JP2013022837A - Exposure device, image forming apparatus, and method of manufacturing exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To press a substrate having a plurality of light emitting elements arranged against a substrate contact surface of a support member.SOLUTION: An LED head 15Bk includes a substrate 31 which has a plurality of light emitting elements arranged on a lower surface 31a along a length, a lens array holder 34 which supports the substrate 31 on a substrate contact surface S1, and an elastically deformable plate-like base 35 for pressing the substrate 31 against the substrate contact surface S1. The base 35 has a pair of bent parts 4, 5 which are bent or curved to be concave to the side of the substrate 31 at positions corresponding to both lengthwise ends of the substrate 31, and is configured to be installed while engaging the lens array holder 34 to elastically deform in a direction orthogonal to an upper surface 31b of the substrate 31 and pressing both the lengthwise ends of the substrate 31 with the bent parts 4, 5 with its elastic restoring force.

Description

  The present invention relates to an exposure apparatus, an image forming apparatus, and a method for manufacturing the exposure apparatus.

  In an electrophotographic image forming apparatus (for example, a printer, a copying machine, a facsimile machine, a multifunction machine, etc.), an exposure apparatus (for example, an LED head) that forms an electrostatic latent image by irradiating a charged photosensitive member with light. Used.

  The exposure apparatus includes, for example, a substrate on which an LED array is mounted, a rod lens array disposed so as to face the LED array, and a lens array holder that supports the substrate and the rod lens array (for example, Patent Document 1). See). In this exposure apparatus, the light emitted from the LED array passes through the rod lens array and is converged, and is irradiated onto the surface of the photoconductor disposed at the imaging position of the rod lens array, thereby forming an electrostatic latent image. Is done.

  In Patent Document 1, as a technique for assembling the substrate to the lens array holder, a base (pressing member) for placing the substrate on the substrate contact surface formed on the lens array holder and pressing the substrate against the substrate contact surface Has been disclosed which is assembled on a substrate. In the technique described in Patent Document 1, the base is provided with protrusions projecting outward in the width direction at a plurality of positions in the length direction on both edges in the width direction. In addition, slits are formed inward in the width direction of the protrusions of the base, and thin bridge portions are formed on both sides of the protrusions of the base. The distance between the protrusions on both edges in the width direction of the base is larger than the distance between the inner walls of the lens array holder. On the other hand, on the inner wall of the lens array holder, a groove having a shape corresponding to the protrusion is formed at a position corresponding to each protrusion of the base. When the base is assembled, the base is inserted downward into the lens array holder toward the substrate. At this time, the protruding portion of the base is pressed against the inner wall of the lens array holder and is displaced inward by the bending of the bridge portion. After the base comes into contact with the substrate, the protrusion is pushed down further. As a result, the bridge portion bends downward, and subsequently the protrusion portion enters the groove by the urging force of the bridge portion, and the protrusion portion is locked to the groove in a state where the bridge portion is bent downward. When the bridge portion attempts to return to the original shape, the base generates a pressing force that presses the substrate against the substrate contact surface.

JP 2009-298155 A

  In the above conventional technique, the configuration for pressing the substrate on which the plurality of light emitting elements are arranged against the substrate contact surface of the support member is complicated.

  An object of the present invention is to provide an exposure apparatus, an image forming apparatus, and a method of manufacturing an exposure apparatus that can press a substrate on which a plurality of light-emitting elements are arranged to a substrate contact surface of a support member with a simple configuration. To do.

  An exposure apparatus according to the present invention is a substrate having a first surface and a second surface opposite to the first surface, and a plurality of light emitting elements are arranged on the first surface along a longitudinal direction thereof. A substrate, a substrate contact surface that contacts the first surface of the substrate, a support member that supports the substrate on the substrate contact surface, and a length of the substrate on the second surface of the substrate An elastically deformable plate-like pressing member that is installed along a direction and presses the substrate against the substrate contact surface, and protrudes toward the substrate side at positions corresponding to both longitudinal ends of the substrate. A pressing member having a pair of bent portions bent or curved so that the pressing member is elastically deformed in a direction perpendicular to the second surface of the substrate by engaging with the support member, The both ends in the longitudinal direction of the substrate are pressed by the pair of bent portions by elastic restoring force. Characterized in that it is configured to be placed in a state.

  An image forming apparatus according to the present invention includes an electrostatic latent image carrier and an exposure device that forms an electrostatic latent image by irradiating the electrostatic latent image carrier with light. A substrate having a first surface and a second surface opposite to the first surface, wherein a plurality of light emitting elements are disposed on the first surface along a longitudinal direction of the substrate, and a first of the substrate A substrate abutting surface that abuts the surface, a support member that supports the substrate on the substrate abutting surface, and a second surface of the substrate that is disposed along the longitudinal direction of the substrate, the substrate A pair of elastically deformable plate-like pressing members for pressing the substrate against the substrate contact surface, wherein the pair of members are bent or curved so as to protrude toward the substrate at positions corresponding to both ends in the longitudinal direction of the substrate. A pressing member having a bent portion, and the pressing member engages with the support member to thereby Elastically deformed in a direction perpendicular to the second surface, characterized in that it is configured to be placed in a state of pressing the longitudinal end portions of the substrate with the pair of bent portions due to its elastic restoring force.

  An exposure apparatus manufacturing method according to the present invention is a substrate having a first surface and a second surface opposite to the first surface, and a plurality of light-emitting elements are formed on the first surface along a longitudinal direction thereof. Providing an assembly comprising: a substrate disposed; and a substrate abutting surface that abuts a first surface of the substrate, and a support member that supports the substrate on the substrate abutting surface; A pair of elastically deformable plate-shaped pressing members for pressing a substrate against the substrate contact surface, which are bent or curved so as to protrude toward the substrate at positions corresponding to both ends in the longitudinal direction of the substrate And a step of installing the pressing member having the bent portion on the second surface of the substrate along the longitudinal direction of the substrate, and in the installing step, the one end portion in the longitudinal direction of the pressing member A surface provided on the one side of the support member is a surface facing away from the substrate side. After the abutment of the pressing member, the pair of bent portions are pressed against the second surface of the substrate, and the pressing member is elastically deformed in a direction perpendicular to the second surface of the substrate. A surface of the other end portion in the longitudinal direction facing the side opposite to the substrate side is brought into contact with a pressing portion provided on the other side of the support member.

  According to the present invention, a substrate on which a plurality of light emitting elements are arranged can be pressed against the substrate contact surface of the support member with a simple configuration.

1 is a schematic diagram showing a configuration of an image forming apparatus having an exposure apparatus in Embodiment 1. FIG. FIG. 3 is a transverse sectional view showing the LED head and the photosensitive drum in the first embodiment. 2 is a longitudinal sectional view showing an LED head and a photosensitive drum in Embodiment 1. FIG. FIG. 3 is a diagram showing a configuration of a base, a substrate, and a lens array holder in the first embodiment. FIG. 5 is a diagram for explaining a manufacturing procedure of the LED head in the first embodiment. FIG. 6 is a cross-sectional view showing an LED head and a photosensitive drum in a second embodiment. FIG. 10 is a diagram illustrating a configuration of a base in a second embodiment. FIG. 10 is a diagram for explaining a manufacturing procedure of the LED head in the second embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
[Configuration of Image Forming Apparatus]
FIG. 1 is a schematic diagram showing a configuration of an image forming apparatus 11 having an exposure apparatus (exposure unit) in the present embodiment. The image forming apparatus 11 is an apparatus that forms an image using an exposure apparatus. Specifically, the image forming apparatus 11 is an electrophotographic printing apparatus, which forms an electrostatic latent image by irradiating light onto an electrostatic latent image carrier with an exposure device, and develops the electrostatic latent image. By developing with an agent, an image is formed on the recording medium.

  In the example of FIG. 1, the image forming apparatus 11 is an electrophotographic color printer, and includes image forming units 12Bk, 12Y, 12M, and 12C that are image forming units that form images of black, yellow, magenta, and cyan. . The image forming units 12Bk, 12Y, 12M, and 12C are arranged along a conveyance path of a sheet as a recording medium. In addition to paper, OHP sheets, envelopes, copy paper, special paper, and the like can be used as the recording medium.

  The image forming units 12Bk, 12Y, 12M, and 12C uniformly distribute the surfaces of the photosensitive drums 13Bk, 13Y, 13M, and 13C as electrostatic latent image carriers and the photosensitive drums 13Bk, 13Y, 13M, and 13C, respectively. A charging roller 14Bk, 14Y, 14M, 14C as a charging device for charging, and a toner (not shown) as a developer are attached to the electrostatic latent images formed on the surfaces of the photosensitive drums 13Bk, 13Y, 13M, 13C. Developing rollers 16Bk, 16Y, 16M, and 16C are provided as developer carrying members that form toner images of respective colors that are visible images. The image forming units 12Bk, 12Y, 12M, and 12C respectively include toner supply rollers 18Bk, 18Y, 18M, and 18C as developer supply members, developing blades 19Bk, 19Y, 19M, and 19C, and toner that contains toner. And cartridges 20Bk, 20Y, 20M, and 20C. The toner supply rollers 18Bk, 18Y, 18M, and 18C are disposed so as to be in pressure contact with the developing rollers 16Bk, 16Y, 16M, and 16C, respectively, and the toner supplied from the toner cartridges 20Bk, 20Y, 20M, and 20C is supplied to the developing rollers 16Bk, 20M, and 20C, respectively. 16Y, 16M, and 16C are supplied. The developing blades 19Bk, 19Y, 19M, and 19C are disposed so as to be in pressure contact with the developing rollers 16Bk, 16Y, 16M, and 16C, respectively, and the toner supply rollers 18Bk, 18Y, and 18M are provided on the developing rollers 16Bk, 16Y, 16M, and 16C, respectively. , 18C, the toner is thinned.

  Above the photosensitive drums 13Bk, 13Y, 13M, and 13C in the image forming units 12Bk, 12Y, 12M, and 12C, LED heads 15Bk, 15Y, 15M, and 15C as exposure devices are provided on the photosensitive drums 13Bk, 13Y, 13M, and 13C, respectively. It is arranged at a position facing 13C. The LED heads 15Bk, 15Y, 15M, and 15C are devices that form an electrostatic latent image by exposing the photosensitive drums 13Bk, 13Y, 13M, and 13C according to the image data of each color, respectively.

  A transfer unit is disposed below the photosensitive drums 13Bk, 13Y, 13M, and 13C in the image forming units 12Bk, 12Y, 12M, and 12C. The transfer unit includes transfer rollers 17Bk, 17Y, 17M, and 17C serving as transfer devices, and a transport belt 21 serving as a transport member that transports paper and is disposed so as to be able to run in the direction of arrow e in FIG. . The transfer rollers 17Bk, 17Y, 17M, and 17C are arranged to face the photosensitive drums 13Bk, 13Y, 13M, and 13C via the conveyance belt 21, respectively, and charge the paper to a polarity opposite to that of the toner, so that each color toner Transfer the image to the paper.

  A paper feed mechanism for supplying paper to the transport belt 21 is disposed below the image forming apparatus 11. The paper feed mechanism includes a hopping roller 22, a registration roller 23, a paper storage cassette 24 as a medium storage unit, and a paper color measurement unit 25 that measures the color of the paper in the paper storage cassette 24. Further, a fixing device 28 is provided on the discharge side of the conveyor belt 21. The fixing device 28 includes a heating roller and a backup roller, and is a device that fixes the toner transferred onto the paper by pressurizing and heating. A discharge roller and a pinch roller (not shown) and a paper stacker 29 are provided on the discharge side of the fixing device 28.

[Operation of Image Forming Apparatus]
Next, the operation of the image forming apparatus 11 will be described.
The paper in the paper storage cassette 24 is fed out by the hopping roller 22 and sent to the registration roller 23. Subsequently, the sheet is sent from the registration roller 23 to the conveyance belt 21 and is sequentially conveyed to the image forming units 12Bk, 12Y, 12M, and 12C as the conveyance belt 21 travels.

  In the image forming units 12Bk, 12Y, 12M, and 12C, the surfaces of the photosensitive drums 13Bk, 13Y, 13M, and 13C are charged by the charging rollers 14Bk, 14Y, 14M, and 14C, and exposed by the LED heads 15Bk, 15Y, 15M, and 15C. As a result, an electrostatic latent image is formed. To the electrostatic latent images formed on the photosensitive drums 13Bk, 13Y, 13M, and 13C, the thinned toner on the developing rollers 16Bk, 16Y, 16M, and 16C is electrostatically attached, and the toner of each color. An image is formed. The toner images of the respective colors formed on the photosensitive drums 13Bk, 13Y, 13M, and 13C are transferred onto a sheet by transfer rollers 17Bk, 17Y, 17M, and 17C, and a color toner image is formed on the sheet. The toner remaining on the photosensitive drums 13Bk, 13Y, 13M, and 13C after the transfer is removed by a cleaning device (not shown).

  The sheet on which the color toner image is formed is sent to the fixing device 28. In the fixing device 28, a color toner image is fixed on a sheet, and a color image is formed. The sheet on which the toner image is fixed is conveyed while being sandwiched between a discharge roller and a pinch roller (not shown), and is discharged to the sheet stacker 29.

[Configuration of exposure apparatus (LED head)]
Next, the configuration of the LED heads 15Bk, 15Y, 15M, and 15C will be described together with the relationship between the photosensitive drums 13Bk, 13Y, 13M, and 13C and the LED heads 15Bk, 15Y, 15M, and 15C. In the image forming units 12Bk, 12Y, 12M, and 12C, the photosensitive drums 13Bk, 13Y, 13M, and 13C and the LED heads 15Bk, 15Y, 15M, and 15C have the same relationship with each other, and the LED heads 15Bk, 15Y. , 15M, 15C are the same as each other, and only the configuration of the LED head 15Bk will be described here, along with the relationship between the photosensitive drum 13Bk and the LED head 15Bk.

  FIGS. 2 and 3 are a transverse sectional view and a longitudinal sectional view, respectively, showing the LED head 15Bk and the photosensitive drum 13Bk in the first embodiment. As shown in FIGS. 2 and 3, the LED head 15Bk is disposed so as to face the photosensitive drum 13Bk. The LED head 15Bk includes a substrate 31, a rod lens array 33, a lens array holder 34, and a base 35.

  The substrate 31 has a lower surface (first surface) 31a and an upper surface (second surface) 31b on the opposite side, and extends in the longitudinal direction (the left-right direction in FIG. 2 and the direction orthogonal to the paper surface in FIG. 3). Has a long shape. A light emitting element array having a plurality of light emitting elements arranged along the longitudinal direction of the substrate 31 is mounted on the lower surface 31 a of the substrate 31. In this example, an LED array chip 32 including an LED array in which a plurality of LEDs are linearly arranged is arranged on the lower surface 31a of the substrate 31 so as to face the photosensitive drum 13Bk. The LED array chip 32 is configured, for example, by arranging a plurality of chips in one row. A driver IC (not shown) for controlling the LED array chip 32 is mounted on the substrate 31 together with the LED array chip 32. In the following description, the direction in which the surface (lower surface 31a) on which the light emitting element of the substrate 31 is disposed is referred to as “down”, and the opposite direction is referred to as “up”.

  The rod lens array 33 is a lens that converges light from a plurality of light emitting elements on the substrate 31, and is disposed so as to face the plurality of light emitting elements. Specifically, the rod lens array 33 is a converging lens that is disposed between the LED array chip 32 and the photosensitive drum 13Bk, has convergence, and converges the light emitted from each LED.

  The lens array holder 34 is a support member that supports the substrate 31 and the rod lens array 33. Specifically, the lens array holder 34 has a substrate contact surface S1 that contacts the lower surface 31a of the substrate 31, supports the substrate 31 on the substrate contact surface S1, and below the substrate contact surface S1. The rod lens array 33 is supported on the surface. The substrate contact surface S1 is provided, for example, so as to contact the peripheral portion of the LED array chip 32 on the lower surface 31a.

  The lens array holder 34 is, for example, a die-cast product manufactured by casting an aluminum material into a mold, a molded product made of general-purpose engineering plastic made of polyamide reinforced with glass fiber, or a composite molded product of sheet metal and the above-mentioned general-purpose engineering plastic. .

  Specifically, the lens array holder 34 is a hollow member that penetrates in a direction (vertical direction) perpendicular to the lower surface 31a of the substrate 31, and has an internal space that penetrates from below to above. The lens array holder 34 has a protrusion 34a provided so as to protrude toward the internal space, and a substrate contact surface S1 is formed on the substrate 31 side (upper side) of the protrusion 34a. A substrate 31 is installed on the substrate contact surface S1, and a rod lens array 33 is installed on the opposite side (lower side) of the substrate contact surface S1 from the substrate 31 side. That is, as shown in FIG. 3, the internal space of the lens array holder 34 communicates with the first region R1 that houses the rod lens array 33, and the first region R1 above the first region R1. A second region R2 formed in such a manner, and a region R3 formed to communicate with the second region R2 above the second region R2. The second region R2 and the third region R3 are partitioned by a plane including the substrate contact surface S1, and the width of the third region R3 is wider than the width of the second region R2. A step (projecting portion 34a) is formed on the inner peripheral portion of the second region R2, and the substrate contact surface S1 is formed on the upper surface of the step. In FIG. 3, the step is provided on both sides of the lens array holder 34 in the short direction (the direction perpendicular to the longitudinal direction and the vertical direction, also referred to as the width direction). In FIG. 2, the steps are provided on both sides of the lens array holder 34 in the longitudinal direction. The rod lens array 33 is disposed in the first region R1, and after being fixed to the lens array holder 34, the gap between the rod lens array 33 and the lens array holder 34 is prevented in order to prevent intrusion of light and foreign matter. Is sealed with the silicon agent 41.

  The base 35 is a pressing member (urging member) for pressing the substrate 31 against the substrate contact surface S1. The base 35 is a plate-like member that can be elastically deformed, and is installed on the upper surface 31 b of the substrate 31 along the longitudinal direction of the substrate 31. Specifically, the base 35 is a thin plate-like elastic member having a long shape.

  The base 35 is formed of a material having elasticity and flexibility, for example, a resin having thermoplasticity. In this example, general-purpose engineering plastic made of polyamide reinforced with glass fiber is used as the resin. Thereby, the heat resistance of the base 35, a load deflection temperature characteristic, etc. can be made high, and the elastic force stable for a long period of time can be maintained.

  By the way, in order to accurately form light on the surface of the photosensitive drum 13Bk, the distance from the surface of the LED array chip 32 to the incident end face (end face on which light enters) of the rod lens array 33 (with the LED array chip 32). (Distance between the rod lens array 33) L11 and the distance from the emission end face (end face from which light is emitted) of the rod lens array 33 to the surface of the photosensitive drum 13Bk (distance between the rod lens array 33 and the photosensitive drum 13Bk) It is necessary to adjust the distance L12 so that L12 is the same, that is, L11 = L12.

  Therefore, as shown in FIG. 2, eccentric cam mechanisms 42 and 43 as adjustment mechanisms are arranged at both ends in the longitudinal direction of the lens array holder 34. The eccentric cam mechanisms 42 and 43 are in contact with spacers 38a and 38b disposed on the surfaces of both ends in the axial direction of the photosensitive drum 13Bk, respectively. Coil springs 37 a and 37 b as urging members are disposed at both ends in the longitudinal direction of the base 35. The coil springs 37a and 37b press the LED head 15Bk in the direction of the photosensitive drum 13Bk, the abutment surfaces of the spacers 38a and 38b are brought into contact with the eccentric cam mechanisms 42 and 43, and the distance L12 is kept constant. By adjusting the eccentric cam mechanisms 42 and 43 (specifically, by rotating the cam body), the position of the lens array holder 34 with respect to the spacers 38a and 38b is adjusted.

  FIG. 4 is a diagram illustrating the configuration of the base 35, the substrate 31, and the lens array holder 34. 4 (a) and 4 (b) are a front view and a top view of the base 35, respectively. FIG. 4C is a top view of the substrate 31. 4D and 4E are a top view and a cross-sectional view of the lens array holder 34, respectively. FIG. 4E shows a cross-sectional view of the lens array holder 34 taken along a plane parallel to the vertical direction and the longitudinal direction. Hereinafter, the configuration of the LED head 15Bk will be described in more detail with reference to FIG.

  The base 35 has a pair of bent portions 4 and 5 that are bent or curved so as to protrude toward the substrate 31 at positions corresponding to both ends in the longitudinal direction of the substrate 31. For example, as shown in FIG. 2, the base 35 is engaged with the lens array holder 34 (or is fastened to the lens array holder 34), and thereby a direction (vertical direction) perpendicular to the upper surface 31 b of the substrate 31. ) And is installed in a state in which both ends in the longitudinal direction of the substrate 31 are pressed by the pair of bent portions 4 and 5 by the elastic restoring force. Specifically, the lens array holder 34 has at least one pressing portion that comes into contact with a surface (surface facing the upper side) facing the side opposite to the substrate 31 side of the base 35, and the base 35 has the lens array holder 34. By being in contact with at least one of the pressing parts, it is pressed in the direction (downward) in contact with the substrate 31 and installed in the elastically deformed state.

  In this example, the lens array holder 34 includes a pair of engaging portions 50a and 50b that engage with both ends in the longitudinal direction of the base 35 at both ends in the longitudinal direction. Specifically, the engaging portions 50 a and 50 b are pressing portions that come into contact with the surfaces facing the upper side of both ends in the longitudinal direction of the base 35. The base 35 includes a flat plate-like central portion 2 extending in the longitudinal direction of the substrate 31 and a pair of flat plate-like side portions 1a and 1b located on both sides of the central portion 2 in the longitudinal direction. The side portions 1a and 1b form bent portions 4 and 5 between the side portions 1a and 1b, respectively. That is, two boundary portions between the side portions 1a and 1b and the central portion 2 are located at positions corresponding to both ends in the longitudinal direction of the substrate 31 and are bent portions 4 and 5, respectively. Specifically, the side portions 1a and 1b are bent by an angle θ1 on the side opposite to the substrate 31 side with respect to the central portion 2, respectively. As shown in FIG. 2, both ends 49a and 49b of the base 35 are engaged with the engaging portions 50a and 50b of the lens array holder 34 (specifically, pressed and pressed), as shown in FIG. The side portions 1a and 1b are elastically deformed so as to approach the substrate 31 with the portions 4 and 5 as fulcrums, and are installed in a state in which both ends in the longitudinal direction of the substrate 31 are pressed by the bent portions 4 and 5 by the elastic restoring force.

  The lens array holder 34 is provided on both sides of the short direction (the direction perpendicular to the longitudinal direction and the vertical direction, also referred to as the width direction), and defines a space (third region R3) that accommodates the base 35. A pair of side walls 51a and 51b is provided. The width L3 of the base 35 in the short direction (the direction perpendicular to the longitudinal direction and the vertical direction, also referred to as the width direction) is the inner width between the side walls 51a and 51b (the width direction of the lens array holder 34). Inner wall width) The dimension is smaller than L1, and L3 <L1.

  The lens array holder 34 has a pair of projecting portions 52a and 52b provided above the substrate contact surface S1 so as to project toward the inner space on both sides in the longitudinal direction. On the substrate 31 side (lower side) of the protrusions 52a and 52b, downward flat portions are formed as the engaging portions 50a and 50b. The surfaces on the inner space side of the protrusions 52a and 52b constitute an inner wall surface extending in the vertical direction. The length L4 in the longitudinal direction of the base 35 before elastic deformation (before installation) has a dimension larger than the inner width (the inner wall width in the longitudinal direction of the lens array holder 34) L5 between the protrusions 52a and 52b, and L4> L5. The base 35 can be installed on the substrate 31 by being inserted between the two protrusions 52a and 52b while being elastically deformed in the vertical direction and the longitudinal direction from the direction facing the upper surface 31b of the substrate 31. It is configured as follows.

  The lens array holder 34 has a positioning portion for positioning the substrate 31 in a direction parallel to the substrate contact surface S1. Specifically, positioning holes 47 and 48 are provided at both longitudinal ends of the substrate 31, and the lens array holder 34 has positioning pins 46a and 46b that engage with the positioning holes 47 and 48, respectively, as positioning portions. Have. When the substrate 31 is assembled to the lens array holder 34, the positioning pins 46a and 46b are inserted into the positioning holes 47 and 48, respectively, so that the position of the substrate 31 in the lens array holder 34 is fixed. The positioning hole 48 is a long hole that is long in the longitudinal direction of the substrate 31.

  The above-described coil springs 37a and 37b are arranged so as to press the vicinity of the bent portions 4 and 5 of the base 35 (specifically, the vicinity of the inside in the longitudinal direction).

[Method of manufacturing exposure apparatus (LED head)]
FIG. 5 is a diagram for explaining a manufacturing procedure of the LED head 15Bk in the first embodiment. Hereinafter, the manufacturing procedure of the LED head 15Bk, particularly the assembly procedure of the base 35 will be described with reference to FIG. Arrows X1 and X2 in FIG. 5 represent the movement of the base 35.

  In assembling the LED head 15Bk, first, an assembly including the substrate 31 and the lens array holder 34 (that is, the lens array holder 34 to which the substrate 31 is attached) is prepared. For example, the substrate 31 is inserted into the lens array holder 34 to which the rod lens array 33 is attached, and placed on the substrate contact surface S1.

  Next, the base 35 is installed on the upper surface 31b of the substrate 31 of the assembly. Specifically, after one end portion (engaged portion) 49a in the longitudinal direction of the base 35 is engaged with the engagement portion 50a of the lens array holder 34, the bent portions 4 and 5 of the base 35 are connected to the upper surface of the substrate 31. The other end (engaged portion) 49b in the longitudinal direction of the base 35 is engaged with the lens array holder 34 while the base 35 is elastically deformed in the direction perpendicular to the upper surface 31b of the substrate 31 (vertical direction). Engage with the part 50b. More specifically, after the upper surface of the one end portion 49a of the base 35 is brought into contact with the engaging portion 50a, the bent portions 4 and 5 of the base 35 are pressed against the upper surface 31b of the substrate 31, and the base 35 is elastic in the vertical direction. The upper surface of the other end portion 49b of the base 35 is brought into contact with the engaging portion 50b while being deformed. For example, as shown in FIG. 5, the base 35 is inserted downward into the lens array holder 34, the upper surface of one end portion 49 a of the base 35 is brought into contact with the engaging portion 50 a, and the bent portion 4 is brought into contact with the substrate 31. Make contact. Next, when the base 35 is rotated in the direction of the arrow X2 while maintaining the contact between the one end portion 49a of the base 35 and the engaging portion 50a, the base 35 is moved to the center portion 2 by the rigidity of the bent portion 4. Begins to bend upward. Further, when the other end 49 b side of the base 35 is inserted downward, the bent portion 5 comes into contact with the substrate 31. The central portion 2 of the base 35 protrudes upward while maintaining the state where the one end portion 49a is in contact with the engaging portion 50a and the bent portions 4 and 5 are in contact with the substrate 31, and the bent portions 4 and 5 are pressed against the substrate 31. The other end 49b of the base 35 is moved downward while being bent so as to be. When the other end portion 49b reaches a position corresponding to the engaging portion 50b, the base 35 extends in the longitudinal direction, whereby the other end portion 49b contacts the engaging portion 50b.

  As described above, the base 35 is sandwiched between the upper surface 31 b of the substrate 31 and the engaging portions 50 a and 50 b of the lens array holder 34 as shown in FIG. 5D, and the side portions 1 a and 1 b are sandwiched between the substrates 31. It is installed in a state where it is bent so that the central portion 2 is convex upward. The angle θ2 formed by the side portions 1a and 1b and the upper surface 31b of the substrate 31 is smaller than the bending angle θ1 of the side portions 1a and 1b with respect to the central portion 2 before installation (θ2 <θ1). Due to the bending of the side portions 1a and 1b, an urging force (elastic restoring force) Pa from the bent portions 4 and 5 to the substrate 31 is generated. With this urging force Pa, the base 35 is locked to the lens array holder 34, and the substrate 31 is pressed against the substrate contact surface S 1 of the lens array holder 34.

  As shown in FIG. 5, the distance from the substrate contact surface S1 to the engaging portion 50b (50a) is H1, the thickness of the substrate 31 is t, and the end portion 49b of the base 35 in the state before the base 35 is assembled. Assuming that the distance from the surface 35a of the base 35 in contact with the substrate 31 to the upper end portion 49bx (49ax) of the end portion 49b (49a) in the bending direction (vertical direction in the figure) of (49a) is H2, the LED head 15Bk Is formed so as to satisfy H2 + t> H1. By doing so, in the state of FIG. 5D, the force Pa in the direction in which the substrate 31 is pressed against the substrate contact surface S1 side of the lens array holder 34 using the bent portions 4 and 5 as a force point always acts. Further, since the urging force Pa of the base 35 is concentrated on the bent portions 4 and 5, the substrate 31 is not easily displaced.

  When the base 35 is assembled, the bent portions 4 and 5 of the base 35 are in contact with the substrate 31 until the other end portion 49b of the base 35 is engaged with the engaging portion 50b of the lens array holder 34. The urging force Px in the longitudinal direction when the central portion 2 is restored acts on the substrate 31 from 4 and 5. However, since the substrate 31 is locked in the longitudinal direction by the positioning pins 46a and 46b of the lens array holder 34, the influence of the biasing force Px on the substrate 31 (for example, LEDs arranged in a row on the substrate 31). There is almost no influence on the arrangement in the longitudinal direction. Further, when the base 35 is assembled, the base 35 is not elastically deformed in the short direction, and no force in the short direction acts on the substrate 31. Further, the width L3 in the short direction of the base 35 is smaller than the inner wall width L1 in the short direction of the lens array holder 34, and the force in the short direction against the side walls 51a and 51b of the lens array holder 34 when the base 35 is assembled. Does not work.

[effect]
According to the first embodiment described above, the following effects (1) to (7) can be obtained.
(1) In the present embodiment, the base for pressing the substrate against the substrate contact surface is a pair of bent portions bent or curved so as to protrude toward the substrate side at positions corresponding to both ends in the longitudinal direction of the substrate. And is elastically deformed in a direction perpendicular to the upper surface of the substrate by being engaged with the lens array holder, and is configured to be installed in a state where the substrate is pressed by a pair of bent portions by the elastic restoring force. . For this reason, according to this Embodiment, a board | substrate can be pressed on a board | substrate contact surface with a simple structure. Specifically, protrusions, slits, and bridges are formed on the base, grooves are formed on the inner wall of the lens array holder, and the base protrusions are pushed into the grooves of the lens array holder to lock the base to the lens array holder. Compared with the structure to perform, a board | substrate can be pressed with a simple structure.

  (2) In the exposure apparatus described in Patent Document 1, when the protrusion of the base is pushed into the groove of the lens array holder, a short-direction force acts on the substrate, thereby deteriorating the quality of the exposure apparatus. There is a case. For example, the warpage of the central portion in the longitudinal direction of the light emitting element array on the substrate may change, and the quality of the exposure apparatus may deteriorate. On the other hand, in the present embodiment, it can be configured so that a force in the short direction against the substrate does not occur when the base is assembled, and deterioration of quality due to the force can be avoided or reduced.

  (3) In the exposure apparatus described in Patent Literature 1, when the base is inserted into the lens array holder, the force in the short direction that widens the side wall of the lens array holder from the protruding portion of the base to the side wall of the lens array holder. May affect the quality of the exposure apparatus. For example, the warp tendency of the rod lens array attached to the lens array holder may change, and the quality of the exposure apparatus may deteriorate. On the other hand, in the present embodiment, it can be configured not to generate a force in the short direction with respect to the lens array holder, and deterioration of quality due to the force can be avoided or reduced. For example, by making the width in the short direction of the base smaller than the inner wall width of the lens array holder, it is possible to prevent a force from acting on the side wall of the lens array holder from the base. Can be prevented from being deformed.

  (4) The lens array holder has a pressing portion that contacts a surface of the base facing away from the substrate side, and the base contacts the pressing portion of the lens array holder and contacts the substrate by the pressing portion. By being pressed, it is installed in an elastically deformed state. According to this aspect, it is possible to support the base in an elastically deformed state by applying a force in the direction of contacting the substrate to the base with a simple configuration.

  (5) The lens array holder has a pair of pressing portions that come into contact with both ends in the longitudinal direction of the base as the pressing portion. The base is a pair of flat plate-like central portions extending in the longitudinal direction of the substrate, and a pair of flat plate-like shapes located on both sides of the central portion in the longitudinal direction so as to form the pair of bent portions between the central portions. And side portions. The base is pressed by the pair of pressing portions, elastically deformed so that the pair of side portions approach the substrate with the pair of bent portions as fulcrums, and presses both longitudinal ends of the substrate with the pair of bent portions. Installed at. According to this aspect, the substrate can be pressed against the substrate contact surface with a simpler configuration.

  (6) The lens array holder has a positioning portion for positioning the substrate in a direction parallel to the substrate contact surface. According to this aspect, it is possible to avoid or reduce the influence on the quality of the exposure apparatus due to the force in the direction parallel to the substrate contact surface (for example, the longitudinal direction) that acts on the substrate from the base when the base is installed. it can.

  (7) When installing the base on the substrate, the surface of the one end of the base in the longitudinal direction facing the side opposite to the substrate is brought into contact with the pressing portion provided on one side of the lens array holder, and then the pair The surface of the other end of the base that faces away from the substrate is the other side of the lens array holder while the base is elastically deformed in a direction perpendicular to the upper surface of the substrate. It is made to contact with the holding part provided in. According to this aspect, the base can be assembled on the substrate by a simple method.

Embodiment 2. FIG.
The exposure apparatus (LED head) in the second embodiment will be described below. The LED head according to the present embodiment is different from the LED head according to the first embodiment in the configuration of the base, and the other parts are substantially the same. In the following description, the description of the same parts as those in the first embodiment is omitted or simplified, and the same or corresponding elements as those in the first embodiment are denoted by the same reference numerals.

  FIG. 6 is a cross-sectional view showing the LED head 15Bk and the photosensitive drum 13Bk in the second embodiment. FIG. 7 is a diagram showing a configuration of the base 35 in the second embodiment. 7A and 7B are a front view and a top view of the base 35, respectively.

  In the present embodiment, the base 35 further includes at least one pressing portion that presses the central portion in the longitudinal direction of the substrate 31 with an elastic restoring force, in addition to the pair of bent portions 4 and 5. Specifically, the base 35 has a protruding portion that protrudes toward the substrate 31 at a position corresponding to the central portion in the longitudinal direction of the substrate 31, and presses the central portion in the longitudinal direction of the substrate 31 with the protruding portion by an elastic restoring force. It is installed in the state to do. More specifically, the base 35 includes leaf spring portions 3a and 3b provided so as to protrude from the central portion 2 toward the substrate 31 in addition to the central portion 2 and the side portions 1a and 1b. The plate spring portions 3a and 3b are configured such that the fixed end portions are fixed to the central portion 2 and the free end portions (tip portions) 6a and 6b are located closer to the substrate 31 than the central portion 2. The leaf spring portions 3a and 3b are flat members provided obliquely from the central portion 2 toward the substrate 31 and form an angle θ3 with respect to the central portion 2. That is, the leaf spring portions 3a and 3b are bent by an angle θ3 toward the substrate 31 with respect to the central portion 2. In the example of FIG. 7, two rectangular cutout portions 60 a and 60 b extending in the longitudinal direction are formed in the central portion 2 of the base 35, and from the end portions of the cutout portions 60 a and 60 b on the outer side in the longitudinal direction. Leaf spring portions 3a and 3b are formed to extend inward. The leaf spring portions 3a and 3b are formed by cutting and raising a plate-like member for forming the central portion 2, for example.

  As shown in FIG. 6, both ends 49a and 49b of the base 35 are engaged with the engaging portions 50a and 50b of the lens array holder 34 (specifically, abutted and pressed) and bent. With the end portions 6a, 6b of the portions 4, 5 and the leaf spring portions 3a, 3b as fulcrums, the side portions 1a, 1b approach the substrate 31 and elastically deform so that the leaf spring portions 3a, 3b approach the center portion 2, In the state where the longitudinal ends of the substrate 31 are pressed by the bent portions 4 and 5 by the elastic restoring force, and the longitudinal central portions of the substrate 31 are pressed by the tip portions (pressing portions) 6a and 6b of the leaf spring portions 3a and 3b. Installed.

  FIG. 8 is a diagram for explaining a manufacturing procedure of the LED head 15Bk in the second embodiment. Hereinafter, the manufacturing procedure of the LED head 15Bk, in particular, the assembling procedure of the base 35 will be described with reference to FIG. The arrow lines X3 and X4 in FIG. 8 represent the movement of the base 35.

  In assembling the LED head 15Bk, first, an assembly including the substrate 31 and the lens array holder 34 (that is, the lens array holder 34 to which the substrate 31 is attached) is prepared.

  Next, the base 35 is installed on the upper surface 31b of the substrate 31 of the assembly. Specifically, after one end portion (engaged portion) 49a in the longitudinal direction of the base 35 is engaged with the engaging portion 50a of the lens array holder 34, the bent portions 4 and 5 of the base 35 and the leaf spring portion 3a. , 3b are pressed against the upper surface 31b of the substrate 31 and the base 35 is elastically deformed in the direction perpendicular to the upper surface 31b of the substrate 31 (vertical direction). The end (engaged portion) 49 b is engaged with the engaging portion 50 b of the lens array holder 34. More specifically, after the upper surface of the one end portion 49a of the base 35 is brought into contact with the engaging portion 50a, the bent portions 4 and 5 of the base 35 and the tip end portions 6a and 6b of the leaf spring portions 3a and 3b are connected to the substrate 31. The upper surface of the other end portion 49b of the base 35 is brought into contact with the engaging portion 50b while the base 35 is elastically deformed in the vertical direction. For example, as shown in FIG. 8, the base 35 is inserted downward into the lens array holder 34, the upper surface of one end 49a of the base 35 is brought into contact with the engaging portion 50a, and the bent portion 4 is brought into contact with the substrate 31. Make contact. Next, when the base 35 is rotated in the direction of the arrow X4 while maintaining the contact between the one end portion 49a of the base 35 and the engaging portion 50a, the base 35 is moved to the center portion 2 by the rigidity of the bent portion 4. Begins to bend upward. When the other end 49b side of the base 35 is further inserted downward, the tip 6a, the tip 6b, and the bent part 5 come into contact with the substrate 31 in this order. One end portion 49a is in contact with the engaging portion 50a, and the bent portions 4, 5 and the tip portions 6a, 6b are maintained in contact with the substrate 31, and the bent portions 4, 5 and the tip portions 6a, 6b are pressed against the substrate 31. However, the other end 49b of the base 35 is moved downward while the central portion 2 of the base 35 is bent so as to protrude upward. When the other end portion 49b reaches a position corresponding to the engaging portion 50b, the base 35 extends in the longitudinal direction, whereby the other end portion 49b contacts the engaging portion 50b.

  As described above, the base 35 is sandwiched between the upper surface 31b of the substrate 31 and the engaging portions 50a and 50b of the lens array holder 34, and the side portions 1a and 1b are placed on the substrate 31 as shown in FIG. It is installed in a state where it is bent so that the central portion 2 is convex upward. The angle θ2 formed by the side portions 1a and 1b and the upper surface 31b of the substrate 31 is smaller than the bending angle θ1 of the side portions 1a and 1b with respect to the central portion 2 before installation (θ2 <θ1). Due to the bending of the side portions 1a and 1b, an urging force (elastic restoring force) Pa from the bent portions 4 and 5 to the substrate 31 is generated. In addition, the base 35 is installed in a state where the leaf spring portions 3 a and 3 b are bent so as to approach the center portion 2. In this state, the angle θ4 formed by the leaf spring portions 3a, 3b and the central portion 2 is smaller than the angle θ3 formed by the leaf spring portions 3a, 3b and the central portion 2 before installation (θ4 < θ3). Due to the bending of the leaf spring portions 3a and 3b, an urging force (elastic restoring force) Pb from the tip portions 6a and 6b of the leaf spring portions 3a and 3b to the substrate 31 is generated. The base 35 is locked to the lens array holder 34 by the urging forces Pa and Pb, and both end portions and the center portion of the substrate 31 in the longitudinal direction are pressed against the substrate contact surface S1 of the lens array holder 34.

According to the second embodiment described above, the following effects (8) to (10) can be obtained in addition to the effects (1) to (7).
(8) In the present embodiment, the base further includes a pressing portion that presses the central portion in the longitudinal direction of the substrate with an elastic restoring force. According to the present embodiment, the substrate can be pressed well (or stably) against the substrate contact surface. Specifically, by pressing the central portion in the longitudinal direction of the substrate, it is possible to avoid or reduce the floating of the central portion in the longitudinal direction of the substrate from the substrate contact surface, particularly when the total length of the substrate is large. it can.

  (9) The lens array holder has a pair of pressing portions that come into contact with both ends in the longitudinal direction of the base. The base is a flat central portion extending in the longitudinal direction of the substrate, and a pair of flat flat sides positioned on both sides of the central portion so as to form a pair of bent portions with the central portion. And a flat plate spring portion provided so as to protrude from the center portion toward the substrate side. Then, the base is pressed by the pair of pressing portions, elastically deformed so that the pair of side portions approach the substrate and the leaf spring portion approaches the central portion, with the pair of bent portions and the tip portions of the leaf spring portions as fulcrums, It is installed in such a state that both ends in the longitudinal direction of the substrate are pressed by the pair of bent portions, and the central portion in the longitudinal direction of the substrate is pressed by the tip of the leaf spring portion. According to this aspect, the substrate can be favorably (or stably) pressed against the substrate contact surface with a simple configuration.

  (10) When installing the base on the substrate, the surface of the one end of the base in the longitudinal direction facing the side opposite to the substrate is brought into contact with the pressing portion provided on one side of the lens array holder, and then the pair The surface of the other end in the longitudinal direction of the base that faces away from the substrate side is pressed into the lens array holder while the base is elastically deformed in a direction perpendicular to the upper surface of the substrate while pressing the bent portion and the pressing portion of the lens array holder. It is made to contact | abut to the holding | suppressing part provided in the other side. According to this aspect, the base can be assembled on the substrate by a simple method.

  In the present specification, the “end portion” includes not only a strict “end” but also “a portion in the vicinity of the end”.

  Further, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist of the present invention. For example, in the above description, the image forming apparatus (color printer) shown in FIG. 1 has been exemplified. However, the exposure apparatus can be applied to other types of image forming apparatuses such as other types of printers, copiers, facsimile machines, and multifunction machines. May be applied. Further, the configuration of the exposure apparatus is not limited to that shown in the above embodiment, and may be changed as appropriate.

  1a, 1b side part, 2 center part, 3a, 3b leaf spring part, 4, 5 bent part, 6a, 6b tip part (pressing part), 11 image forming apparatus, 15Bk, 15Y, 15M, 15C LED head (exposure apparatus) ), 31 substrate, 31a lower surface (first surface), 31b upper surface (second surface), 32 LED array chip, 33 rod lens array, 34 lens array holder, 35 base, 46a, 46b positioning pins, 47, 48 Positioning holes, 50a, 50b engaging portions.

Claims (10)

A substrate having a first surface and a second surface opposite to the first surface, wherein a plurality of light emitting elements are disposed on the first surface along a longitudinal direction thereof;
A substrate contact surface that contacts the first surface of the substrate, and a support member that supports the substrate on the substrate contact surface;
An elastically deformable plate-like pressing member that is installed on the second surface of the substrate along the longitudinal direction of the substrate and presses the substrate against the substrate contact surface, the longitudinal direction of the substrate A pressing member having a pair of bent portions bent or curved so as to protrude toward the substrate side at positions corresponding to both end portions;
With
The pressing member is elastically deformed in a direction perpendicular to the second surface of the substrate by engaging with the support member, and the elastic restoring force presses both ends in the longitudinal direction of the substrate with the pair of bent portions. Configured to be installed in a state
An exposure apparatus characterized by that. The support member has a pressing portion that comes into contact with a surface of the pressing member facing the side opposite to the substrate side,
The pressing member is in contact with the pressing portion of the support member and is installed in the elastically deformed state by being pressed in the direction of contacting the substrate by the pressing portion.
The exposure apparatus according to claim 1, wherein: The support member has a pair of pressing portions that contact the both longitudinal ends of the pressing member as the pressing portion,
The pressing member is
A flat central portion extending in the longitudinal direction of the substrate;
A pair of flat plate-like side portions provided on both sides in the longitudinal direction of the central portion and provided to form the pair of bent portions with the central portion;
Have
A state of being pressed by the pair of pressing portions, elastically deforming so that the pair of side portions approach the substrate with the pair of bent portions as fulcrums, and pressing both ends in the longitudinal direction of the substrate by the pair of bending portions Installed in the
The exposure apparatus according to claim 2, wherein:   The exposure apparatus according to claim 1, wherein the pressing member further includes a pressing portion that presses a central portion in the longitudinal direction of the substrate with an elastic restoring force. The support member has a pair of pressing portions that contact the both longitudinal ends of the pressing member as the pressing portion,
The pressing member is
A flat central portion extending in the longitudinal direction of the substrate;
A pair of flat plate-like side portions provided on both sides in the longitudinal direction of the central portion and provided to form the pair of bent portions with the central portion;
A flat leaf spring portion provided so as to protrude from the central portion toward the substrate;
Have
Elastically deformed so that the pair of side parts approach the substrate and the leaf spring part approaches the center part with the pair of bent parts and the tip part of the leaf spring part as a fulcrum, being pressed by the pair of holding parts. Then, the pair of bent portions are installed in a state in which both end portions in the longitudinal direction of the substrate are pressed, and the center portion in the longitudinal direction of the substrate is pressed at the distal end portion of the leaf spring portion as the pressing portion.
The exposure apparatus according to claim 4, wherein:   6. The exposure apparatus according to claim 1, wherein the support member has a positioning portion for positioning the substrate in a direction parallel to the substrate contact surface.   7. The lens according to claim 1, further comprising a lens that is supported by the support member so as to face the plurality of light emitting elements and converges light from the plurality of light emitting elements. Exposure device. An electrostatic latent image carrier;
An exposure device that irradiates the electrostatic latent image carrier with light to form an electrostatic latent image;
Have
The exposure apparatus includes:
A substrate having a first surface and a second surface opposite to the first surface, wherein a plurality of light emitting elements are disposed on the first surface along a longitudinal direction thereof;
A substrate contact surface that contacts the first surface of the substrate, and a support member that supports the substrate on the substrate contact surface;
An elastically deformable plate-like pressing member that is installed on the second surface of the substrate along the longitudinal direction of the substrate and presses the substrate against the substrate contact surface, the longitudinal direction of the substrate A pressing member having a pair of bent portions bent or curved so as to protrude toward the substrate side at positions corresponding to both end portions;
With
The pressing member is elastically deformed in a direction perpendicular to the second surface of the substrate by engaging with the support member, and the elastic restoring force presses both ends in the longitudinal direction of the substrate with the pair of bent portions. Configured to be installed in a state
An image forming apparatus. A substrate having a first surface and a second surface opposite to the first surface, wherein a plurality of light emitting elements are disposed on the first surface along a longitudinal direction thereof, and a first of the substrate Preparing an assembly having a substrate contact surface that contacts the surface of the substrate and a support member that supports the substrate on the substrate contact surface;
An elastically deformable plate-like pressing member for pressing the substrate against the substrate contact surface, which is bent or curved so as to protrude toward the substrate at positions corresponding to both longitudinal ends of the substrate. Installing a pressing member having a pair of bent portions on the second surface of the substrate along the longitudinal direction of the substrate;
Including
In the step of installing, the surface of the one end portion of the pressing member in the longitudinal direction facing the side opposite to the substrate side is brought into contact with a pressing portion provided on one side of the support member, and then the pair of bending portions The portion is pressed against the second surface of the substrate, and the pressing member is elastically deformed in a direction orthogonal to the second surface of the substrate, while the other end portion in the longitudinal direction of the pressing member is opposite to the substrate side. A surface facing side is brought into contact with a pressing portion provided on the other side of the support member;
An exposure apparatus manufacturing method characterized by the above. The pressing member further includes a pressing portion that presses the central portion in the longitudinal direction of the substrate with an elastic restoring force,
In the step of installing, the surface of the one end portion of the pressing member in the longitudinal direction facing the side opposite to the substrate side is brought into contact with a pressing portion provided on one side of the support member, and then the pair of bending portions The substrate at the other end in the longitudinal direction of the pressing member while pressing the pressing portion against the second surface of the substrate and elastically deforming the pressing member in a direction perpendicular to the second surface of the substrate A surface facing away from the side is brought into contact with a pressing portion provided on the other side of the support member;
An exposure apparatus manufacturing method according to claim 9.

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