light guide which concerns on the 2nd comparative form of this invention. It is sectional drawing which showed the light guide of the light-emitting device based on the 1st comparison form of this invention. FIG. 2 is a cross-sectional view showing an image reading unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 2 is a perspective view showing an image reading unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 2 is a perspective view showing an image reading unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 2 is a configuration diagram showing an image reading unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 2 is a configuration diagram showing an image reading unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 1 is a configuration diagram showing an image forming apparatus according to a first embodiment of the present invention. It is the perspective view which showed the light guide of the image reader which concerns on 2nd Embodiment of this invention. It is sectional drawing which showed the light guide of the image reader based on 2nd Embodiment of this invention.

First Embodiment
An example of a light emitting device, an image reading device, an image forming device, and a method of manufacturing a light guide according to the first embodiment of the present invention will be described with reference to FIGS. In the drawings, an arrow H indicates the apparatus vertical direction (vertical direction), an arrow W indicates the apparatus width direction (horizontal direction), and an arrow D indicates the apparatus depth direction (horizontal direction).

(Whole configuration of image forming apparatus)
In the image forming apparatus 10, as shown in FIG. 24, in the accommodating portion 14 in which the sheet member P as a recording medium is accommodated from the lower side to the upper side in the vertical direction (arrow H direction), An image forming unit 20 configured to form an image on a sheet member P transported by the transporting unit 16 from the storage unit 14 and an image reading unit configured to scan an image formed on a document G Parts 60 are provided in this order.

[Accommodating section]
The housing portion 14 is provided with a housing member 26 which can be pulled out from the housing 10A of the image forming apparatus 10 to the front side in the apparatus depth direction, and the sheet member P is stacked on the housing member 26. Further, the storage unit 14 is provided with a delivery roll 30 for delivering the uppermost sheet member P stacked on the storage member 26 to the transport path 28 constituting the transport unit 16.

[Transporter]
The transport unit 16 is provided with a plurality of transport rolls 32 that transport the sheet member P along the transport path 28.

[Image Forming Unit]
The image forming unit 20 includes four image forming units 18Y, 18M, 18C, and 18K of yellow (Y), magenta (M), cyan (C), and black (K). In the following description, when it is not necessary to distinguish between Y, M, C, and K, Y, M, C, and K may be omitted.

  The image forming units 18 of the respective colors are detachably attachable to the housing 10A. The image forming unit 18 of each color is provided with an image carrier 36, a charging roll 38 for charging the surface of the image carrier 36, and an exposing device 42 for irradiating the charged image carrier 36 with exposure light. It is done. Further, in the image forming unit 18 of each color, the developing device 40 develops the electrostatic latent image formed by exposing the image carrier 36 charged with the exposure device 42 described above and visualizes it as a toner image. It is equipped.

  Further, in the image forming unit 20, an endless transfer belt 22 which circulates in the direction of arrow A in the figure, and a primary transfer roll 44 for transferring a toner image formed by the image forming unit 18 of each color to the transfer belt 22. It is equipped. Further, in the image forming unit 20, the secondary transfer roll 46 for transferring the toner image transferred to the transfer belt 22 to the sheet member P and the sheet member P to which the toner image is transferred are heated and pressed to A fixing device 50 for fixing the sheet member P is provided.

[Image reader]
As shown in FIG. 22, the image reading unit 60 has a first transparent plate 62 (so-called platen glass) on which the document G is placed when reading an image of a single document G, and an apparatus width of the first transparent plate 62. And a second transparent plate 72 disposed in one of the directions (left in the figure). The first transparent plate 62 and the second transparent plate 72 are fitted in the upper portion of the housing 60A of the image reading unit 60.

  An open / close cover 66 for opening or closing the first transparent plate 62 and the second transparent plate 72 is disposed above the first transparent plate 62 and the second transparent plate 72. Then, inside the opening / closing cover 66, the conveyance device 64 (for conveying the plurality of originals G along the conveyance path 70 in the opening / closing cover 66 and passing the original reading position R above the second transparent plate 72) A so-called ADF device is provided.

  Further, the inside of the case 60A is provided with the image reading device 100 for reading the image of the document G placed on the first transparent plate 62 and the image of the document G conveyed to the document reading position R by the conveyance device 64. It is done. Furthermore, the image reading unit 60 includes a drive device 74 that drives the image reading device 100 in the apparatus width direction.

  As shown in FIGS. 20 and 21, the driving device 74 is attached to the shaft 76 extending in the apparatus width direction (the moving direction of the image reading apparatus 100) and the lower surface of the housing 60A of the image reading apparatus 100. And a sliding member 78 slidably supported on the shaft 76.

  Furthermore, the drive device 74 includes a motor 80, a drive pulley 84 that is driven to rotate by receiving drive power from the motor 80, a driven pulley 86 that is driven to rotate, an endless belt wound around the drive pulley 84 and the driven pulley 86. And an endless belt 82. The drive pulley 84 is attached to one end of the shaft 76, and the driven pulley 86 is attached to the other end of the shaft 76.

  The sliding member 78 is attached to a portion on the center side in the device depth direction on the lower surface of the housing 60A, as shown in FIG. The sliding member 78 extends in the vertical direction and slides with the slit 78A into which a part of the endless belt 82 is fitted, and in a semicircular shape as viewed in the apparatus width direction, as shown in FIG. A sliding surface 78B is formed.

  Further, as shown in FIG. 21, the housing 60A is integrally formed with the housing 60A with a pair of support portions 90 for supporting the portions on both ends of the shaft 76 from the lower side. The details of the image reading apparatus 100 will be described later.

(Function of image forming apparatus)
In the image forming apparatus 10, an image is formed as follows.
First, the image reading unit 60 reads the image of the document G. Specifically, when the image of the document G conveyed by the conveyance device 64 is read, as shown in FIG. 23, the image reading device 100 drives the motor 80 (see FIG. 21) to drive the endless belt 82. The signal is transmitted via the first position, moves to the conveyance reading position on one side in the apparatus width direction, and is stopped. Then, the image reading apparatus 100 disposed at the conveyance reading position reads the image of the document G conveyed by the conveyance device 64.

  On the other hand, when reading the image of the document G placed on the first transparent plate 62, as shown in FIG. 22, the image reading apparatus 100 disposed at the reading start position (solid line in the figure) While reading the image of the document G, it moves in the device width direction along the first transparent plate 62 toward the reading end position (two-dot chain line in the drawing).

  Subsequently, based on the image information read by the image reading unit 60, the exposure device 42 irradiates exposure light to the surface of the image carrier 36 of each color charged by the charging roll 38 to form an electrostatic latent image ( See Figure 24).

  Thereby, an electrostatic latent image corresponding to the data is formed on the surface of the image carrier 36 of each color. Further, the developing device 40 of each color develops the electrostatic latent image and visualizes it as a toner image. Further, the toner image formed on the surface of the image carrier 36 of each color is transferred to the transfer belt 22 by the primary transfer roll 44.

  Therefore, the sheet member P fed from the accommodation member 26 to the conveyance path 28 by the delivery roll 30 is fed to the transfer position T where the transfer belt 22 and the secondary transfer roll 46 contact. At the transfer position T, the sheet member P is conveyed between the transfer belt 22 and the secondary transfer roll 46, whereby the toner image on the surface of the transfer belt 22 is transferred to the sheet member P.

  The toner image transferred to the sheet member P is fixed to the sheet member P by the fixing device 50. Then, the sheet member P on which the toner image is fixed is discharged by the conveyance roll 32 to the outside of the housing 10A.

(Main part configuration)
Next, the image reading apparatus 100 will be described.

  The image reading apparatus 100 (see FIG. 13) is configured to read an image formed on a document G (target object) using a known CIS (Contact Image Sensor) method. Then, as shown in FIG. 14, the image reading apparatus 100 includes a light receiving substrate 102, a pair of wiring cables 104 connected to the light receiving substrate 102, and a pair of substrates 106 respectively connected to the wiring cable 104. Is equipped. Further, the image reading apparatus 100 includes a light emitting element 128 mounted on a substrate 106, a pair of light guides 140 (light guides) in a cylindrical shape, a rod lens array 112 in a rectangular parallelepiped shape, and a housing 150. And have. The image reading apparatus 100 further includes a pair of reflecting members 120 surrounding the light guide 140, a layered portion 180 (see FIG. 11) formed on the surface of the light guide 140, and an upper surface of the housing 150. And a covering glass plate 118. The rod lens array 112 is an example of a guide member.

  A light emitting device 110 configured to emit light toward the document G is configured including the housing 150, the light guide 140, the layered portion 180, the light emitting element 128, and the substrate 106.

[Light guide 140]
As shown in FIG. 14, a pair of light guides 140 is provided, and the pair of light guides 140 are arranged in the device width direction. Furthermore, the pair of light guides 140 is accommodated in a light guide accommodating portion 150A (see FIGS. 1 and 8) of the casing 150, which is to be described later, while being held by the pair of reflecting members 120 respectively. Then, as shown in FIG. 1, the pair of light guides 140 are symmetrical to each other with respect to a central plane M1 that passes through the center C1 of the image reading device 100 and faces in the device width direction. Hereinafter, the light guide 140 on one side in the device width direction (left side in FIG. 1) will be described.

  As shown in FIG. 1 and FIG. 12, the light guide 140 has a cylindrical main body 142 extending in the device depth direction, and a protrusion 144 protruding from the surface (outer peripheral surface) of the main body 142. It is integrally formed of a transparent resin material (for example, acrylic resin). The device depth direction is an example of one direction.

  The protrusion 144 is on the upper side at the central portion in the longitudinal direction of the main body portion 142 (light guide 140) and from the portion on the outer side in the device width direction (opposite to the center plane M1) to the outer side in the device width direction. It protrudes. And the inclined surface 144A inclined so that it may be located in the lower part as it goes to a front end is formed in the part by the side of the front end of the protrusion part 144. As shown in FIG. Here, the central portion of the light guide 140 means a central portion (region) when the light guide 140 is divided into three in the longitudinal direction, but preferably, the light guide 140 may be five or more in the longitudinal direction. It is the central part (area) when divided.

[Reflecting member 120]
As shown in FIG. 14, a pair of reflecting members 120 is provided, and the pair of reflecting members 120 are arranged in the device width direction. Furthermore, the pair of reflection members 120 is accommodated in a light guide accommodating portion 150A (see FIGS. 1 and 8) of the casing 150, which is described later, with the pair of light guides 140 held therein. And a pair of reflective members 120 are made into the shape and arrangement which become mutually symmetrical with respect to central plane M1, as shown in FIG. Hereinafter, the reflecting member 120 on one side (left side in FIG. 1) in the device width direction will be described.

  As shown in FIGS. 1 and 9, the reflecting member 120 extends in the device depth direction, and is integrally formed of a white resin material (for example, a polycarbonate resin). The cross section of the reflection member 120 is U-shaped in which the inner side (central plane M1 side) in the device width direction is open, and the plate surface is connected to the bottom plate 122 facing the device width direction and the end of the bottom plate 122 It has side plates 124 and 126 whose plate surfaces are directed vertically. The side plate 126 is disposed below the side plate 124, and the tip of the side plate 126 protrudes inward in the device width direction relative to the tip of the side plate 124. The length in the device depth direction of the reflecting member 120 and the length in the device depth direction of the light guide 140 are the same.

  Then, with the light guide 140 disposed inside the reflecting member 120, the surface of the light guide 140 contacts the plate surface of the bottom plate 122, and the surface of the light guide 140 contacts the plate surface of the side plate 126. It is supposed to be. Furthermore, the surface of the light guide 140 is in contact with the tip of the side plate 124 in this state.

  In addition, the light guide 140 is disposed inside the reflection member 120 in contact with the surface of the light guide 140 at both end portions in the device depth direction on the side plate 126 and at the inner side in the device width direction. Protrusions 126A for holding the state are each formed to project upward (see FIG. 2). Thereby, the light guide 140 is held in the inside of the reflection member 120 in a stable posture. Further, in the central portion of the side plate 126 in the device depth direction, a recessed portion 126 B is formed in which the tip of the side plate 126 is recessed relative to the other portions.

  Further, in the central portion in the device depth direction of the reflection member 120, a through hole 120A penetrating from the inside to the outside of the reflection member 120 is formed in a portion straddling the bottom plate 122 and the side plate 124. With the light guide 140 disposed inside the reflecting member 120, as shown in FIG. 1, the protrusion 144 of the light guide 140 is inserted into the through hole 120A. Then, in this state, the inclined surface 144A of the protrusion 144 is exposed to the outside of the reflection member 120. The length in the apparatus depth direction of the through hole 120A is longer than the length in the apparatus depth direction of the protrusion 144.

  In this configuration, when the temperature changes while the reflective member 120 holds the light guide 140, the light guide 140 expands and contracts in the device depth direction. That is, although the protruding portion 126A of the reflecting member 120 holds the state in which the light guide 140 is disposed inside the reflecting member 120, the expansion and contraction of the light guide 140 in the longitudinal direction is not restricted.

[Rod lens array 112]
The rod lens array 112 is housed in a lens housing 150B (see FIGS. 1 and 8) of the housing 150, which will be described later. The outer shape of the rod lens array 112 is, as shown in FIG. 14, a rectangular solid extending in the device depth direction. In the rod lens array 112, a plurality of rod lenses (not shown) extending in the vertical direction are formed side by side in the device depth direction.

[Glass plate]
The glass plate 118 is disposed to cover the top surface of the housing 150 (see FIG. 10). As shown in FIG. 14, the glass plate 118 has a rectangular shape in which the plate surface is directed in the vertical direction and extends in the device depth direction as viewed from above.

[Light receiving substrate 102]
As shown in FIG. 1, the light receiving substrate 102 is disposed in contact with the lower surface of the support plate 156 formed on the housing 150. The light receiving substrate 102 has a plate surface facing in the vertical direction, and a plurality of light receiving elements 108 aligned in the device depth direction are mounted on the upper surface of the light receiving substrate 102 (see FIG. 14).

[Wiring cable 104]
The wiring cables 104 are provided as a pair, and as shown in FIG. 14, are so-called flexible flat cables whose base ends are connected to both ends in the device depth direction of the light receiving substrate 102. The base end of one wiring cable 104 is connected to the end on the back side (right side in the figure) of the light receiving substrate 102 in the device depth direction, and the base end of the other wiring cable 104 is the device depth of the light receiving substrate 102. It is connected with the end of the near side (left side in the figure) of the direction.

[Substrate 106, Light-Emitting Element 128]
The substrates 106 are provided in a pair, and are connected to the tip of the wiring cable 104 as shown in FIG. The plate surfaces of the pair of substrates 106 face in the device depth direction, and are separated from each other in the device depth direction.

  The light emitting elements 128 are mounted two by two on the substrate 106. Specifically, the two light emitting elements 128 are mounted on the surface of the one substrate 106 facing the other substrate 106, and are aligned in the device width direction.

[Case 150]
The housing 150 extends in the device depth direction as shown in FIGS. 8 and 14. Specifically, in the case 150, the plate surface faces in the device depth direction, and is connected to the pair of side plates 152 separated in the device depth direction and both ends of the pair of side plates, and the plate surface faces in the device width direction, It has a pair of side plates 154 spaced apart in the device width direction. Furthermore, the housing 150 includes a support plate 156 which is surrounded by the pair of side plates 152 and the pair of side plates 154 and whose plate surfaces face in the vertical direction. The support plate 156 is arranged to divide the space enclosed by the pair of side plates 152 and the pair of side plates 154 in the vertical direction.

  Further, inside the housing 150, a pair of light guide housings 150A in which the light guides 140 supported by the reflection member 120 are housed, and a lens housing 150B in which the rod lens array 112 is housed. And are formed. Furthermore, inside the housing 150, a pair of substrate accommodating portions 150C in which the substrates 106 are respectively accommodated are formed so as to sandwich the light guide accommodating portion 150A in the device depth direction.

-Light guide housing 150A-
As shown in FIGS. 2 and 8, the light guide housing portions 150A are formed in a pair in the apparatus width direction on the upper side with respect to the support plate 156, and extend in the apparatus depth direction. The pair of light guide housings 150A are symmetrical to each other with respect to the center plane M1. Furthermore, the respective light guide housing portions 150A are symmetrical to each other with respect to a center plane M2 (see FIG. 8) which passes through the center C1 of the image reading device 100 and is directed in the device depth direction. Hereinafter, the light guide housing portion 150A on one side (the left side in FIG. 2) in the device width direction will be described.

  As shown in FIGS. 2 and 7, a partition plate 158 is formed at the light guide housing portion 150A at the inner side in the apparatus width direction to rise from the support plate 156 and partition it from the lens housing portion 150B. There is. The partition plate 158 has a rectangular shape extending in the device depth direction when the plate surface faces the device width direction and viewed from the device width direction. The end of the partition plate 158 in the device depth direction is separated from the side plate 152 in the device depth direction. As shown in FIG. 2, a partition plate 158 for partitioning the light guide housing portion 150A and the lens housing portion 150B on one side in the apparatus width direction, and the light guide housing portion 150A on the other side in the device width direction. A partition plate 158 that separates from the lens housing portion 150B is separated in the apparatus width direction.

  Then, on the surface of the partition plate 158 facing the outer side in the apparatus width direction at the central part in the apparatus depth direction, a protrusion 158A that contacts the surface of the light guide 140 accommodated in the light guide housing 150A is formed. (See Figure 1 and Figure 6).

  Further, as shown in FIG. 1 and FIG. 6, a pressing portion 160 for pressing the light guide 140 against the projecting portion 158A rises from the support plate 156 at a position facing the projecting portion 158A in the device width direction. . The pressing portion 160 is L-shaped as viewed in the apparatus depth direction, and has a base 160A extending in the vertical direction, and a bending portion 160B bent from the tip of the base 160A and extending inward in the device width direction. doing.

  Further, on the bent portion 160B, a contact surface 160C which is in contact with the inclined surface 144A formed on the projecting portion 144 of the light guide 140 is formed. The base portion 160A of the pressing portion 160 is elastically deformed in a state where the contact surface 160C of the pressing portion 160 is in contact with the inclined surface 14A of the projecting portion 144 of the light guide 140.

  In this configuration, the pressing unit 160 presses the light guide 140 against the protrusion 158A of the housing 150 in the device width direction. Further, the pressing unit 160 presses the light guide 140 against the support plate 156 of the housing 150 via the side plate 126 of the reflection member 120 in the apparatus vertical direction. As described above, the pressing unit 160 of the housing 150 holds a part of the light guide 140 in the housing 150 at one place, sandwiching the light guide 140 from the cross direction intersecting the device depth direction. Specifically, the pressing unit 160 of the housing 150 holds the light guide 140 in the housing 150 with the central portion (a part of the central portion) of the light guide 140 in the device depth direction interposed therebetween. In the state where the light guide 140 is held by the housing 150, the base 160A of the pressing unit 160 and the reflecting member 120 are separated in the device width direction.

  Further, as shown in FIG. 7, in the partition plate 158, a projection 158B in contact with the tip of the side plate 126 of the reflection member 120 is provided between the projection 158A and the longitudinal end of the partition 158. A plurality is formed at intervals in the depth direction (see FIG. 3).

  Specifically, the protrusion 158B protrudes from the surface of the divider plate 158 facing outward in the device width direction. The distance between the protrusion 158B arranged closest to the protrusion 158A and the protrusion 158A, the distance between the protrusion 158B arranged closest to the end of the partition plate 158 and the end of the partition plate 158, and the protrusion The protrusions 158B are disposed such that the intervals between the portions 158B are the same.

  Further, as shown in FIG. 7, a pressing portion 162 for pressing the reflecting member 120 against the projecting portion 158B rises from the support plate 156 at a position shifted from the projecting portion 158B in the device width direction. As shown in FIG. 2, the pressing portion 162 is elastically deformed in a state of being in contact with the bottom plate 122 of the reflecting member 120 from the outside in the device width direction.

  Further, as shown in FIG. 7, the holding portion 166 for holding the reflecting member 120 is supported so as to be aligned with the pressing portion 162 in the device width direction at a position shifted from the projecting portion 158B in the device width direction. Stand up from the plate 156. As shown in FIG. 4, the holding portion 166 is L-shaped when viewed from the depth direction of the device, and is bent from the tip portion of the base portion 166A and the tip portion of the base portion 166A extending in the vertical direction and extends inward in the device width direction. And a bent portion 166B. The tip of the bent portion 166B is in contact with the side plate 124 of the reflecting member 120 from the upper side.

  In this configuration, the pressing unit 162 presses the reflecting member 120 against the protrusion 158B in the device width direction (see FIG. 3). Further, the holding unit 166 holds the reflection member 120 by restricting the upward movement of the reflection member 120 in the apparatus vertical direction. Thus, the reflection member 120 is held by the housing 150.

-Lens housing 150B-
As shown in FIGS. 1 and 8, the lens housing portion 150B is formed between the pair of light guide housing portions 150A in the apparatus width direction, and extends in the device depth direction. Specifically, the lens housing portion 150B is formed between the pair of partition plates 158. In the lens housing portion 150B, the support plate 156 penetrates upward and downward. Further, in the device depth direction, both end portions of the lens housing portion 150B are separated from the side plate 152 in the device depth direction.

  In this configuration, the lens housing portion 150B sandwiched between the pair of partition plates 158 houses the rod lens array 112, and the rod lens array 112 is fixed to the lens housing portion 150B by a fixing member (not shown). .

-Substrate storage unit-
As shown in FIG. 14, a pair of substrate accommodating portions 150C is formed on the back side and the front side in the device depth direction with respect to the light guide body accommodating portion 150A. Specifically, as shown in FIG. 10, the substrate housing portion 150C is formed between the side plates 152 at both ends in the device depth direction of the housing 150 and the light guide housing portion 150A. In the portion 150C, a part of the support plate 156 penetrates in the vertical direction.

  In this configuration, the substrate accommodation unit 150C accommodates the substrate 106 on which the light emitting element 128 is mounted. In this state, the light emitting element 128 faces the light guide 140 end face 140A, and is in contact with the end face 140A of the light guide 140. That is, the light emitting element 128 is in contact with both end faces 140A of the light guide 140, respectively.

-Other-
At the top of the housing 150, as shown in FIGS. 1 and 10, a step 153 supporting the edge of the glass plate 118 from below is formed. In this configuration, the glass plate 118 is fixed to the housing 150 by fixing means (not shown) in a state where the edge of the glass plate 118 is in contact with the step 153 of the housing 150 and covers the upper surface of the housing 150. There is.

  Further, on the lower surface of the support plate 156 of the housing 150, as shown in FIG. 1, a pair of projecting portions 168 are formed so as to project downward across the center plane M1. The pair of protrusions 168 extends in the device depth direction, and both end portions of the pair of protrusions 168 are separated from the side plate 152 (see FIG. 14) of the housing 150 in the device depth direction. In this configuration, the light receiving substrate 102 is fixed to the housing 150 by fixing means (not shown) in a state of being in contact with the lower surface of the support plate 156 between the pair of protrusions 168. Then, in this state, the light receiving element 108 mounted on the light receiving substrate 102 is opposed to the rod lens array 112 in the vertical direction.

[Layered portion 180]
The layer portion 180 is, as shown in FIG. 1, on the surface of the light guide 140 opposite to the side facing the portion of the glass plate 118 above the rod lens array 112 (arrow B side in the figure) It is formed. The layered portion 180 is disposed so as not to be in contact with the reflecting member 120. That is, the layered portion 180 is prevented from being damaged by coming into contact with the reflecting member 120.

  Furthermore, as shown in FIG. 11, a plurality of layered portions 180 are formed spaced apart at the same distance in the device depth direction. Each layered portion 180 has a rectangular shape extending in the device depth direction as viewed from the radial direction of the light guide 140. Furthermore, the circumferential length (L1 in the figure) of the light guide 140 in the layered portion 180 is gradually increased as it goes away from the light emitting element 128 up to the central portion in the device depth direction of the light guide 140. Specifically, the respective layered portions 180 are arranged in the device depth direction, and the center lines extending in the device depth direction in the respective layered portions 180 coincide with each other.

  Further, as shown in FIG. 1, the layered portion 180 is formed to include two layers of a transmission layer 182 on the light guide 140 side and a reflection layer 184 superimposed on the transmission layer 182.

-Transmission layer 182-
The transmission layer 182 is formed of a material that has a larger refractive index of light than the material forming the light guide 140 and transmits light. Further, in the present embodiment, the material forming the transmission layer 182 is a UV curable material (resin material), and the thickness of the transmission layer 182 is, for example, 20 μm or more and 30 μm or more. It is considered as the following fixed value. Here, "a material which transmits light" is a material having a visible light transmittance of 80% or more when measured in accordance with JIS R 3106 (1998) or ISO 9050 (1990). Further, the refractive index can be measured by peeling the transmission layer 182 from the light guide 140 and using this by using a known refractive index measuring device.

  Furthermore, the transmissive layer 182 functions as a base (so-called primer) of the reflective layer 184, and improves the adhesion performance of the reflective layer 184. In addition, the transmission layer 182 is formed of, for example, a UV curing material. Thereby, the adhesion performance of the reflective layer 184 to the surface of the light guide 140 is improved as compared with the case where the transmissive layer 182 is not used.

-Reflective layer 184-
The reflective layer 184 is formed by overlapping a white reflective material (so-called white paint) whose pigment is titanium oxide on the transmissive layer 182. The reflective layer 184 is configured to reflect light, and the thickness of the reflective layer 184 is set to a defined value of, for example, 20 μm or more and 30 μm or less. The reflective layer 184 is, for example, a layer having a reflectance of 70% or more (JIS K 5602).

-Manufacturing method of light guide in which layered part 180 was formed-
Here, the manufacturing method of the light guide in which the layered part 180 was formed is demonstrated.

  First, as shown in FIG. 15, the light guide 140 is attached to the jig 510, and the light guide 140 is disposed below the ink jet recording head 512 (hereinafter referred to as "head 512"). Then, the head 512 is moved in the longitudinal direction of the light guide 140 while discharging droplets of the transmission material to be the transmission layer 182 from the head 512 toward the portion on the surface of the light guide 140 where the layered portion 180 is formed. Move it. Thus, the transmissive material is applied to the surface of the light guide 140 by the inkjet method (first application step). In the present embodiment, the outer diameter of the droplets discharged from the head 512 is, for example, 30 μm. Further, in the state immediately after the transparent material to be the transparent layer 182 is applied to the surface of the light guide 140, the surface of the transparent material is uneven.

  Next, after the surface of the transmitting material applied to the surface of the light guide 140 is made uneven as it passes along the surface of the light guide 140 by allowing 2 to 3 seconds to elapse, the transmitting material is irradiated with ultraviolet light. Then, the permeable material is cured to form the permeable layer 182 (curing process). Here, that the surface of the transmitting material is along the surface of the light guide 140 is a state where it is 5 [μm] or less according to measurement in accordance with JIS B 0681.

  Furthermore, the head 512 is moved in the longitudinal direction of the light guide 140 while discharging droplets of the reflective material to be the reflective layer 184 from the head 512 toward the transmissive layer 182 after at least the surface is cured. In this manner, the reflective material is applied by an inkjet method so as to overlap the transmissive layer 182 (second application step). Note that in the head 512, the nozzle that discharges the droplets of the reflective material is a nozzle that is different from the nozzle that discharged the droplets of the transmissive material.

(Action)
Next, the operation of the image reading apparatus 100 will be described.

  The light emitting element 128 of the light emitting device 110 emits light to the end face 140A of the light guide 140 (see FIG. 10). Thereby, the light which injected into the light guide 140 from the end surface 140A travels the inside of the light guide 140 in the longitudinal direction of the light guide 140. Then, as shown in FIG. 1, the light guide 140 emits light toward the upper side of the rod lens array 112 (in the direction of the arrow B in the drawing).

  Specifically, part of the light incident on the light guide 140 is reflected by the reflective layer 184 of the layered portion 180 and emitted upward of the rod lens array 112. In addition, the other part of the light incident on the light guide 140 is directly emitted upward of the rod lens array 112.

  Then, the rod lens array 112 is emitted from the light guide 140 and is irradiated to the document G, and guides (condenses) the reflected light reflected from the document G to the light receiving element 108. Thus, the light receiving element 108 receives the reflected light reflected from the document G and converts it into an electric signal.

-Comparison with the light emitting device 310 according to the first comparative embodiment-
Next, the operation of the light emitting device 110 will be described in comparison with the light emitting device 310 according to the first comparative embodiment. First, with respect to the configuration of the light emitting device 310, portions different from the light emitting device 110 will be mainly described.

  As shown in FIG. 18, unlike the light emitting device 110, the light emitting device 310 does not have the transmissive layer 182 formed on the light guide 140 at the portion where the layered portion 180 is formed, and only the reflective layer 184. Is formed. In other words, the reflective layer 184 is formed directly on the light guide 140.

  Therefore, as shown in FIG. 5B, the light S emitted from the light emitting element 128 enters the light guide 140 and travels to the reflection layer 184 on the surface of the light guide 140 at the incident angle α. Is reflected by the reflective layer 184 at a reflection angle α. Then, the light S is emitted from the light guide 140 toward the upper side of the rod lens array 112 (see arrow B in FIG. 1).

  On the other hand, in the light emitting device 110, as shown in FIG. 5A, the light emitting element 128 emits light, enters the light guide 140, and transmits the surface of the light guide 140 at the incident angle α. The light S traveling to the layer 182 is incident on the transmission layer 182. Here, the transmission layer 182 is formed of a material whose refractive index of light is larger than that of the light guide 140. Therefore, the light S incident from the light guide 140 to the transmission layer 182 is refracted and travels to the reflection layer 184 at the incident angle β.

  The light S that has traveled to the reflective layer 184 at the incident angle β is reflected by the reflective layer 184 at the reflective angle β. Then, the light S that has traveled to the surface of the light guide 140 at the reflection angle β is incident on the light guide 140. As described above, the transmission layer 182 is formed of a material whose refractive index of light is larger than that of the light guide 140. For this reason, the light S incident on the light guide 140 from the transmission layer 182 is refracted and travels to the inside of the light guide 140 at a reflection angle α. Then, the light S is emitted from the light guide 140 toward the upper side of the rod lens array 112 (see arrow B in FIG. 1).

  Here, assuming that the refractive index of the material forming the light guide 140 is n1 and the refractive index of the material forming the transmission layer 182 is n2, according to Snell's law, the incident angle α (reflection angle α) and the incident angle The relationship of the following equation (1) is satisfied with β (reflection angle β).

            n 1 · sin α = n 2 · sin β ... (1)

  In the present embodiment, the transmission layer 182 is formed of a material whose refractive index of light is larger than that of the light guide 140. Therefore, the incident angle β (reflection angle β) is smaller than the incident angle α (reflection angle α). Then, the amount of light reflected by the reflective layer 184 at the incident angle β is larger than the amount of light reflected by the reflective layer 184 at the incident angle α.

  That is, the amount of light reflected by the reflective layer 184 when the light emitting device 110 is used is larger than the amount of light reflected by the reflective layer 184 when the light emitting device 310 is used. In other words, when the light emitting device 110 is used, the light amount of light emitted from the light guide 140 toward the upper side of the rod lens array 112 is directed to the upper side of the rod lens array 112 when the light emitting device 310 is used. The amount of light is larger than the amount of light emitted from the light guide 140.

-Comparison with the manufacturing method of the light guide concerning the 2nd comparison form-
Next, the operation of the method for manufacturing a light guide according to the present embodiment will be described in comparison with the method for manufacturing a light guide according to the second comparative embodiment. First, regarding the method of manufacturing the light guide according to the second comparative embodiment, portions different from the method of manufacturing the light guide of the present embodiment will be mainly described.

  In the method of manufacturing the light guide according to the second comparative embodiment, the transmitting material is applied to the surface of the light guide 140 not by the inkjet method but by the screen printing method, and the reflecting material is further processed by the screen printing method. Apply so as to overlap on the permeable layer.

  In the screen printing method, the position of the screen mask when applying the transmitting material and the position of the screen mask when applying the reflecting material are dispersed. For this reason, as shown in FIG. 17A, the end of the transmission layer 182 may protrude significantly compared to the end of the reflection layer 184. In such a case, the light S incident on the end of the transmission layer 182 leaks to the outside. In addition, as shown in FIG. 17B, the end of the reflective layer 184 may protrude significantly compared to the end of the transmissive layer 182. In such a case, the portion of the reflective layer 184 that protrudes from the transmissive layer 182 may be peeled off from the surface of the light guide 140 (see the two-dot chain line in the drawing).

  On the other hand, in the method of manufacturing the light guide according to this embodiment, as described above, the transmitting material is applied to the surface of the light guide 140 by the inkjet method, and the reflecting material is further transmitted by the inkjet method. Apply to overlie. Therefore, as compared with the case of using the screen printing method, the dispersion of the position at which the transmissive material is applied and the position at which the reflective material is applied is suppressed.

  Specifically, as shown in FIG. 16, when the end of the transmission layer 182 is protruded from the end of the reflection layer 184, the amount of projection (L2 in the drawing) can be reduced. For example, the protrusion amount L2 can be set to only the outer diameter of one droplet ejected from the head 512 (see FIG. 15). In the present embodiment, since the outer diameter of the droplet is 30 μm, the protrusion amount L2 can be set to 30 μm.

(Summary)
As described above, in the light emitting device 110, the reflective layer 184 is superimposed on the transmissive layer 182. Therefore, when the light emitting device 110 is used, the amount of light emitted from the light guide 140 toward the upper side of the rod lens array 112 is guided toward the upper side of the rod lens array 112 when the light emitting device 310 is used. The amount of light is larger than the amount of light emitted from the light body 140. In other words, as compared to the case where the light emitting device 310 according to the first comparative embodiment is used, the ratio of the amount of light emitted to the object through the light guide 140 to the amount of light emitted from the light emitting element 128 (illumination ratio ) Will be higher.

  In addition, since the ratio of the light amount (illumination rate) becomes high, the light amount irradiated to the object through the light guide 140 is maintained as compared with the case of using the light emitting device 310 according to the first comparative embodiment. Thus, the amount of light emitted from the light emitting element 128 is reduced (energy saving).

  In addition, the pressing unit 160 of the housing 150 holds the light guide 140 in one place in the housing 150 by sandwiching the light guide 140 from the intersecting direction intersecting the device depth direction (one direction). . Therefore, the light guide deforms in the radial direction of the light guide when the light guide expands and contracts due to a temperature change, as compared with the case where both ends of the light guide are held by the housing. It is suppressed to

  Further, the pressing unit 160 of the housing 150 holds the light guide 140 in the housing 150 with the central portion in the device depth direction of the light guide 140 interposed therebetween. For this reason, as compared with the case where one end of the light guide is held by the housing, the amount of movement of the one end of the light guide 140 and the other end when the light guide expands and contracts due to temperature change. The difference between the movement amount of Thus, when the light emitting elements 128 are disposed at both ends of the light guide 140, the distance between one light emitting element 128 and the end face of the light guide and the other light emitting element 128 and the end face of the light guide The difference between the distance and the distance is suppressed.

  Further, in the method of manufacturing the light guide according to the present embodiment, the transmitting material and the reflecting material are applied to the surface of the light guide 140 by the inkjet method. For this reason, as described above, compared with the case where the transmitting material and the reflecting material are applied to the surface of the light guide 140 by the screen printing method, the position where the transmitting material is applied and the position where the reflecting material is applied vary. Is suppressed. As a result, the end of the reflective layer 184 largely protrudes as compared with the end of the transmissive layer 182, and peeling of the protruding portion of the reflective layer 184 from the light guide 140 is suppressed.

  Further, in the image reading apparatus 100, compared with the case where the light emitting device 310 is provided, it is possible to suppress that the reading accuracy for reading the image of the document G is lowered due to the insufficient light amount irradiated to the document G.

  Further, in the image forming apparatus 10, the decrease in the reading accuracy for reading the image of the document G is suppressed, and the decrease in the quality of the output image is suppressed as compared with the case where the light emitting device 310 is provided. Ru.

Second Embodiment
An example of a light emitting device, an image reading device, an image forming device, and a method of manufacturing a light guide according to a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, parts different from the first embodiment will be mainly described.

  In the layered portion 280 of the light emitting device 210 according to the second embodiment, the refractive index of the light of the transmitting material forming the transmitting layer 282 is larger as the distance from the light emitting element 128 to the central portion in the device depth direction of the light guide 140 It is done. Specifically, the refractive index of light of the transmitting material forming each transmitting layer 282 changes between the transmitting layers 282, and the refractive index of one transmitting layer 282 is the same.

  Here, as shown in FIG. 26, the incident angle α of the light S on the transmission layer 282 increases as the distance from the light emitting element 128 increases. That is, in the light emitting device 210, as the incident angle α of the light S on the transmission layer 282 increases, the refractive index of the light of the transmission material forming the transmission layer 282 also increases.

  Therefore, for example, when the refractive index of the light of the transmitting material forming the transmitting layer is the same at all parts, the incident angle β (see FIG. 5A) of the light S to the reflecting layer 284 is a light emitting element It becomes larger as it goes away from 128. Therefore, the amount of light reflected per unit area in the reflective layer 284 decreases as the distance from the light emitting element 128 increases. However, in the light emitting device 210, as the incident angle α of the light S on the transmission layer 282 increases, the refractive index of light of the material forming the transmission layer 282 also increases. For this reason, it is suppressed that the light quantity reflected per unit area in the reflective layer decreases as the distance from the light emitting element 128 decreases as compared with the case where the refractive index of light of the transmissive material forming the transmissive layer is the same in all parts. Be done.

  Further, as shown in FIG. 25, a plurality of layered portions 280 are arranged at intervals in the device depth direction, and the length of the plurality of layered portions 280 (transmissive layer 282) in the circumferential direction of the light guide 140 is (L3 in the figure) is the same. Here, the same means that it is within ± 10% of the average value in consideration of manufacturing variations and the like. Specifically, in the light guide 140 of the light emitting device 110, the length in the circumferential direction of the light guide 140 of the layered portion 180 (see FIG. 11) disposed closest to the light emitting element 128 is the same.

  As described above, in the light emitting device 210, the amount of light reflected per unit area in the reflective layer 284 is suppressed from decreasing as the distance from the light emitting element 128 increases. Therefore, unlike the light emitting device 110, the circumferential length of the light guide 140 of the layered portion 280 (transmissive layer 282) can be made the same.

  Further, the same length in the circumferential direction of the light guide 140 in the layered portion 280 (transmissive layer 282) makes the layered portion 280 (transmissive layer 282) as compared with the case where the lengths of the layered portion 280 are different. Defects in the shape of are easily found visually.

  It should be noted that although the invention has been described in detail with respect to particular embodiments, the invention is not limited to such embodiments, and it is possible to take on various other embodiments within the scope of the invention. It is clear to the person skilled in the art. For example, although not particularly described in the above embodiment, a correction unit that contacts the light guide 140 and corrects the posture of the light guide 140 may be formed in the housing.

  Further, in the above embodiment, the transmitting material and the reflecting material are applied to the surface of the light guide 140 by the inkjet method, but the transmitting material and the reflecting material are applied to the surface of the light guide 140 by the screen printing method, for example. It may be applied. In this case, the effect exerted by applying the transmitting material and the reflecting material to the surface of the light guide 140 by the inkjet method is not exhibited.

  In the above embodiment, the image forming apparatus transfers the image from the four color photosensitive drums to the intermediate transfer. However, for example, the image is directly transferred from the image carrier 36 of one or more colors to the sheet member P It may be an image forming apparatus.

  Further, in the first embodiment, each layered portion 180 has a rectangular shape extending in the device depth direction as viewed from the radial direction of the light guide 140, and further, the light guide in the layered portion 180 The circumferential length 140 (L1 in the figure) gradually increases as the distance from the light emitting element 128 increases to the central portion in the device depth direction of the light guide 140. However, for example, the layered portion may have a triangular shape so that the circumferential length of the light guide becomes long up to the central portion in the device depth direction of the light guide 140.

10 Image Forming Device 20 Image Forming Unit 100 Image Reading Device 102 Light Receiving Substrate 110 Light Emitting Device 112 Rod Lens Array (An Example of a Guide Member)
Reference Signs List 108 light receiving element 128 light emitting element 140 light guide 140A end surface 150 housing 182 transmission layer 184 reflection layer 210 light emitting device 280 layered portion 282 transmission layer 284 reflection layer

Claims (8)

A light guide extending in one direction,
A light emitting element disposed opposite to the end face of the light guide and irradiating the end face with light;
The surface of the light guide is interposed between a light transmission layer formed on the surface of the light guide by a material that transmits light and whose refractive index of light is larger than that of the material forming the light guide. A reflective layer formed on the light guide to reflect light toward the interior of the light guide;
A light emitting device comprising:   2. The light emitting device according to claim 1, wherein a refractive index of light of a material forming the transmission layer is increased as it goes away from the light emitting element at least to a central part of the light guide in one direction. The light guide has a cylindrical shape,
The plurality of transmission layers are arranged at intervals in the one direction,
The light emitting device according to claim 2, wherein in the plurality of transmission layers, the circumferential length of the light guide is the same. A housing for housing the light guide,
The said housing hold | maintains a part of said one direction of the said light guide in one place on both sides of the said light guide from the cross direction which cross | intersects the said one direction. The light-emitting device as described in a term.   The light emitting device according to claim 4, wherein the housing holds the light guide with a central portion in the one direction of the light guide. The light emitting device according to any one of claims 1 to 5, further comprising: a light emitting element for emitting light to an end face of the light guide and emitting light from a surface of the light guide toward an object on which an image is formed. A light emitting device as described
A plurality of light receiving elements arranged in the one direction;
A guide member for guiding light reflected from an object on which an image is formed to the light receiving element;
An image reading apparatus comprising: An image reading apparatus according to claim 6;
An image forming unit that forms an image based on image information read by the image reading apparatus;
An image forming apparatus comprising: A light transmitting material which has a refractive index of light larger than that of the material forming the light guiding material and transmits light on the surface of the light guiding material extending in one direction, the light transmitting material forming the light transmitting layer A first applying step of applying by an inkjet method,
A curing step of curing the transmission material to form a transmission layer after the surface of the transmission material applied to the surface of the light guide is along the surface of the light guide;
A second application step of applying a reflective material for forming a reflective layer on the surface of the transmissive layer at least the surface of which has been cured by an inkjet method;
The manufacturing method of the light guide in which the transmission layer which has these, and a reflection layer was formed.