Illumination device and image reading device including the same

An illumination device includes a light emitting unit, a light guide member, in which one end part in a longitudinal direction has a rod shape facing the light emitting unit, and is formed on a peripheral surface thereof with a light emitting part extending in the longitudinal direction, and a support member that extends along the longitudinal direction of the light guide member and supports the light guide member, wherein the support member is divided into a one side divided part and the other side divided part in the longitudinal direction of the light guide member, and a gap is provided between a support surface of the light guide member in the one side divided part and a support surface of the light guide member in the other side divided part.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2017-176983 filed on Sep. 14, 2017, the entire contents of which are incorporated herein by reference.

BACKGROUND

The technology of the present disclosure relates to an illumination device and an image reading device including the same.

In the related art, there has been known an image reading device that illuminates linear light toward a document placed on a document table and leads reflected light to a photoelectric conversion unit (for example, a CCD sensor) via a mirror and the like, thereby reading an image of the document.

In this type of image reading device, there has been proposed an illumination device using a light emitting diode and a rod-like light guide member in order to generate linear light. One end part of the light guide member faces the light emitting diode. The light guide member is formed on the outer peripheral surface thereof with a light emitting part extending in a longitudinal direction of the light guide member. Light emitted from the light emitting diode is diffused to the whole area in the longitudinal direction by the light guide member, and is emitted from the light emitting part as linear light.

The light guide member is supported by a support member extending along the longitudinal direction of the light guide member. The support member has a reflecting plate part that covers an opposite side of the light emitting part of the light guide member, and first and second support parts that support both end parts of the light guide member. Both end parts of the light guide member are fitted into hole parts formed in the first and second support parts, so that movement of the light guide member in the longitudinal direction and a rotation direction is regulated.

SUMMARY

An illumination device according to one aspect of the present disclosure includes a light emitting unit, a light guide member, and a support member. The light guide member has a rod shape. One end part in a longitudinal direction of the light guide member faces the light emitting unit. Furthermore, the light guide member is provided on the peripheral surface thereof with a light emitting part extending in the longitudinal direction. The support member extends in the longitudinal direction of the light guide member and supports the light guide member.

Furthermore, the support member is divided into a one side divided part and the other side divided part in the longitudinal direction of the light guide member. A gap is provided between the one side divided part and the other side divided part. The gap extends in a direction crossing the longitudinal direction of the light guide member and absorbs thermal expansion deformation of each divided part in the longitudinal direction.

DETAILED DESCRIPTION

Hereinafter, an example of an embodiment will be described in detail on the basis of the drawings. It is noted that the technology of the present disclosure is not limited to the following embodiments.

FIG. 1illustrates a schematic configuration diagram of an image forming apparatus1including an illumination device in an embodiment. The image forming apparatus1is a composite type image forming apparatus (a multifunctional peripheral) having a scanner function, a facsimile function, and a copy function in addition to a print function. In the following description, it is assumed that a front side and a rear side indicate a front side and a rear side of the image forming apparatus1, a left side and a right side indicate a left side and a right side when the image forming apparatus1is viewed from the front side (a side of an operation panel8to be described later), and an upper side and a lower side indicate an upper side and a lower side of the image forming apparatus1.

As illustrated inFIG. 1, the image forming apparatus1includes an image forming apparatus body2and an image reading device3disposed above the image forming apparatus body2. The image forming apparatus body2has a print unit4disposed at an intermediate part in an up and down direction of the image forming apparatus body2, and a plurality of sheet feeding cassettes5disposed below the print unit4. The sheet feeding cassettes5receive different sizes of sheets therein respectively. The print unit4performs printing on the sheet supplied from the sheet feeding cassettes5on the basis of predetermined image data. As a printing scheme of the print unit4, an electrophotographic scheme is employed. That is, the print unit4forms an electrostatic latent image by irradiating a surface of a photosensitive drum with laser light corresponding to image data, develops the electrostatic latent image by using toner, and transfers the developed image to the sheet.

FIG. 2illustrates a schematic configuration diagram of the image reading device3in the embodiment.FIG. 3illustrates a perspective view of a housing20of the image reading device3in the embodiment. The image reading device3is a device that optically reads an image of a document (a document sheet) on a contact glass11and generates image data corresponding to the image of the document. In the present embodiment, for the image reading device3, a front and rear direction corresponds to a “main scanning direction” and a right and left direction corresponds to a “sub-scanning direction”.

As illustrated inFIG. 2, the image reading device3includes the housing20provided on the upper surface thereof with the contact glass11, a document cover6that is mounted at the housing20so as to be openable and closable and covers the upper surface of the contact glass11in a closed state, and a reading unit30received in the housing20. The document cover6is integrally formed with an automatic document feeder (ADF)7. In addition, as illustrated inFIG. 1, from a front surface part of the image reading device3, the operation panel8is formed to protrude. The operation panel8is provided with an operation unit9including a numeric keypad and a start key, and a display unit10including a liquid crystal display.

The image reading device3performs a document reading operation that reads an image of a document. The document reading operation includes a manual mode in which a document placed on the contact glass11by a user is read, and an automatic sheet feeding mode in which a document automatically supplied by the automatic document feeder7is read.

The housing20includes an approximately rectangular parallelepiped-like box body20a(seeFIG. 3) opened upward, and the contact glass11mounted at an upper opening of the box body20a.FIG. 3illustrates a state in which the contact glass11has been removed. As illustrated inFIG. 2, the contact glass11includes a first contact glass11aon which a document to be read in the document reading operation of the manual mode is placed, and a second contact glass11bhaving an upper side through which a document to be read in the document reading operation of the automatic sheet feeding mode passes. The first contact glass11ais formed in a rectangular plate shape and occupies a wide range on the upper surface of the housing20. The second contact glass11bis formed in a rectangular plate shape elongated in the front and rear direction and is disposed at a left side of the first contact glass11aon the upper surface of the housing20.

The document cover6is placed at the upper side of the housing20. The document cover6is mounted at the housing20so as to be openable and closable by using a hinge (not illustrated) provided at a rear end part of the housing20as a fulcrum. The document cover6covers an approximate entire area of the upper surface of the housing20in a closed state.

The automatic document feeder7is received in the document cover6. The automatic document feeder7conveys a document set in a document feeding tray7aalong a predetermined conveyance path and allows the document to pass through a reading position on the second contact glass11b. The document having passed through the reading position is discharged to a document discharge tray7b.

As illustrated inFIG. 2, the reading unit30includes a first moving carriage31, a second moving carriage32, a condensing lens unit33, and an imaging element34. In the first moving carriage31, an illumination device40and a first reflecting mirror41are installed. In the second moving carriage32, a second reflecting mirror42and a third reflecting mirror43are installed.

In the reading unit30, when each of the document reading operation and a document size detection operation is performed, the illumination device40irradiates a document on the contact glass11with light. Reflection light reflected from the document surface after the irradiation from the illumination device40is reflected in sequence of the first reflecting mirror41, the second reflecting mirror42, and the third reflecting mirror43. The second reflecting mirror42and the third reflecting mirror43invert an optical path. The reflected light of the third reflecting mirror43passes through the condensing lens unit33, so that an image of the reflected light is formed on an imaging surface of the imaging element34. The imaging element34includes a charge coupled device (CCD) and the like and photoelectrically converts the light received in the imaging surface into an analog electric signal. The analog electric signal is converted into a digital electric signal by an A/D conversion circuit (not illustrated) and then is inputted to a controller15as image data.

The moving carriages31and32are driven by a driving mechanism (not illustrated) using a driving motor such as a stepping motor. The first moving carriage31reciprocally moves along the lower surfaces of the first contact glass11aand the second contact glass11bin the right and left direction. The second moving carriage32reciprocally moves in the right and left direction by a half of an amount of movement of the first moving carriage31while following the first moving carriage31. Specifically, in the document reading operation of the manual mode, the first moving carriage31moves in the right direction from directly under (a home position) the left end of the first contact glass11a. In this movement, light is irradiated toward a document from the illumination device40. On the other hand, in the document reading operation of the automatic sheet feeding mode, the first moving carriage31moves directly under the second contact glass11band enters a stationary state. In this stationary state, light is irradiated toward a document from the illumination device40.

The illumination device40irradiates illumination light by employing a document on the contact glass11as a focal position. As illustrated inFIG. 4, the illumination device40includes a first illumination unit51and a second illumination unit52that irradiate linear illumination light long in the front and rear direction, and a resinous support member53that support the first illumination unit51and the second illumination unit52. The illumination device40irradiates light at a position facing the first contact glass11aor the second contact glass11bin accordance with the position of the first moving carriage31. The first illumination unit51and the second illumination unit52have the same configuration.

As illustrated inFIG. 5, the first illumination unit51includes a first light source61and a straight rod-like first light guide member71. The second illumination unit52includes a second light source62and a straight rod-like second light guide member72. In the illumination units51and52, each light guide members71and72is provided with one light source61and one light source62(corresponding to light emitting units) respectively. In the illumination device40, the two light sources61and62are provided.

Each of the light sources61and62is a white light emitting diode (LED) having a thin disc shape and emitting white light. As an example of the white LED, it is possible to use a high luminance LED package. The high luminance LED package is configured by sealing a GaN-based or InGaN-based semiconductor light emitting element for emitting blue light or ultraviolet light with transparent resin containing a fluorescent substance. Furthermore, the shape of the white LED is not limited to the disc shape and can employ a square shape. Each of the light sources61and62is disposed facing one end surface of each of the light guide members71and72. The light sources61and62are mounted on LED boards63and64, respectively (seeFIG. 4).

Each of the light guide members71and72is formed by a light transmitting resin material such as acrylic resin. As illustrated inFIG. 5andFIG. 6, the light guide members71and72have light guide bodies71aand72a, flat plate parts71band72b, and claw parts71cand72c, respectively. The light guide bodies71aand72aare column parts having approximately semicircular sections extending in the front and rear direction. The light guide bodies71aand72aprotrude from center parts in the width direction of the flat plate parts71band72bextending in the front and rear direction.FIG. 6illustrates the sectional shape of only the first light guide member71; however, the second light guide member72have the same sectional shape as that of the first light guide member71. Each of the light guide members71and72has a sectional hat shape as illustrated inFIG. 6. Each of the claw parts71cand72cprotrudes from an outer end part in the right and left direction of each of the flat plate parts71band72bat an end part of a light incident part Si side of each of the light guide members71and72as illustrated inFIG. 5. It is noted that the other drawings, other thanFIG. 6, do not illustrate reference numerals So, Si, and Sr for the purpose of visibility.

In the light guide members71and72, incident light from end surfaces facing the light sources61and62respectively corresponding to the light guide members71and72propagates, is converted into linear illumination light, and is emitted. Specifically, in each of the light guide members71and72, one end surface facing each of the light sources61and62serves as the light incident part Si (seeFIG. 6), an upper surface (a surface facing the contact glass11) is provided with a light emitting part So for emitting light, and a surface (an opposite surface of the light emitting part So) facing the light emitting part So is provided with a light reflecting part Sr. The light emitting part So and the light reflecting part Sr are formed over the whole area in the front and rear direction of the light guide bodies71aand72a, respectively.

As illustrated inFIG. 8, the first light guide member71and the second light guide member72are mounted spaced apart from each other in the support member53in parallel to each other in the right and left direction. The support member53is mounted in the first moving carriage31(seeFIG. 2) such that the light guide members71and72extend along the front and rear direction. The first light guide member71is disposed at a right side of the second light guide member72when viewed from the front side of the housing20.

Furthermore, in the present embodiment, as illustrated inFIG. 5, the first light guide member71is mounted in the support member53such that the first light source61is positioned at the front side, and the second light guide member72is mounted in the support member53such that the second light source62is positioned at the rear side. The first light source61is positioned in a front side area of the housing20and emits incident light to the first light guide member71toward the rear side. The second light source is positioned in a rear side area of the housing20and emits incident light to the second light guide member72toward the front side.

As illustrated inFIG. 8, the first light guide member71and the second light guide member72are supported by the support member53at the same height. In the support member53, a path of light toward the first reflecting mirror41from the first contact glass11ais formed inside between the first light guide member71and the second light guide member72. The first light guide member71and the second light guide member72are inclined by a predetermined angle and are provided with an orientation in which the light emitting part So (seeFIG. 6) are slightly directed inward. In the first light guide member71, the light emitting part So faces the left obliquely upward when viewed from the front side of the housing20. In the second light guide member72, the light emitting part So faces the right obliquely upward when viewed from the front side of the housing20.

—Details of Support Member—

Details of the support member53will be described with reference toFIG. 4,FIG. 7, andFIG. 8. The support member53is mounted at a bottom plate part of the first moving carriage via a sheet metal member80. The support member53is divided into a one side divided part531and the other side divided part532(seeFIG. 15). The division structure of the support member53will be described later.

The sheet metal member80includes a bottom side sheet metal80aon which the support member53is placed. Four sides of the support member53are surrounded by a front side sheet metal80b, a rear side sheet metal80c, a left side sheet metal80d, and a right side sheet metal80e, which are obtained by cutting and raising a part of the sheet metal member80as illustrated inFIG. 4. A lower surface of the support member53is supported by abutting the bottom side sheet metal80aat both end parts and an intermediate part thereof in the front and rear direction (seeFIG. 8). The entire lower surface of the support member53may be allowed to abut the bottom side sheet metal80a.

Referring toFIG. 7, the support member53has a first reflecting-side support part53a, a second reflecting-side support part53b, a front end support plate53d, and a rear end support plate53e. The first and second reflecting-side support parts53aand53bare disposed to extend in the front and rear direction in parallel to each other while being spaced apart from each other in the right and left direction. The first and second reflecting-side support parts53aand53bserve as flat plate support parts that support the flat plate parts71band72bof the first and second light guide members71and72from the sides of the light reflecting parts Sr (seeFIG. 6), respectively. The reflecting-side support parts53aand53bare connected to each other via a flat plate53fextending in the front and rear direction. The flat plate53fis formed with a rectangular through hole53gextending in the front and rear direction. In the through hole53g, a pair of inner pressing members81, which will be described later, are disposed by passing through the through hole53gin an up and down direction.

Referring toFIG. 8, a support surface53sof the first reflecting-side support part53aand a support surface53tof the second reflecting-side support part53bare inclined such that inner end edges are lower than outer end edges when viewed from the front and rear direction. The support surfaces53sand53tbecome white reflecting surfaces capable of reflecting light toward the inner sides of the light guide members71and72. The reflecting surfaces are not limited to the white color and it is sufficient if the reflecting surfaces have colors with high reflectivity of light or the reflecting surfaces may be made of a material that easily reflects light or may be subjected to a surface treatment. The first reflecting-side support part53aand the second reflecting-side support part53bserve as reflecting surface formation parts.

The support surfaces53sand53tabut the lower surfaces of the flat plate parts71band72bof the light guide members71and72in the whole area in the front and rear direction thereof, respectively. Each of the support surfaces53sand53tis formed at the center part in the width direction thereof with a dish-like groove53mextending in the front and rear direction. In the groove53m, the light reflecting parts Sr of the lower surfaces of the light guide members71and72are received. Surfaces of the grooves53mbecome reflecting surfaces capable of reflecting light toward the inner sides of the light guide members71and72.

As illustrated inFIG. 9, each of the first and second reflecting-side support parts53aand53bis formed at one end in the front and rear direction thereof with an engaging groove53i(FIG. 9illustrates only the engaging groove53iengaged with one claw part71c) engaged with each of the claw parts71cand72cof the light guide members71and72. The engaging groove53iis formed by cutting a part of an outside bank part53kextending in the front and rear direction. Each of the claw parts71cand72cof the light guide members71and72is engaged with the engaging groove53i, so that each of the light guide members71and72is restricted to be movable in the front and rear direction. The claw parts71cand72cof the light guide members71and72are formed at ends of sides at which the light sources61and62(seeFIG. 5) corresponding to the light guide members71and72are positioned. Consequently, when the light guide members71and are thermally expanded in the front and rear direction, distances between the light guide members71and72and the corresponding light sources61and62rarely changes. Consequently, it is possible to suppress a variation in the amount of light incident into the light guide members71and72from the light sources61and62.

Referring toFIG. 7, the front end support plate53dand the rear end support plate53eare disposed facing each other in the front and rear direction while interposing the first and second reflecting-side support parts53aand53btherebetween. As illustrated inFIG. 10, each of the end support plates53dand53e(FIG. 10illustrates only the end support plate53d) is formed with a pair of fitting holes53jfitted with each of the light guide members71and72. The front end part of each of the light guide members71and72is fitted in the pair of fitting holes53jof the front end support plate53dand is supported thereto. The rear end part of each of the light guide members71and72is fitted in the pair of fitting holes53jof the rear end support plate53eand is supported thereto. Each of the fitting holes53jis formed in a hat shape corresponding to the sectional shape of each of the light guide members71and72. The ends of each of the light guide members71and72are fitted in the fitting holes53j, so that they are non-rotatably restricted.

From each of the front end support plate53dand the rear end support plate53e, a columnar boss part53hprotrudes.FIG. 10toFIG. 12illustrate the boss part53hprotruding from the front end support plate53d. The boss part53his formed between the pair of fitting holes53jin each of the end support plates53dand53e. Each of the boss part53his formed with a screw hole53r(illustrated only inFIG. 12) having a predetermined depth toward a distal end side from a base end side. Each of the end support plates53dand53eis jointly fastened and fixed to the front side and rear side sheet metals80band80cby using a bolt65together with the LED boards63and64(FIG. 12illustrates only the LED board63). As illustrated inFIG. 11, from the outer side surface of each of the end support plates53dand53e, a pair of pins53pfor positioning with respect to the front side and rear side sheet metals80band80cprotrude. The front LED board63is mounted with the first light source61(seeFIG. 10) and the rear LED board64is mounted with the second light source62. The bolt65is screwed into the screw hole53rof the boss part53hby passing through the front side and rear side sheet metals80band80cand the LED boards63and64disposed overlappingly with the sheet metals80band80c(for example, seeFIG. 12).

Returning toFIG. 8, the illumination device40further includes a pair of inner pressing members81that press the inner ends of the first and second light guide members71and72to the support surfaces53sand53t, and a pair of outer pressing members82that press the outer ends of the first and second light guide members71and72to the support surfaces53sand53t.

The inner pressing members81are disposed at both right and left ends of the through hole53gformed in the flat plate53f. Lower ends of the inner pressing members81are engaged with and fixed to the bottom side sheet metal80aof the sheet metal member80. The inner pressing members81vertically extend from the bottom side sheet metal80a, are bent to an obliquely upper side toward an outer side in the right and left direction, and then are vertically bent up.

As enlarged and illustrated inFIG. 13, the outer pressing member82has a V-shaped part82a, a horizontal plate part82b, a vertical plate part82c, and an engaging claw82d. The V-shaped part82ais formed to be fitted into a connection part between the outer ends of the flat plate parts71band72band the light guide bodies71aand72aof the light guide members71and72(FIG. 13illustrates only the light guide member72). A base end of the V-shaped part82ais supported by the horizontal plate part82bin a cantilever shape, and the horizontal plate part82bis slightly bent to urge the V-shaped part82adownward. A base end of the horizontal plate part82bis engaged with and fixed to the left side sheet metal80dvia the vertical plate part82cand the engaging claw82d. The left side sheet metal80dis formed by cutting and raising a part of the sheet metal member80. The engaging claw82dprotrudes from an inner side surface of the vertical plate part82cand is engaged with an engaging hole80fof the left side sheet metal80d.

—Details of Division Structure of Support Member—

Next, the division structure of the support member53will be described with reference toFIG. 14toFIG. 17. The support member53is divided into the one side divided part531and the other side divided part532at a position closer to the rear end in the front and rear direction. The one side divided part531constitutes the rear end part of the support member53. A gap A is provided between the support surface53sof the one side divided part531and the support surface53tof the other side divided part532. The gap A extends in a direction (a perpendicular direction in the present embodiment) crossing the longitudinal direction of the light guide members71and72when viewed from the sides of the light guide members71and72. A dimension of the gap A is sufficiently larger than the amount of thermal expansion deformation of each of the divided parts531and532in the front and rear direction, which is caused by heat generation at the time of an image reading operation. That is, the gap A is set to a size enough for being able to absorb predicted thermal expansion deformation of each of the divided parts531and532in the front and rear direction.

From a right side end of the one side divided part531, a rectangular bracket plate part531cis formed to protrude. From the bracket plate part531c, a first protruding pin531aprotrudes. The first protruding pin531ahas a cylindrical shape and protrudes frontward from a front side surface of the bracket plate part531c. Furthermore, from a distal end surface (a front end surface) of the boss part53hof the one side divided part531, a second protruding pin531bprotrudes. The second protruding pin531bhas a cylindrical shape and protrudes frontward from the distal end surface of the boss part53h.

At the right side end of a rear end part of the other side divided part532, a first bracket plate part532cis vertically installed. The first bracket plate part532cis formed with a first engaging hole532along in the right and left direction. The first protruding pin531aof the one side divided part531is engaged with the first engaging hole532a. The first engaging hole532apermits only displacement of the first protruding pin531ain the right and left direction and the front and rear direction.

At the center of the rear end part of the other side divided part532in the right and left direction, a second bracket plate part532dis vertically installed. The second bracket plate part532dis formed with a second engaging hole532bslidably fitted with the second protruding pin531bof the one side divided part531. The second engaging hole532bpermits only displacement of the second protruding pin531bin the front and rear direction. The protruding pins531aand531band the engaging holes532aand532bare respectively engaged with each other, so that the one side divided part531and the other side divided part532are expandably connected to each other in the front and rear direction.

As illustrated inFIG. 15andFIG. 17, from a rear end surface of the other side divided part532, a first overlapped part532eand a second overlapped part532f(FIG. 17illustrates only the second overlapped part532f) protrude. The overlapped parts532eand532fare formed to enter under the reflecting-side support parts53aand53bof the one side divided part531. Upper surfaces of the overlapped parts532eand532fare inclined in parallel to the support surfaces53sand53tof the reflecting-side support parts53aand53b. A part of the upper surfaces532vand532wof the overlapped parts532eand532fis exposed to the sides of the light guide members71and72from the gap A (that is, is visible from the sides of the light guide members71and72). The upper surfaces532vand532wof the overlapped parts532eand532fbecome reflecting surfaces capable of reflecting light inside the light guide members71and72, similarly to the support surfaces53sand53t.

In the image reading device3configured as above, the support member53is divided into the one side divided part531and the other side divided part532in the front and rear direction (the longitudinal direction of the first and second light guide members71and72). Furthermore, the gap A is provided between the support surfaces53sand53tof the one side divided part531and the support surfaces53sand53tof the other side divided part532.

According to the configuration, even though the divided parts531and532are thermally expanded in the front and rear direction due to heat generation and the like of the light sources61and62, the gap A between both divided parts531and532is reduced, so that it is possible to absorb the thermal expansion deformation. Consequently, it is possible to prevent warping of the light guide members71and72due to a linear expansion difference between the support member53and the light guide members71and72. Thus, it is possible to reduce a variation in the amount of light, which is emitted from the light emitting part So of each of the light guide members71and72, depending on a position in the front and rear direction.

The support member53is mounted and fixed to the fixed sheet metal member80. Therefore, since thermal expansion deformation of the support member53in the front and rear direction is limited by the sheet metal member80, the support member53is easily warped up. As a consequence, the light guide members71and72supported to the support member53may be warped.

In contrast, in the present embodiment, thermal expansion deformation of the support member53in the front and rear direction is absorbed by the gap A, so that it is possible to prevent warping of the support member53and thus to prevent warping of the light guide members71and72.

Furthermore, in the present embodiment, the support surfaces53sand53tof the one side and the other side divided parts531and532become reflecting surfaces capable of reflecting light inside the light guide members71and72, adjacent parts of the one side divided part531and the other side divided part532overlap each other via the overlapped parts532eand532fprovided to the other side divided part532, and the upper surfaces532vand532w(surfaces exposed to the sides of the light guide members71and72through the gap A) of the overlapped parts532eand532fbecome reflecting surfaces capable of reflecting light.

According to the configuration, it is possible to prevent reduction of the amount of light emitted from positions of the light guide members71and72, which correspond to the gap A.

Furthermore, according to the present embodiment, the second protruding pin531bprotrudes from the one side divided part531, the second engaging hole532bis formed in the other side divided part532, and the second protruding pin531bis restricted to be movable in the second engaging hole532bonly in the front and rear direction (the longitudinal direction of the light guide members71and72). In this way, the one side divided part531and the other side divided part532can be connected to each other with a simple structure so as to be displaceable in the front and rear direction.

Furthermore, in the present embodiment, the light guide members71and72have the flat plate parts71band72bextending in the longitudinal direction thereof and the light guide bodies71aand72athat protrude from one side surface in the thickness direction of the flat plate parts71band72b, extend in the longitudinal direction, and have surfaces formed with the light emitting part So, and are formed such that their sectional shapes vertical to the longitudinal direction are hat shapes.

As described above, the light guide members71and72are formed to have a sectional hat shape, so that burr rarely occurs on the surfaces of the light guide members71and72at the time of molding. That is, in the related art, in a light guide member (for example, a columnar or polygonal prismatic light guide member) having no flat plate part, a molding method is employed to split a mold into a plurality of (for example, four) molds in a circumferential direction when viewed from the longitudinal direction of the light guide member and radially open/close each split mold in a radial direction. However, in this molding method, abutting surfaces of adjacent split molds may be rubbed with each other at the time of opening/closing and abraded. Therefore, there is a problem that burr easily occurs in a molded product in a boundary position of the split molds. In contrast, in the present embodiment, since the light guide members71and72are formed to have a sectional hat shape, a mold100for molding can be configured with a first mold101and a second mold102that are separated from each other and contacted with each other as illustrated inFIG. 18. Consequently, the molds do not slidably contact with each other at the time of opening/closing as described above. Thus, it is possible to suppress burr from occurring on the surfaces of the light guide members71and72that are molded products.

However, inventors have found a problem that when the sectional shape of the light guide member vertical to the longitudinal direction is a hat shape, both end parts in the longitudinal direction of the flat plate parts71band72bof the light guide members71and72are easily warped up to the sides of the light guide bodies71aand72a. That is, in a molded product using a general mold, a cooling speed of a part having a thin thickness is fast and a cooling speed of a part having a thick thickness is slow. Therefore, in the light guide members71and72having a sectional hat shape, the flat plate parts71band72bare cooled and then the light guide bodies71aand72aare cooled. A contraction amount of a material of a part slowly cooled is large due to an influence of a temperature difference between a surface and a center. Consequently, in this example, both end parts in the longitudinal direction of the flat plate parts71band72bare warped up by contraction force to an axial direction when the light guide bodies71aand72aare cooled.

When both end parts of the flat plate parts71band72bare warped up, since the light emitting parts So of the light guide members71and72are not parallel to the contact glass11, the illumination amount of light to a document surface may vary depending on the positions of the light guide members71and72in the longitudinal direction or light transmission by the light guide members71and72may be deteriorated.

In contrast, in the present embodiment, the support surfaces53sand53tof each of the light guide members71and72in the support member53(the one side and the other side divided parts531and532) abut the lower surfaces (surfaces opposite to the sides of the light guide bodies) of the flat plate parts71band72bof the light guide members71and72.

Consequently, displacement of the intermediate parts in the longitudinal direction of the light guide members71and72to a lower side is regulated by the support surfaces53sand53t. Thus, it is possible to suppress deformation of both end parts of each of the light guide members71and72such as warping up.

Moreover, in the present embodiment, the support member53is placed on the upper surface of the sheet metal member80(the bottom side sheet metal80a) fixed to the bottom wall part of the first moving carriage31. Furthermore, each of the light guide members71and72is pressed and fixed to each of the support surfaces53sand53tby the outer pressing members (seeFIG. 8) engaged with and fixed to the left side sheet metal80dof the sheet metal member80and the inner pressing members81engaged with and fixed to the bottom side sheet metal80aof the sheet metal member80.

According to this, displacement of each of the light guide members71and72to the light emitting part So side is regulated by the pressing members81and82. Consequently, it is possible to more reliably suppress deformation of both end parts of each of the light guide members71and72such as warping up.

Moreover, each of the pressing members81and82is provided over the whole of each of the light guide members71and72in the longitudinal direction. Consequently, both end parts of each of the light guide members71and72are further suppressed from being warped up.

Furthermore, the support member53abuts and is placed on the upper surface of the bottom side sheet metal80aof the fixed sheet metal member80. According to this, the support member53is placed on the firm metallic sheet metal member80, so that it is possible to improve support stiffness of each of the light guide members71and72by each of the support surfaces53sand53tof the support member53. Consequently, pressing force of each of the pressing members81and82is securely received by each of the support surfaces53sand53t, so that each of the light guide members71and72can be corrected in a straight shape with no warping.

OTHER EMBODIMENTS

In the aforementioned embodiment, an example, in which the support surfaces53sand53tof the support member53abut the lower surface of each of the light guide members71and72, has been described; however, the technology of the present disclosure is not limited thereto and a gap may exist between each of the support surfaces53sand53tand each of the light guide members71and72.

In the aforementioned embodiment, the overlapped parts532eand532fare formed at the other side divided part532; however, the technology of the present disclosure is not limited thereto and the overlapped parts532eand532fmay be formed at the one side divided part531.

In the aforementioned embodiment, the inner and outer pressing members81and82are fixed to the sheet metal member80; however, the technology of the present disclosure is not limited thereto and the inner and outer pressing members81and82may be fixed to the support member53.

In the aforementioned embodiment, an example, in which the light guide bodies71aand72ahave a semi-cylindrical shape, has been described; however, the technology of the present disclosure is not limited thereto and for example, the light guide bodies71aand72amay have a polygonal prismatic shape.

The technology of the present disclosure is available for an illumination device and an image reading device including the same, and particularly is available when it is applied to a copy machine, a printer, a multifunctional peripheral (MFP), a facsimile and the like.