JP2011075969A - Method for assembling lens array, line head, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem: when the resin layer of a lens array comes into contact with a spacer through a spherical gap material, the position of the lens array is shifted in the optical axis direction of a lens because the resin layer of the contact part is deformed, and further, positional adjustment performed while relatively moving the lens array and the spacer is difficult because friction resistance is increased. <P>SOLUTION: In an assembling method, photocurable resins 203 and 204 are injected into a metallic mold 200, glass substrates 80a and 83a are placed on the metallic mold 200, and the photocurable resins 203 and 204 are made to cure by irradiation with light from the sides of the glass substrates 80a and 83a. Thus, the resin layers 80b and 83b provided with a lens 64 in the glass substrates 80a and 83a are formed, and the spacers 81 and 82 supporting the glass substrates 80a and 83a, on which the resin layers 80b and 83b are formed, and the surfaces of the glass substrates 80a and 83a exposed by removing a portion of the resin layers 80b and 83b are joined by an adhesive 90 including the spherical gap material 91. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lens array assembling method, a line head, and an image forming apparatus.

  2. Description of the Related Art Image forming apparatuses such as copying machines and printers that use an electrophotographic system are provided with exposure means for forming an electrostatic latent image by exposing the surface of a rotating photoreceptor. As such an exposure means, a line head having a structure in which a plurality of light emitting elements such as light emitting diodes are arranged in the axial direction of a photoreceptor is known.

For example, Patent Document 1 includes a light-emitting element substrate such as glass on which a light-emitting element is formed, and a pair of lens arrays in which lenses are formed by a curved surface of a transparent resin layer. A line head for irradiating a photosensitive member through an optical unit constituted by a lens array is described. In such a line head, a spacer as a support member for supporting the lens array is provided between the light emitting element substrate and the lens array or between the pair of lens arrays in the optical axis direction of the lens. The light emitting element substrate and the pair of lens arrays are supported by the spacer so that the optical axis of the light emitting element and the optical axis of the lens coincide with each other.
In addition, as a method for manufacturing a lens array that can be used for such a line head, Patent Document 2 describes a method for obtaining a lens array by molding a resin layer having a lens on a light-transmitting substrate such as glass. Yes.
Here, in order to prevent the positions of the lens and the light emitting element formed in the lens array from deviating in a direction perpendicular to the optical axis of the lens and perform good optical writing, in Patent Document 2, positioning to the lens array is performed. A method for forming a mark and adjusting the position of a lens array in a direction orthogonal to the optical axis has been proposed.

JP 2009-98613 A JP 2008-152040 A

When adjusting the position of the lens array on the surface orthogonal to the optical axis, dust may be generated by rubbing the spacer and the resin layer of the lens array. Therefore, by sandwiching a spherical gap material between the spacer and the lens array, it is possible to adjust the lens array position in the direction perpendicular to the optical axis while avoiding the generation of dust, and through the spherical gap material. The lens array may be supported by a spacer.
However, when the resin layer of the lens array comes into contact with the spacer via the spherical gap material, the resin layer in the contacted portion is deformed. As a result, the position of the lens array is shifted in the optical axis direction of the lens. Further, since the frictional resistance is increased, it is difficult to adjust the position while relatively moving the lens array and the spacer. That is, there is a problem that the focus shift and the image forming performance are deteriorated, and good optical writing cannot be performed on the photosensitive member.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A photocurable resin is injected into a mold having a mold surface corresponding to a lens surface, a light transmissive substrate is placed on the mold, and light is irradiated from the light transmissive substrate side to perform the light curing. The resin is cured to form a resin layer having a lens on the light transmissive substrate, and a support member that supports the light transmissive substrate on which the resin layer is formed, and a part of the resin layer are removed. A method of assembling a lens array, wherein the surface of the light-transmitting substrate that is exposed is bonded with an adhesive containing a spherical gap material.

  According to this configuration, the support member and the surface of the light-transmitting substrate that is exposed by removing a part of the resin layer are joined together with an adhesive containing a spherical gap material. As a result, the surface of the light-transmitting substrate exposed by the lens array comes into contact with the spacer via the spherical gap material, and therefore it is possible to suppress the position of the lens array from being shifted in the optical axis direction of the lens. Further, since an increase in frictional resistance is suppressed, it is possible to easily adjust the position while relatively moving the lens array and the spacer.

  Application Example 2 The bonding between the support member that supports the light-transmitting substrate on which the resin layer is formed and the surface of the light-transmitting substrate that is exposed by removing a part of the resin layer is performed by using the lens. The lens array assembling method described above, wherein position adjustment is performed in a direction orthogonal to the optical axis direction of the lens, and the adhesive is cured and bonded after the position adjustment.

  According to this configuration, the lens array can be fixed by the support member at a position where the position adjustment of the lens array is performed on a plane orthogonal or substantially orthogonal to the optical axis direction of the lens.

  Application Example 3 The method for assembling the lens array, wherein the adhesive is an ultraviolet curable adhesive that is cured by irradiation with ultraviolet rays.

  According to this configuration, by adjusting the position of the lens array in a plane orthogonal or substantially orthogonal to the optical axis direction of the lens before irradiating with ultraviolet rays, the frictional resistance is low because the ultraviolet curable adhesive is not cured. The position of the lens array and the support member can be easily adjusted. Further, when the position adjustment is completed, the lens array can be immediately fixed by the support member by irradiating with ultraviolet rays.

  Application Example 4 A photocurable resin is injected into a mold having a mold surface corresponding to a lens surface, a light transmissive substrate is placed on the mold, and light is irradiated from the light transmissive substrate side to perform the photocuring. A resin layer having a lens is formed on the light transmissive substrate by curing the light transmissive resin, and a support member for supporting the light transmissive substrate on which the resin layer is formed and a part of the resin layer are removed. A lens array assembled by joining the surface of the light-transmitting substrate that is put out with an adhesive containing a spherical gap material, a light-emitting element array having a light-emitting element that emits light imaged by the lens, A line head characterized by comprising:

  According to this configuration, it is possible to prevent the focus from being deviated and the image forming performance from being deteriorated, and good optical writing on the photosensitive member cannot be performed.

  Application Example 5 A photocurable resin is injected into a mold having a mold surface corresponding to a lens surface, a light transmissive substrate is placed on the mold, and light is irradiated from the light transmissive substrate side to perform the photocuring. A resin layer having a lens is formed on the light transmissive substrate by curing the light transmissive resin, and a support member for supporting the light transmissive substrate on which the resin layer is formed and a part of the resin layer are removed. A lens array assembled by bonding the surface of the light-transmitting substrate that has been put out with an adhesive containing a spherical gap material, and a light-emitting element array having a light-emitting element that emits light imaged by the lens; An image forming apparatus comprising: a line head having a latent image; a latent image carrier on which a latent image is formed by the line head; and a developing unit that develops the latent image formed on the latent image carrier. apparatus.

  According to this configuration, it is possible to prevent the focus from being deviated and the image forming performance from being deteriorated, and good optical writing on the photosensitive member cannot be performed. For this reason, it is possible to suppress degradation in image quality to be formed.

1 is a schematic diagram illustrating an overall configuration of an image forming apparatus according to an embodiment. The perspective view of a line head. Sectional drawing which looked at the line head from the main scanning direction. The figure which shows arrangement | positioning of a some light emitting element group and a some lens. The figure which shows the junction part of a lens array and a spacer. Sectional drawing which looked at the lens array supported by the spacer as a supporting member from the main scanning direction. The flowchart of the process of joining a lens array and a spacer. (A) is sectional drawing of the lens array before performing a resin layer removal process, (b) is sectional drawing of the lens array after performing a resin layer removal process. Sectional drawing which shows that the lens array and the spacer are contacting via the adhesive mixture which mixed the gap material with the adhesive agent. The figure which shows the state provided with the lens array in the state of FIG. The figure which shows the state provided with the spacer in the state of FIG. The flowchart of the process of joining the lens array and spacer in 2nd Example. Sectional drawing which shows irradiating the ultraviolet-ray to the adhesive mixture which mixed the gap material with the ultraviolet curable adhesive. The figure for demonstrating the process of forming the lens of a lens array.

(First embodiment)
Hereinafter, the line head and the image forming apparatus according to this embodiment will be described with reference to the drawings.

  FIG. 1 is a schematic diagram illustrating the overall configuration of the image forming apparatus according to the present exemplary embodiment. The image forming apparatus 1 is an electrophotographic printer that records an image on a recording medium P through a series of image forming processes including a charging process, an exposure process, a developing process, a transfer process, and a fixing process. In this embodiment, the image forming apparatus 1 is a color printer that employs a so-called tandem method. As shown in FIG. 1, the image forming apparatus 1 includes an image forming unit 10 for a charging process, an exposure process, and a developing process, a transfer unit 20 for a transfer process, and a fixing unit for a fixing process. 30, a transport mechanism 40 for transporting a recording medium P such as paper, and a paper feed unit 50 that supplies the recording medium P to the transport mechanism 40.

  The image forming unit 10 includes an image forming station 10Y that forms a yellow toner image, an image forming station 10M that forms a magenta toner image, an image forming station 10C that forms a cyan toner image, and a black toner image. Four image forming stations including an image forming station 10K to be formed are provided.

  Each of the image forming stations 10Y, 10M, 10C, and 10K has a photosensitive drum (photosensitive member) 11 that carries an electrostatic latent image, and a charging unit 12 and a line head are provided around (outer peripheral side). An (exposure unit) 13, a developing unit 14, and a cleaning unit 15 are disposed. Since these apparatuses constituting the image forming stations 10Y, 10M, 10C, and 10K have the same configuration, only one apparatus will be described below.

  The photosensitive drum 11 has a cylindrical shape as a whole. A photosensitive layer (not shown) is formed on the outer peripheral surface (cylindrical surface) of the photosensitive drum 11 to form a light receiving surface (irradiated surface) (not shown) that receives light (emitted light) from the line head 13. ing. Further, the photosensitive drum 11 is rotatable around the axis in the direction of the arrow in FIG.

  The charging unit 12 uniformly charges the light receiving surface of the photosensitive drum 11 by corona charging or the like. The line head 13 receives image information from a host computer such as a personal computer (not shown), and emits light toward the light receiving surface of the photosensitive drum 11 in response thereto. On the other hand, the light receiving surface of the photosensitive drum 11 is uniformly charged, and a latent image corresponding to the light radiation pattern is formed.

The developing unit 14 includes a storage unit (not shown) that stores toner, and supplies and applies toner from the storage unit to the light receiving surface of the photosensitive drum 11 that carries an electrostatic latent image. Thereby, the latent image on the photosensitive drum 11 is visualized (developed) as a toner image. The cleaning unit 15 includes a rubber cleaning blade 151 that contacts the light receiving surface of the photosensitive drum 11. The cleaning blade 151 scrapes and removes toner remaining on the photosensitive drum 11 after the primary transfer described later by the cleaning blade 151.

  The transfer unit 20 transfers the toner images of the respective colors formed on the photosensitive drums 11 of the image forming stations 10Y, 10M, 10C, and 10K to the recording medium P at a time.

  In each of the image forming stations 10Y, 10C, 10M, and 10K, charging of the light receiving surface of the photosensitive drum 11 by the charging unit 12, exposure of the light receiving surface by the line head 13, and development while each photosensitive drum 11 rotates once. The toner supply to the light receiving surface by the unit 14, the primary transfer to the intermediate transfer belt 21 by pressure contact with the primary transfer roller 22, and the light receiving surface cleaning by the cleaning unit 15 are sequentially performed.

  The transfer unit 20 includes an endless belt-like intermediate transfer belt 21, and the intermediate transfer belt 21 includes a plurality of (four in the configuration illustrated in FIG. 1) primary transfer rollers 22, driving rollers 23, and driven rollers 24. The belt is stretched and is driven to rotate in the direction of the arrow shown in FIG.

  Each primary transfer roller 22 is disposed opposite to the corresponding photosensitive drum 11 via an intermediate transfer belt 21 so that a single color toner image on the photosensitive drum 11 is transferred (primary transfer) to the intermediate transfer belt 21. It has become. At the time of primary transfer, the primary transfer roller 22 is applied with a primary transfer voltage (primary transfer bias) having a polarity opposite to the charging polarity of the toner.

  On the intermediate transfer belt 21, a toner image of at least one of yellow, magenta, cyan, and black is carried. For example, when a full-color image is formed, four color toner images of yellow, magenta, cyan, and black are sequentially transferred onto the intermediate transfer belt 21 to form a full-color toner image as an intermediate transfer image.

  The transfer unit 20 includes a secondary transfer roller 25 disposed opposite to the driving roller 23 via the intermediate transfer belt 21 and a cleaning unit 26 disposed opposite to the driven roller 24 via the intermediate transfer belt 21. is doing.

  The secondary transfer roller 25 transfers a single-color or full-color toner image (intermediate transfer image) formed on the intermediate transfer belt 21 to a recording medium P such as paper, film, or cloth supplied from the paper supply unit 50. (Secondary transfer). The secondary transfer roller 25 is pressed against the intermediate transfer belt 21 and applied with a secondary transfer voltage (secondary transfer bias) during secondary transfer. During such secondary transfer, the drive roller 23 also functions as a backup roller for the secondary transfer roller 25.

  The cleaning unit 26 has a rubber cleaning blade 261 that contacts the surface of the intermediate transfer belt 21, and the toner remaining on the intermediate transfer belt 21 after the secondary transfer is scraped off and removed by the cleaning blade 261. It has become.

  The fixing unit 30 includes a fixing roller 301 and a pressure roller 302 that is pressed against the fixing roller 301, and is configured such that the recording medium P passes between the fixing roller 301 and the pressure roller 302. Yes. Further, the fixing roller 301 has a built-in heater for heating the outer peripheral surface of the fixing roller, and can heat and press the recording medium P passing therethrough. The fixing unit 30 having such a configuration heats and presses the recording medium P that has received the secondary transfer of the toner image, and fuses the toner image to the recording medium P to fix it as a permanent image.

  The conveyance mechanism 40 includes a registration roller pair 41 that conveys the recording medium P while feeding the recording medium P to the secondary transfer portion between the secondary transfer roller 25 and the intermediate transfer belt 21 described above, and fixing by the fixing unit 30. It has conveyance roller pairs 42, 43, and 44 for nipping and conveying the processed recording medium P.

  When such a transport mechanism 40 forms an image on only one surface of the recording medium P, the recording medium P fixed on one surface by the fixing unit 30 is nipped and transported by the transport roller pair 42. Then, it is discharged outside the image forming apparatus 1. When forming an image on both surfaces of the recording medium P, the recording medium P fixed on one surface by the fixing unit 30 is once sandwiched by the conveying roller pair 42 and then the conveying roller pair 42 is driven to reverse. Then, the conveyance roller pairs 43 and 44 are driven to invert the recording medium P and return to the registration roller pair 41, and an image is formed on the other surface of the recording medium P by the same operation as described above.

  The paper feed unit 50 includes a paper feed cassette 51 that stores unused recording media P, and a pickup roller 52 that feeds the recording media P from the paper feed cassette 51 one by one toward the registration roller pair 41. .

Next, the line head 13 will be described. FIG. 2 is a perspective view of the line head 13. 3 is a cross-sectional view taken along line AA when the line head 13 of FIG. 2 is viewed from the arrow direction in the main scanning direction D1. As shown in FIG. 3, the line head 13 is disposed to face the light receiving surface 111 of the photosensitive drum 11. Further, the line head 13 is disposed so that the main scanning direction D1 is parallel to the rotation axis of the photosensitive drum 11.

  The lens array 80 and the lens array 83 are provided with the longitudinal direction set as the main scanning direction D1 across the spacers 81 and 82 as support members for supporting the lens arrays 80 and 83. Further, the lens array 83 and the light emitting element substrate 87 are provided with the longitudinal direction set as the main scanning direction D1 across the spacers 84 and 85 as support members for supporting the lens array 83.

  The light shielding member 86 is provided between the light emitting element substrate 87 and the lens array 83 with the longitudinal direction as the main scanning direction D1. The light emitting element substrate 87 is formed of a transparent substrate such as glass or resin, and is provided in a housing member 88 fixed to the base 89.

  On the light emitting element substrate 87 side of the lens array 80 and the lens array 83, a plurality of lenses 64 each having a convex curved surface are formed. The constituent material of the lens 64 is not particularly limited as long as it has optical characteristics. For example, a resin material and / or a glass material is preferably used.

  On the base 89 side of the light emitting element substrate 87, for example, a light emitting element group 71 such as an organic EL (Organic Electroluminescence), a light emitting diode or the like is provided. The light emitting element group 71 is accommodated in the space area of the recess 881 formed in the accommodating member 88. A light emitting element array is configured by the light emitting element substrate 87 and the light emitting element group 71 provided on the light emitting element substrate 87.

  The concave portion 881 accommodates conductors (not shown) electrically connected to the light emitting elements (not shown) constituting the light emitting element group 71 or a circuit (not shown) for driving each light emitting element. ing.

  The light L emitted from the light emitting element group 71 in the optical axis direction D3 includes the light emitting element substrate 87, the through holes 861 formed in the light shielding member 86, the lenses 64 formed in the lens array 83, the spacer 81, and the spacer 82. The light passes through the space area formed between them and the lens 64 formed in the lens array 80, and is irradiated onto the light receiving surface 111 of the photosensitive drum 11.

  FIG. 4 is a view as seen from the optical axis direction D3 and shows the arrangement of the plurality of light emitting element groups 71 in the light emitting element substrate 87 and the plurality of lenses 64 in the lens arrays 80 and 83. As shown in FIG. 4, the lenses 64 are arranged in a plurality of rows in the main scanning direction D1, and are arranged in a plurality of rows in the sub-scanning direction D2 orthogonal to the main scanning direction D1.

  The plurality of lenses 64 are arranged in a matrix of 3 rows and n columns (n is an integer of 2 or more) spaced apart from each other. As shown in FIG. 3, one lens 64 formed on the lens array 80 and one lens 64 formed on the lens array 83 are arranged to face each other so that their optical axes coincide.

  As shown in FIG. 4, the plurality of light emitting element groups 71 are spaced apart from each other and arranged in a matrix of 3 rows and n columns (n is an integer of 2 or more) corresponding to the plurality of lenses 64. Each light emitting element group 71 includes a plurality (eight in this embodiment) of light emitting elements 74.

  The eight light emitting elements 74 constituting each light emitting element group 71 are arranged along the surface of the light emitting element substrate 87 on the base 89 side. The light L in FIG. 3 emitted from each light emitting element 74 passes through a pair of lenses 64 and is collected on the light receiving surface 111 of the photosensitive drum 11.

  As shown in FIG. 4, the eight light emitting elements 74 are spaced apart from each other, arranged in four columns in the main scanning direction D1, and arranged in two rows in the sub-scanning direction D2. As described above, the eight light emitting elements 74 are arranged in a matrix of 2 rows and 4 columns. Two adjacent light emitting elements 74 belonging to one row (light emitting element row) are arranged so as to be shifted in the main scanning direction D1. In the eight light emitting elements 74 having a matrix of 2 rows and 4 columns in this way, the light emitting elements 74 adjacent in the main scanning direction D1 are complemented by one light emitting element 74 in the next row. .

  FIG. 5 is an enlarged view of the portion B in FIG. 2, and shows a joint portion between the lens array 80 and the spacer 82. FIG. 6 is a cross-sectional view of the lens arrays 80 and 83 supported by the spacers 81 and 82 as support members when viewed from the main scanning direction D1.

  The lens array 80 according to the present embodiment includes a glass substrate 80a formed of glass as a light transmissive substrate and a resin layer 80b formed of resin. The resin layer 80b is formed in a range C2 that is a central portion in the sub-scanning direction D2 of the lens array 80, and is not formed in a range C1 that is an end portion in the sub-scanning direction D2. When the lens array 80 is viewed from the side of the spacers 81 and 82 (lower side in the drawing), the glass substrate 80a in the range C2 is covered with the resin layer 80b, but the glass substrate 80a in the range C1 is exposed.

  The lens 64 is configured by a convex curved surface S1 formed in the resin layer 80b. The lens array 80 includes a lens forming portion 802 in which a lens 64 is formed in a range C2 in the sub-scanning direction D2, and an end portion 801 in which a flat surface S2 orthogonal to the optical axis direction D3 is formed in the range C1 in the sub-scanning direction D2. It consists of. The end 801 in FIG. 6 is formed at the end of the lens array 80 in the sub-scanning direction D2.

  Similarly, the lens array 83 includes a glass substrate 83a formed of glass as a light transmissive substrate and a resin layer 83b formed of resin. The resin layer 83b is formed in a range C2 that is a central portion in the sub-scanning direction D2 of the lens array 83, and is not formed in a range C1 that is an end portion in the sub-scanning direction D2. Therefore, when the lens array 83 is viewed from the opposite side (lower side of the drawing) of the spacers 81 and 82, the glass substrate 83a is covered with the resin layer 83b in the range C2, but the glass substrate 83a is covered in the range C1. Exposed.

  The lens 64 is configured by a convex curved surface S1 formed in the resin layer 83b. The lens array 83 has a lens forming portion 832 in which a lens 64 is formed in a range C2 in the sub-scanning direction D2, and an end portion 831 in which a flat surface S2 orthogonal to the optical axis direction D3 is formed in the range C1 in the sub-scanning direction D2. It consists of. The end 831 in FIG. 6 is formed at the end of the lens array 83 in the sub-scanning direction D2.

  The spacers 81 and 82 regulate the distance between the lens array 80 and the lens array 83 in the optical axis direction D3. The length of the flat surface S2 formed in the range C1 in the sub-scanning direction D2 is longer than the length M1 of the flat surface S3 formed in the spacers 81 and 82 in the sub-scanning direction D2. Therefore, the relative position between the lens array 80 and the spacers 81 and 82 can be adjusted.

  As shown in FIGS. 5 and 6, the lens array 80 and the spacers 81 and 82 are bonded together by an adhesive mixture between the flat surface S2 of the lens array 80 and the flat surface S3 of the spacers 81 and 82. . The adhesive mixture is a mixture of the adhesive 90 and the gap material 91.

  The adhesive mixture in which the gap material 91 is mixed with the adhesive 90 is also present between the flat surface S4 on the lens array 83 side in the spacers 81 and 82 and the flat surface S5 on the spacer 81 and 82 side in the lens array 83 in FIG. An agent is provided, and the lens array 83 and the spacers 81 and 82 are joined.

  The lens 64 formed on the lens array 83 at a position facing the lens 64 formed on the lens array 80 is provided so that the optical axis E coincides.

  Next, a method for joining the lens array 80 and the spacers 81 and 82 will be described. FIG. 7 is a flowchart of a process of joining the lens array 80 and the spacers 81 and 82.

  FIG. 8A is a cross-sectional view of the lens arrays 80 and 83 before the resin layer removing step is viewed from the main scanning direction D1. Here, a method of forming the lenses 64 of the lens arrays 80 and 83 will be described. FIGS. 14A and 14B are views for explaining a process of forming the lenses 64 of the lens arrays 80 and 83. FIG. In the present embodiment, the lens arrays 80 and 83 are formed using molds having the same shape.

  First, in step (a), a mold 200 corresponding to the lens surfaces of the lenses 64 of the lens arrays 80 and 83 is prepared. The curved surface mold part 201 corresponding to the concave mold of the lens surface in the mold 200 is formed by machining. The depth of the curved mold 201 is usually 100 to 200 μm and the diameter is about 0.1 to 1 mm. Instead of forming the curved mold 201 by machining, it can also be formed by etching. Alternatively, it can also be formed by a method in which a large number of beads having a surface shape corresponding to the convex surface of the lens 64 are arranged and transferred to a mold substrate. The dispenser 202 capable of measuring and injecting the amount of liquid into the curved surface mold portion 201 of the mold 200 formed in this way is sequentially injected with an amount of the photocurable resin 203 that fills the curved surface mold portion 201 halfway. When the injection is performed while raising the dispenser 202 as shown by an arrow, the photocurable resin 203 can be prevented from being disturbed.

  Next, in the step (b), in a state where the photocurable resin 203 is injected into all the curved mold parts 201, the ultraviolet ray 206 from the UV (ultraviolet) lamp 205 is irradiated from above, and the photocurable resin 203 is applied. Make it semi-cured. Here, the reason why the photocurable resin 203 is not completely cured is to prevent the occurrence of an interface with the photocurable resin 204 to be additionally injected in the next step (c).

  Next, in the step (d), the elongated rectangular glass substrates 80a and 83a having the same shape as the glass substrates 80a and 83a in the lens arrays 80 and 83 are respectively formed on the curved surface portions 201 of the photocurable resins 203 and 204. And press at a constant pressure on the mold 200 which is filled a little extra. At this time, a gap member 207 that keeps a predetermined small distance around the entire curved surface mold portion 201 is disposed. By disposing the gap material 207, excess photo-curable resin 204 and air bubbles can be easily removed. In this state, ultraviolet rays 206 from the UV lamp 205 are irradiated from above through the glass substrates 80a and 83a to completely cure the photocurable resins 203 and 204.

  After the photocurable resins 203 and 204 are completely cured to become the lens 64, the lens arrays 80 and 83 are obtained by removing the glass substrates 80a and 83a from the mold 200 together with the lens 64 in the step (e). It is done.

  Thus, in the lens 64, the photocurable resins 203 and 204 are injected into the mold 200 having the curved surface mold portion 201 which is a mold surface having a concave surface corresponding to the convex surface of the lens 64, and the mold 200 is made of glass. It is formed by resin layers 80b and 83b on which the substrates 80a and 83a are placed and the photocurable resins 203 and 204 are cured by irradiating light from the glass substrates 80a and 83 side.

  FIG. 8B is a cross-sectional view of the lens arrays 80 and 83 after the resin layer removing step is viewed from the main scanning direction D1. In the resin layer removing step S100 in FIG. 7, the resin layer in the range C1 indicated by the broken lines of the lens arrays 80 and 83 in FIG. 8B is removed with a metal blade such as iron. Since the glass substrate 80a is harder than iron, it is not damaged when removed with a blade. Alternatively, a method may be used in which the region C2 in FIG.

  In the coating step S110 of FIG. 7, an adhesive mixture in which the gap material 91 is mixed with the adhesive 90 is prepared. Then, an adhesive mixture is applied to the flat surface S2 of the lens array 80 or the flat surface S3 of the spacers 81 and 82.

  FIG. 9 is a cross-sectional view seen from the main scanning direction D1 showing that the lens array 80 and the spacers 81 and 82 are in contact with each other through an adhesive mixture in which the gap material 91 is mixed with the adhesive 90. In the contact step S <b> 120, the lens array 80 is placed on a table 1000 having a flat surface with the lens 64 facing away from the table 1000. Then, the flat surfaces S3 of the spacers 81 and 82 are brought into contact with the flat surface S2 formed on the end portion 801 of the lens array 80 via an adhesive mixture.

  In the position adjustment step S130, the relative positions of the lens array 80 and the spacers 81 and 82 in the direction orthogonal or substantially orthogonal to the optical axis direction D3 are adjusted. That is, the relative positions of the lens array 80 and the spacers 81 and 82 in the main scanning direction D1 and the sub-scanning direction D2 are adjusted. In this embodiment, the spacers 81 and 82 are moved with respect to the lens array 80 fixed to the table 1000.

  After the position adjustment step S130 is performed, the adhesive 90 is cured, and the lens array 80 and the spacers 81 and 82 are joined.

  The flat surface S2 of the lens array 80 is wider than the flat surface S3 of the spacers 81 and 82. Therefore, the main scanning direction D1 and the sub-scanning direction D2 are made while the flat surfaces S3 of the spacers 81 and 82 are brought into contact with the flat surface S2 of the lens array 80 through an adhesive mixture in which the gap material 91 is mixed with the adhesive 90. Can be moved to. As a result, the relative positions of the spacers 81 and 82 and the lens array 80 on a plane orthogonal or substantially orthogonal to the optical axis direction D3 can be adjusted.

  As described above, the lens array 80 and the spacers 81 and 82 can be joined by the steps described above.

  FIG. 10 is a diagram showing a state in which a lens array 83 is further provided in the state of FIG. The lens array 83 is obtained by removing the resin layer in the range C1 in the resin layer removing step S100. An adhesive mixture in which the gap material 91 is mixed with the adhesive 90 is applied to the flat surface S4 of the spacers 81 and 82 or the flat surface S5 of the lens array 83, and the lens array 83 is brought into contact with the spacers 81 and 82. Then, position adjustment is performed in a plane orthogonal or substantially orthogonal to the optical axis direction D3 between the spacers 81 and 82 and the lens array 83, that is, in the main scanning direction D1 and the sub-scanning direction D2.

  After the position adjustment is performed, the adhesive 90 is cured, and the lens array 83 and the spacers 81 and 82 are joined.

  FIG. 11 is a view showing a state in which spacers 84 and 85 are further provided in the state of FIG. Spacers 84 and 85 are joined to the lens array 83 by the same method as the coating step S110 to the position adjustment step S130 in the flowchart shown in FIG.

  An adhesive mixture in which the gap material 91 is mixed with the adhesive 90 is applied to the flat surface S6 of the spacers 84 and 85 or the flat surface S2 of the end 831 of the lens array 83 (application step S110), and the flat surface S2 is flattened. S5 is brought into contact (contact step S120).

  Then, position adjustment is performed in a plane orthogonal to or substantially orthogonal to the optical axis direction D3 between the spacers 84 and 85 and the lens array 83, that is, in the main scanning direction D1 and the sub-scanning direction D2 (position adjustment step S130).

  After the position adjustment step S130 is performed, the adhesive 90 is cured, and the lens array 83 and the spacers 84 and 85 are joined.

  As described above, in the method of assembling the line head 13 in the present embodiment described above, the photocurable resins 203 and 204 are injected into the mold 200 having the curved surface mold portion 201 which is the mold surface corresponding to the lens surface of the lens 64. Glass substrates 80a and 83a as light transmissive substrates are placed on the mold 200, and light curable resins 203 and 204 are cured by irradiating light from the glass substrates 80a and 83a side, and the lenses 64 are provided on the glass substrates 80a and 83a. The resin layers 80b and 83b are formed, spacers 81 and 82 as support members for supporting the glass substrates 80a and 83a on which the resin layers 80b and 83b are formed, and a part of the resin layers 80b and 83b are removed and exposed. The surfaces of the glass substrates 80a and 83a are bonded with an adhesive 90 including a spherical gap material 91.

  According to this configuration, the surfaces of the glass substrates 80a and 83a exposed from the lens arrays 80 and 83 are in contact with the spacers 81 and 82 via the spherical gap material 91, so that the positions of the lens arrays 80 and 83 are the lenses 64. Can be suppressed from shifting in the optical axis direction D3. Further, since the increase in frictional resistance is suppressed, the position adjustment performed while relatively moving the lens arrays 80 and 83 and the spacers 81 and 82 can be easily performed.

  Also, the spacers 81 and 82 that support the glass substrates 80a and 83a on which the resin layers 80b and 83b are formed and the surfaces 80b and 83b that are exposed by removing a part of the resin layers 80b and 83b are bonded to the lens. The position is adjusted in a direction orthogonal to the optical axis direction of 64, and after the position adjustment, the adhesive 90 is cured and joined.

  According to this configuration, the lens arrays 80 and 83 are fixed by the spacers 81, 82, 84, and 85 at positions where the position adjustment of the lens arrays 80 and 83 is performed on a plane orthogonal or substantially orthogonal to the optical axis direction of the lens. be able to.

(Second embodiment)
In the second embodiment, the lens arrays 80 and 83 and the spacers 81, 82, 84, and 85 are joined using an ultraviolet curable adhesive that cures when irradiated with ultraviolet rays. FIG. 12 is a flowchart of a process of joining the lens array 80 and the spacers 81 and 82 in the second embodiment. FIG. 12 is obtained by adding an ultraviolet irradiation step S140 to the flowchart of FIG.

  The resin layer removing step S100, the coating step S110, the contact step S120, and the position adjusting step S130 in the second example are the same as the method described in the first example.

  FIG. 13 is a cross-sectional view showing that the adhesive mixture in which the gap material 91 is mixed with the ultraviolet curable adhesive 90a is irradiated with ultraviolet rays. FIG. 13 is a cross-sectional view depicting arrows indicating that the ultraviolet rays are irradiated on the cross-sectional view of FIG. 9.

  In the ultraviolet irradiation step S140, ultraviolet rays are irradiated from the direction of the arrow in FIG. Since the spacers 81a and 82a of the second embodiment are light transmissive, the ultraviolet rays are transmitted through the spacers 81a and 82a and irradiated with an adhesive mixture in which the gap material 91 is mixed with the ultraviolet curable adhesive 90a. Then, the ultraviolet curable adhesive 90a is cured, and the lens array 80 and the spacers 81a and 82a are joined.

  Similarly, the lens array 83 and the spacers 84 and 85 are joined using an adhesive mixture in which the gap material 91 is mixed with the ultraviolet curable adhesive 90a.

  According to the method of this embodiment, the ultraviolet curable adhesive 90a is cured by adjusting the position of the lens arrays 80 and 83 in a plane orthogonal or substantially orthogonal to the optical axis direction of the lens 64 before irradiating the ultraviolet rays. Since the frictional resistance is small before this, the position adjustment between the lens array 80 and the spacers 81a and 82a and the lens array 83 and the spacers 84 and 85 becomes easy. Further, when the position adjustment is completed, the lens array 80 and the spacers 81a and 82a, and the lens array 83 and the spacers 84 and 85 can be fixed immediately by irradiating with ultraviolet rays.

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 11 ... Photosensitive drum (photosensitive body), 13 ... Line head, 14 ... Developing part, 64 ... Lens, 71 ... Light emitting element group, 80, 83 ... Lens array, 80a, 83a ... Glass substrate, 80b 83b ... Resin layer, 81, 82, 84, 85 ... Spacer, 87 ... Light emitting element substrate, 90 ... Adhesive, 90a ... UV curable adhesive, 91 ... Gap material, 201 ... Curved surface part, 203, 204 ... Photo-curing resin, D3: optical axis direction.

Claims (5)

Injecting a photocurable resin into a mold with a mold surface corresponding to the lens surface,
A light transmissive substrate is placed on the mold, light is irradiated from the light transmissive substrate side to cure the photocurable resin, and a resin layer having a lens is formed on the light transmissive substrate.
A support member that supports the light-transmitting substrate on which the resin layer is formed, and a surface of the light-transmitting substrate that is exposed by removing a part of the resin layer are bonded with an adhesive including a spherical gap material. A method of assembling a lens array, characterized by joining.   The bonding between the support member that supports the light-transmitting substrate on which the resin layer is formed and the surface of the light-transmitting substrate that is exposed by removing a part of the resin layer is the optical axis direction of the lens. The lens array assembling method according to claim 1, wherein position adjustment is performed in an orthogonal direction, and the adhesive is cured and bonded after the position adjustment.   The lens array assembling method according to claim 1, wherein the adhesive is an ultraviolet curable adhesive that is cured by irradiation with ultraviolet rays. A photocurable resin is injected into a mold having a mold surface corresponding to the lens surface, a light transmissive substrate is placed on the mold, and light is irradiated from the light transmissive substrate side to cure the photocurable resin. Forming a resin layer having a lens on the light-transmitting substrate, removing the support layer supporting the light-transmitting substrate on which the resin layer is formed, and a part of the resin layer, and exposing the light A lens array assembled by bonding the surface of the conductive substrate with an adhesive containing a spherical gap material;
A light emitting element array having a light emitting element that emits light imaged by the lens;
A line head characterized by comprising: A photocurable resin is injected into a mold having a mold surface corresponding to the lens surface, a light transmissive substrate is placed on the mold, and light is irradiated from the light transmissive substrate side to cure the photocurable resin. Forming a resin layer having a lens on the light-transmitting substrate, removing the support layer supporting the light-transmitting substrate on which the resin layer is formed, and a part of the resin layer, and exposing the light A line head having a lens array assembled by bonding a surface of a conductive substrate with an adhesive containing a spherical gap material, and a light emitting element array having a light emitting element that emits light imaged by the lens; ,
A latent image carrier on which a latent image is formed by the line head;
A developing unit for developing the latent image formed on the latent image carrier;
An image forming apparatus comprising:

Images