JP2008102380A - Image reading apparatus and image forming apparatus having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reading apparatus capable of stably obtaining a high quality image by maintaining a constant distance between a manuscript face and point light sources arrayed on a light source substrate, thereby uniformizing the distribution of the illumination of the manuscript face. <P>SOLUTION: The image reading apparatus includes a light source 22 formed from the plurality of point light sources 30 arrayed on the light source substrate 31 in a main scanning direction, and reads the image of a manuscript by scanning the manuscript face by means of light emitted from the light source 22 to the manuscript face. In the image reader, the light source substrate 31 is mounted on an intermediate mounting member 33, and the intermediate mounting member 33 is positioned and fixed to the first scanning frame body 28 and a base mounting member 28A together with the light source substrate 31. In addition, the light source substrate 31 is positioned and fixed to the intermediate mounting member 33 with an adhesive. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image reading apparatus that scans an original with light from a plurality of point light sources arranged in the main scanning direction and reads an image with a photoelectric conversion element, and an image forming apparatus such as a copying machine, a printer, and a facsimile equipped with the image reading apparatus It is about.

  In an image forming apparatus such as a copying machine or a laser beam printer that employs an electrophotographic system, an image reading device that scans an original placed on a contact glass by optical scanning is provided. Based on the obtained image data, an image is formed on a recording material such as paper by an image forming means. Here, the image forming unit includes various process devices such as a photosensitive drum, a developing device, a transfer device, and a fixing device.

  Incidentally, the image reading apparatus further reflects the transparent contact glass on which the document is placed, the light source that emits light toward the document placed on the contact glass, and the reflected light reflected on the document surface. And a plurality of mirrors that change the direction of the light, a lens that collects the reflected light, and an electrical conversion element such as an optical CCD sensor that reads the reflected light collected by the lens.

As a light source of such an image forming apparatus, a point light source such as an LED is used. There have been proposals such as arranging point light sources having different light distribution characteristics, adjusting a current value supplied to the point light source, and narrowing the arrangement pitch of the point light sources toward the end.
JP 2004-177851 A

  However, Patent Document 1 does not clearly disclose a substrate mounting structure in which point light sources are arranged. When a point light source is used, the substrate on which the point light sources are arranged becomes elongated in the scanning direction, and there is a concern about warping of the substrate. In particular, when the point light source is turned on, heat is generated, and this heat causes the substrate to warp. If the substrate on which the point light sources are arranged is warped, the distance between the point light source and the document surface changes, resulting in a non-uniform illuminance distribution on the document surface, resulting in a reduction in image quality.

  The present invention has been made in view of the above problems, and an object thereof is to make the illuminance distribution uniform on the document surface while keeping the distance between the point light source arranged on the light source substrate and the document surface constant. Another object of the present invention is to provide an image reading apparatus capable of stably obtaining a high quality image and an image forming apparatus provided with the image reading apparatus.

  In order to achieve the above object, the invention described in claim 1 is provided with a light source in which a plurality of point light sources are arranged in a main scanning direction on a light source substrate, and the document is emitted by light emitted from the light source toward the document surface. In an image reading apparatus that scans a surface and reads a document image, the light source substrate is attached to an intermediate attachment member, and the intermediate attachment member is positioned and fixed to a scanning frame together with the light source substrate.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the light source board is attached to the intermediate attachment member after the position of the light source substrate is adjusted with a jig with respect to the intermediate attachment member.

  According to a third aspect of the present invention, there is provided a light source in which a plurality of point light sources are arranged in a main scanning direction on a light source substrate, and a document image is scanned by light emitted from the light source toward the document surface. In the image reading apparatus, the light source substrate is positioned and fixed to the attached member with an adhesive.

  The invention according to claim 4 is characterized in that, in the invention according to claim 3, the light source substrate is bonded to an intermediate mounting member with an adhesive, and the intermediate mounting member is positioned and fixed to the scanning frame together with the light source substrate. To do.

  The invention according to claim 5 is the invention according to claim 3 or 4, characterized in that any one of a photo-curing type, an ultraviolet curing type or a two-component mixed curing type adhesive is used as the adhesive.

  According to a sixth aspect of the present invention, there is provided a light source in which a plurality of point light sources are arranged on a light source substrate in a main scanning direction, and a document image is scanned by light emitted from the light source toward the document surface. In the image reading apparatus, the light source substrate is divided into a plurality of pieces in the longitudinal direction, and each divided piece is positioned and fixed to a member to be attached.

  The invention according to claim 7 is the invention according to claim 6, wherein each of the divided pieces of the light source substrate is attached to an intermediate attachment member, and the intermediate attachment member is positioned and fixed to the scanning frame together with the light source substrate.

  The invention described in claim 8 is characterized in that, in the invention described in claim 6 or 7, both ends in the longitudinal direction of each divided piece of the light source substrate are attached to a member to be attached.

  The invention according to claim 9 is the invention according to claim 6 or 7, wherein a portion between adjacent point light sources of each divided piece of the light source substrate is attached to a member to be attached.

  A tenth aspect of the invention includes the image reading apparatus according to any one of the first to ninth aspects and an image forming unit that forms an image on a recording material based on image data read by the image reading apparatus. The image forming apparatus is configured as described above.

  According to the first aspect of the present invention, since the intermediate mounting member is interposed between the light source substrate formed by arranging the point light sources and the substrate mounting member, the positional relationship between the light source substrate and the substrate mounting member is maintained with high accuracy. Therefore, the distance between the point light source arranged on the light source substrate and the original surface can be kept constant, and the illuminance distribution on the original surface can be made uniform, whereby a high quality image can be stably obtained.

  According to the second aspect of the present invention, since the position of the light source board is adjusted with respect to the intermediate mounting member with the jig and then the light source board is attached to the intermediate mounting member, the positional accuracy of the light source board to the intermediate mounting member is further improved. .

  According to the third and fifth aspects of the present invention, since the light source substrate is positioned and fixed to the member to be attached by the adhesive, even if the point light source is turned on and heat is generated, the heat is prevented from warping the substrate. The distance between the point light source and the original surface is kept constant, the illuminance distribution on the original surface becomes uniform, and a high-quality image can be stably obtained.

  According to invention of Claim 4 and 5, since the intermediate attachment member was interposed between the light source board | substrate and the board attachment member which were positioned and fixed to the to-be-attached member with the adhesive agent, between a light source board | substrate and a substrate attachment member The positional relationship can be maintained with high accuracy, the distance between the point light source arranged on the light source substrate and the original surface can be kept constant, and the illuminance distribution on the original surface can be made uniform, which stabilizes high-quality images. Can be obtained.

  According to the sixth aspect of the invention, the light source substrate is divided into a plurality of pieces in the longitudinal direction, and each divided piece is positioned and fixed to the attached member. The thermal expansion of each divided piece is kept small. Therefore, the warping of each divided piece is prevented, and as a result, the distance between the point light source and the original surface is kept constant, the illuminance distribution on the original surface becomes uniform, and a high-quality image can be stably obtained. .

  According to the invention described in claim 7, since the light source substrate is divided into a plurality of pieces in the longitudinal direction and each divided piece is fixed to the board mounting member, the warping of each divided piece is prevented and a high-quality image is stably displayed. In addition, since the intermediate mounting member is interposed between the light source substrate and the substrate mounting member, the positional relationship between the light source substrate and the substrate mounting member can be maintained with high accuracy.

  According to invention of Claim 8 or 9, since the site | part between the longitudinal direction both ends of each division | segmentation piece of a light source substrate or the adjacent point light source was attached to the to-be-attached member, generation | occurrence | production of curvature is suppressed, suppressing thermal expansion of each division | segmentation piece. Can be prevented, and the illuminance distribution on the document surface can be made uniform to stably obtain a high-quality image.

  According to the tenth aspect of the present invention, it is possible to stably obtain a high quality image based on image data read with high accuracy by the image reading apparatus.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[Image forming apparatus]
FIG. 1 is a front sectional view of a color copying machine as an embodiment of an image forming apparatus according to the present invention. The illustrated color copying machine includes an image reading device 20 according to the present invention at an upper portion of a main body 100, and the main body 100. The magenta image forming unit 1M, the cyan image forming unit 1C, the yellow image forming unit 1Y, and the black image forming unit 1BK constituting the image forming unit are arranged in a line at regular intervals in the inner central portion.

  The image forming units 1M, 1C, 1Y, and 1BK, which are image forming units, have drum type electrophotographic photosensitive members (hereinafter referred to as “photosensitive drums”) 2a, 2b, 2c, and 2d as image carriers. is set up. Around the photosensitive drums 2a to 2d, there are primary chargers 3a, 3b, 3c, 3d, developing devices 4a, 4b, 4c, 4d, transfer rollers 5a, 5b, 5c, 5d as primary transfer means, and drums. Cleaning devices 6a, 6b, 6c and 6d are arranged, respectively.

  The photosensitive drums 2a to 2d are drum-shaped amorphous silicon (α-Si) photosensitive members, and are rotated at a predetermined process speed in a direction indicated by an arrow (counterclockwise in FIG. 1) by a driving device (not shown). The

  The primary chargers 3a to 3d uniformly charge the surfaces of the photosensitive drums 2a to 2d to a predetermined potential by a charging bias applied from a charging bias power source (not shown).

  Further, the developing devices 4a to 4d contain magenta (M) toner, cyan (C) toner, yellow (Y) toner, and black (BK) toner, respectively, and are formed on the photosensitive drums 2a to 2d. The toner of each color is attached to each electrostatic latent image to develop each electrostatic latent image as a toner image of each color (visualization), and the toner is consumed and the developing devices 4a to 4d When a toner replenishment signal is issued because the remaining amount of toner is less than a certain value, toner of each color is replenished from the toner replenishing devices 7a, 7b, 7c and 7d to the developing devices 4a to 4d. The toner replenishing devices 7 a to 7 d are configured as cartridges that can be attached to and detached from the copying machine main body 100.

  The transfer rollers 5a to 5d as primary transfer means are arranged so as to be in contact with the photosensitive drums 2a to 2d via an endless intermediate transfer belt 8 at each primary transfer portion (primary transfer nip portion). ing. Here, the intermediate transfer belt 8 constitutes a second image carrier, and is stretched between the secondary transfer counter roller 9 and the tension roller 10 and travels to the upper surface side of each of the photosensitive drums 2a to 2d. Arranged to be possible. The secondary transfer counter roller 9 is disposed so as to be in contact with the secondary transfer roller 11 via the intermediate transfer belt 8 in the secondary transfer portion (secondary transfer nip portion). As the material of the intermediate transfer belt 8, for example, a dielectric resin such as polycarbonate, polyethylene terephthalate (PET), polyvinylidene fluoride (PVdF), or the like is selected. Although not shown, a belt cleaning device for removing residual toner remaining on the surface of the intermediate transfer belt 8 is installed outside the intermediate transfer belt 8 and in the vicinity of the tension roller 10. Yes.

  On the other hand, a laser scanner unit 40 is arranged below each image forming unit 1M, 1C, 1Y, 1BK inside the copying machine main body 100, and a paper feed cassette 50 is detachably installed at the bottom of the main body 100 below the image forming units 1M, 1C, 1Y, 1BK. In this paper feed cassette 50, a plurality of recording materials P are stacked and stored. In the vicinity of the paper feed cassette 50, a pickup roller 13 for feeding the recording material P from the paper feed cassette 50 to the transport path 12 one by one is provided.

  Further, the conveyance path 12 arranged in the vertical direction on one side of the copying machine main body 100 extends to a paper discharge tray 14 provided on the upper surface of the main body 100, and in the middle thereof, a pair of paper feed rollers 15. A registration roller pair 16, a fixing device 17 having a fixing roller 17a and a pressure roller 17b, and a paper discharge roller pair 18 are provided.

  Next, an image forming operation by the color copying machine having the above configuration will be described.

  When an image formation start signal is issued, the photosensitive drums 2a to 2d are driven to rotate in the direction of the arrow in FIG. 1 at a predetermined process speed in each of the image forming units 1M, 1C, 1Y, and 1BK, and these photosensitive drums 2a to 2d. Are uniformly charged positively by the primary chargers 3a to 3d. The laser scanner unit 40 emits a laser beam modulated by a color image signal for each color of the original image read by the image reading device 20 from a laser output unit 41, and the laser beam is emitted from a lens 42 and a plurality of mirrors. 43 and the lens 44, and are projected onto the surfaces of the photosensitive drums 2a to 2d, and electrostatic latent images corresponding to the color image signals of the respective colors are formed on the photosensitive drums 2a to 2d, respectively.

  First, magenta toner is adhered to the electrostatic latent image formed on the photosensitive drum 2a of the magenta image forming unit 1M by the developing device 4a to which a developing bias having the same polarity as the charged polarity of the photosensitive drum 2a is applied. The electrostatic latent image is visualized as a magenta toner image. The magenta toner image is rotationally driven in the direction indicated by the arrow in the primary transfer portion between the photosensitive drum 2a and the transfer roller 5a by the action of the transfer roller 5a to which a primary transfer bias having a polarity opposite to that of the toner is applied. Primary transfer is performed on the intermediate transfer belt 8.

  The intermediate transfer belt 8 on which the magenta toner image has been primarily transferred as described above moves to the next cyan image forming unit 1C. In the cyan image forming unit 1C as well, the cyan toner image formed on the photosensitive drum 2b is transferred onto the magenta toner image on the intermediate transfer belt 8 at the primary transfer portion in the same manner as described above.

  Similarly, the yellow and black toner images formed on the photosensitive drums 2c and 2d of the yellow and black image forming units 1Y and 1BK are respectively formed on the magenta and cyan toner images superimposed and transferred on the intermediate transfer belt 8. In each primary transfer portion, the images are sequentially overlapped, and a full-color toner image is formed on the intermediate transfer belt 8. The transfer residual toner that is not transferred onto the intermediate transfer belt 8 and remains on the photosensitive drums 2a to 2d is removed by the drum cleaning devices 6a to 6d, and is transferred by a waste toner transfer means (not shown) to be transferred to each toner. The toner is collected as waste toner in a toner collecting container formed integrally with the supply devices 7a to 7d.

  On the other hand, one sheet of recording material P is fed from the sheet feeding cassette 50 to the transport path 12 by the pickup roller 13 and the pair of sheet feeding rollers 15, and this recording material P is the leading edge of the full color toner image on the intermediate transfer belt 8. Is conveyed to the secondary transfer portion by the registration roller pair 16 in accordance with the timing of reaching the secondary transfer portion between the secondary transfer counter roller 9 and the secondary transfer roller 11.

  Then, a full color toner image is transferred to the intermediate transfer belt by the action of the transfer electric field formed by the secondary transfer roller 11 to which the secondary transfer bias having the opposite polarity to the toner is applied to the recording material P conveyed to the secondary transfer unit. The secondary transfer is performed on the recording material P from 8 at the same time.

  Thus, the recording material P onto which the full-color toner image has been transferred is subjected to charge removal processing and electrostatically separated from the intermediate transfer belt 8, and then conveyed to the fixing device 17. In the fixing device 17, a full-color toner image is heated and pressed at the fixing nip portion between the fixing roller 17 a and the pressure roller 17 b to be thermally fixed on the surface of the recording material P, and the toner image is fixed. A series of image forming operations is completed when the recording material P is discharged onto the discharge tray 14 by the discharge roller pair 18. The secondary transfer residual toner that is not transferred onto the recording material P but remains on the intermediate transfer belt 8 is removed by a belt cleaning device (not shown), and is transported by a waste toner transport means (not shown) to be shown. It is collected as waste toner in a collection container.

  Although the present invention has been described with respect to an embodiment in which the present invention is applied particularly to a color copying machine, the present invention is applicable to any other image forming apparatus such as a printer or a facsimile.

[Image reading device]
Next, details of the configuration of the image reading apparatus 20 according to the present invention will be described with reference to the accompanying drawings.

[First and second inventions]
2 is a front sectional view of the image reading apparatus according to the present invention, FIG. 3 is a plan view of the image reading apparatus, and the illustrated image reading apparatus 20 includes a transparent contact glass 21 on which an unillustrated document is placed. A light source 22 that emits light toward an image reading position X (see FIG. 2) for reading an image of the original G placed on the contact glass 21, and a reflected light reflected at the image reading position X is further reflected. A plurality of mirrors 23, 24, and 25 that change their directions, a lens 26 that collects the reflected light, and a CCD sensor 27 that is a photoelectric conversion element that reads the reflected light collected by the lens 26. It is configured. Here, the light source 22 and the mirror 23 are supported by a first scanning frame body 28, and the mirrors 24 and 25 are supported by a second scanning frame body, and these first and second scanning frame bodies. Reference numerals 28 and 29 optically scan the document G placed on the contact glass 21 by moving below the contact glass 21 in the left-right direction (sub-scanning direction) in FIGS.

  Thus, as shown in FIG. 3, the light source 22 is configured by arranging a plurality of point light sources 30 such as LEDs on an elongated light source substrate 31 at appropriate intervals in the main scanning direction (vertical direction in FIG. 3). However, an embodiment of the mounting structure will be described below.

<Embodiment 1>
4 is a side view of the first scanning frame showing the light source mounting structure according to Embodiment 1, and FIG. 5 is a view in the direction of arrow A in FIG.

  As shown in FIG. 4, in the first scanning frame 28, a board mounting member 28A that is long in the main scanning direction (perpendicular to the plane of FIG. 4) is formed obliquely by cutting and raising. Similarly, the reflector mounting member 28B is formed by cutting and raising at the facing position. A reflector 32 for condensing the light emitted from the light source at the image reading position X is attached to the reflector attachment member 28B.

  Incidentally, as shown in FIG. 5, a circular mounting hole 31a is formed at one end in the longitudinal direction of the light source substrate 31, and a long mounting hole 31b is formed at the other end in the longitudinal direction. Has been. A light source substrate 31 formed by arranging a plurality of point light sources 30 is attached to the substrate attachment member 28A by screws (not shown) that are inserted into attachment holes 31a and 31b formed at both ends in the longitudinal direction, and in the longitudinal direction. The intermediate portion is fixed to the board mounting member 28A by an adhesive. As the adhesive, a photo-curing type, an ultraviolet curing type or a two-component mixed curing type adhesive can be used. Moreover, the fixing location and the number of fixing points of the light source substrate 31 with the adhesive are arbitrary and are not particularly limited.

  As described above, in the present embodiment, both ends of the light source substrate 31 in the longitudinal direction are attached to the substrate attachment member 28A with screws, and the intermediate portion in the longitudinal direction of the light source substrate 31 is fixed to the substrate attachment member 28A with an adhesive. Even if the point light source 30 is turned on and heat is generated, the light source substrate 31 is prevented from being warped by this heat, the distance between the point light source 30 and the document surface is kept constant, and the illuminance distribution on the document surface becomes uniform. High quality images can be obtained stably.

  By the way, the light source substrate 31 does not need a length in the short direction considering only the function of arranging the point light sources 30, but it is long in the short direction when screwing an intermediate position in the long direction. The thickness (width) becomes large.

  However, in the present embodiment, since the intermediate portion in the longitudinal direction of the light source substrate 31 is fixed with the adhesive, the length (width) in the short direction of the light source substrate 31 can be minimized, and the image reading device 20 is used. Downsizing and unnecessary cost increase of the light source substrate 31 itself can be avoided.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS.

  6 is a side view of the first scanning frame showing the light source mounting structure according to the second embodiment, FIG. 7 is a view in the direction of arrow B in FIG. 6, and FIG. 8 is an attachment of the intermediate mounting member to the board mounting member. It is a side view which shows the point, In these figures, the same code | symbol is attached | subjected to the same element as what was shown in FIG.5 and FIG.6, and the description about them again is abbreviate | omitted below.

  In the present embodiment, a light source substrate 31 formed by arranging a plurality of point light sources 30 is attached to an intermediate attachment member 33, and the intermediate attachment member 33 is positioned together with the light source substrate 31 on a substrate attachment member 28A of the first scanning frame 28. It is fixed.

  That is, as shown in FIG. 7, long hole-shaped mounting holes 31 a and 31 b are formed at both ends in the longitudinal direction of the light source substrate 31, and a circular positioning hole 33 a is formed at one longitudinal end of the intermediate mounting member 33. An attachment hole 33b is formed, and an elongated positioning hole 33c and an attachment hole 33d are formed at the other end in the longitudinal direction. Further, as shown in FIG. 8, cylindrical positioning protrusions (half-pressed) 28a and screw holes 28b are formed at both ends in the longitudinal direction of the board mounting member 28A (both ends in the direction perpendicular to the paper surface of FIG. 8). Yes.

  Thus, the light source substrate 31 is attached to the intermediate attachment member 33 by screws (not shown) inserted through attachment holes 31a and 31b formed at both ends in the longitudinal direction. In this case, as in the first embodiment, the longitudinal intermediate portion of the light source substrate 31 may be fixed to the intermediate mounting member 33 with an adhesive (see FIG. 7).

  Next, the positioning projections 28a formed on the substrate mounting member 28A are fitted into the positioning holes 33a and 33c formed on both ends in the longitudinal direction of the intermediate mounting member 33 to which the light source substrate 31 is mounted, so that the intermediate mounting member 33 is mounted on the substrate. After positioning on the mounting member 28A, screws (not shown) inserted through the mounting holes 33b and 33d formed at both longitudinal ends of the intermediate mounting member 33 are screwed into the screw holes 28b formed in the board mounting member 28A. Thus, the intermediate attachment member 33 is positioned and fixed to the substrate attachment member 28 </ b> A together with the light source substrate 31.

  Here, since the intermediate mounting member 33 has the positioning holes 33a and 33c, the light source substrate 31 can be mounted on the intermediate mounting member 33 with high accuracy after the position of the light source substrate 31 is adjusted with a jig. it can. For example, the light source substrate 31 and the intermediate mounting member 33 can be held by a jig, and the position can be managed by the number of pulses of the motor. Or if the jig | tool which can light and position the point light source 30 and confirm light distribution is used, the positional accuracy to the intermediate attachment member 33 of the light source board | substrate 31 will be improved further. The positioning of the intermediate mounting member 33 with respect to the board mounting member 28A is not limited to the fitting of the positioning protrusions 28a into the positioning holes 33a and 33c. For example, a pin or the like is erected on the board mounting member 28A, You may employ | adopt the structure penetrated to the positioning hole formed in the attachment member 33. FIG.

  Thus, in the present embodiment, since the intermediate mounting member 33 is interposed between the light source substrate 31 in which the point light sources 30 are arranged and the substrate mounting member 28A, the position of the light source substrate 31 and the substrate mounting member 28A. The relationship can be maintained with high accuracy, the distance between the point light source 30 arranged on the light source substrate 31 and the original surface can be kept constant, and the illuminance distribution on the original surface can be made uniform. It can be obtained stably.

<Embodiment 3>
Next, a third embodiment of the present invention will be described with reference to FIGS.

  9 is a side view of the first scanning frame showing the light source mounting structure according to the third embodiment, FIG. 10 is a view in the direction of arrow C in FIG. 9, and FIG. 11 is a mounting of the intermediate mounting member to the board mounting member. It is a side view which shows the point, In these figures, the same code | symbol is attached | subjected to the same element as what was shown in FIGS. 6-8, and the description about them again is abbreviate | omitted below.

  In the present embodiment, a light source substrate 31 formed by arranging a plurality of point light sources 30 is attached to a substantially trapezoidal frame-like high-rigidity intermediate attachment member 34 without forming a cut and raised in the first scanning frame 28. The intermediate mounting member 34 is positioned and fixed on the flat surface of the first scanning frame 28 together with the light source substrate 31.

  That is, as shown in FIG. 10, long hole-shaped attachment holes 31a are formed at both ends in the longitudinal direction of the light source substrate 31, and as shown in FIG. 11, both flange portions 34A, 34B of the intermediate attachment member 34 are formed. A circular mounting hole 34a is formed at each of the three ends in the longitudinal direction and at the middle portion (only one flange portion 34a is shown in FIG. 11), and a long length is provided at both longitudinal ends of one flange portion 34B. A hole-like positioning hole 34b is formed (see FIG. 10). Further, as shown in FIG. 11, screw holes 28b are respectively formed at the three ends of the both ends in the longitudinal direction and the intermediate portion of the both ends in the width direction of the first scanning frame 28 (the left and right ends in FIG. 11). In addition, columnar positioning protrusions (half-pressed) 28a project from both ends in the longitudinal direction of one end in the width direction (the right end in FIG. 11).

  Thus, the light source substrate 31 is attached to the intermediate attachment member 34 by screws (not shown) inserted through attachment holes 31a formed at both ends in the longitudinal direction. In this case, as in the first embodiment, the longitudinal intermediate portion of the light source substrate 31 may be fixed to the intermediate mounting member 34 with an adhesive (see FIG. 10).

  Next, after positioning the positioning projections 28a formed on the first scanning frame body 28 in the positioning holes 34b formed at both ends in the longitudinal direction of the intermediate mounting member 34 to which the light source substrate 31 is mounted, the intermediate mounting member 34 is positioned. The intermediate mounting member 34 is screwed into the screw holes 28b formed in the first scanning frame body 28 by screwing screws 35 inserted into the mounting holes 34a formed at the three positions of both flange portions 34A and 34B of the mounting member 34. Are fixed to the first scanning frame 28 together with the light source substrate 31.

  Here, since the intermediate mounting member 34 has the positioning hole 34b, the intermediate mounting member 34 is adjusted after the position of the light source substrate 31 with respect to the intermediate mounting member 34 is adjusted by a jig, as in the second embodiment. Can be attached with high precision.

  Thus, in the present embodiment, as in the second embodiment, the intermediate mounting member 34 is interposed between the light source substrate 31 formed by arranging the point light sources 30 and the first scanning frame 28. The positional relationship between the light source substrate 31 and the first scanning frame 28 can be maintained with high accuracy, and the distance between the point light sources 30 arranged on the light source substrate 31 and the document surface is kept constant, and the illuminance distribution on the document surface. Can be made uniform, whereby a high-quality image can be stably obtained. In particular, in the present embodiment, the rigidity of the intermediate mounting member 34 is high, and the first scanning frame 28 is not cut and raised, so that the strength thereof can be increased.

[Third invention]
Next, an embodiment of the third invention will be described with reference to the accompanying drawings.

  FIG. 12 is a plan view of the image reading apparatus according to the third invention. As shown in FIG. 12, the present invention divides the light source substrate 31 into a plurality of pieces (three pieces in the illustrated example) in the longitudinal direction. The divided pieces 31-1, 31-2, 31-3 are positioned and fixed to the first scanning frame body 28 (substrate mounting member 28A) which is a mounted member. The other configuration of the image reading device 20 according to the present invention is the same as that of the image reading device 20 according to the first and second inventions. In FIG. 12, the same elements as those shown in FIG. The same reference numerals are given.

  Thus, as shown in FIG. 12, the light source 22 includes a plurality of (three in the illustrated example) point light sources 30 such as LEDs on the divided pieces 31-1, 31-2, 31-3 of the light source substrate 31. The main scanning direction (vertical direction in FIG. 12) is arranged at appropriate intervals. Hereinafter, an embodiment of the mounting structure will be described.

<Embodiment 1>
13 is a side view of the first frame body showing the light source mounting structure according to Embodiment 1 of the present invention, and FIGS. 14A and 14B are views in the direction of arrow D in FIG. In the figure, the same elements as those shown in FIGS. 4 and 5 are denoted by the same reference numerals.

  As shown in FIG. 13, a substrate mounting member 28A that is long in the main scanning direction (perpendicular to the plane of FIG. 13) is formed obliquely on the first scanning frame 28 by cutting and raising the substrate mounting member 28A. The light source substrate 31 is positioned and fixed.

  Here, as shown in FIGS. 14A and 14B, the light source substrate 31 is divided into three pieces in the longitudinal direction, and each of the divided pieces 31-1, 31-2, 31-3 is shown in FIG. 14 (a), it is fixed to the board mounting member 28A by screws (not shown) inserted through mounting holes 31a formed at both ends in the longitudinal direction, or adjacent to the board mounting member 28A as shown in FIG. 14 (b). It is fixed to the board mounting member 28A by a screw (not shown) inserted through a mounting hole 31a formed in the middle between the point light sources 30.

  Thus, in the present embodiment, the light source substrate 31 is divided into three pieces in the longitudinal direction, and the middle of the divided light sources 31-1, 31-2, 31-3 in the longitudinal direction or between the adjacent point light sources 30. Since this part is fixed to the board mounting member 28A, even if the point light source 30 is turned on and heat is generated, the thermal expansion of each of the divided pieces 31-1, 31-2, 31-3 due to this heat is suppressed to a small level. For this reason, warpage of each of the divided pieces 31-1, 31-2, 31-3 is prevented, and as a result, the distance between the point light source 30 and the original surface is kept constant, and the illuminance distribution on the original surface becomes uniform. High quality images can be obtained stably. If a minute gap is formed between the abutting portions of the adjacent divided pieces 31-1 and 31-2 and the divided pieces 31-2 and 31-3, the divided pieces 31-1, 31- The minute thermal expansion of 2,31-3 can be absorbed, and the warping of each of the divided pieces 31-1, 31-2, 31-3 can be more reliably prevented.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 15 is a side view of the first scanning frame showing the light source mounting structure according to Embodiment 2 of the present invention, and FIG. 16 is a view taken in the direction of arrow E in FIG. 15. The same elements as those shown in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted below.

  In the present embodiment, the divided pieces 31-1, 31-2, 31-3 of the light source substrate 31 divided into three in the longitudinal direction are attached to the intermediate attachment member 33, and the intermediate attachment member 33 is attached to the light source substrate 31. At the same time, it is characterized in that it is positioned and fixed to the substrate mounting member 28A of the first scanning frame 28.

  That is, as shown in FIG. 16, attachment holes 31 a are formed at both longitudinal ends of the divided pieces 31-1, 31-2, and 31-3 of the light source substrate 31, and the longitudinal direction of the intermediate attachment member 33. A circular hole-shaped positioning hole 33a and a mounting hole 33b are formed at one end, and a long hole-shaped positioning hole 33c and a mounting hole 33d are formed at the other end in the longitudinal direction. Although not shown, cylindrical positioning projections (half-pressed) and screw holes are formed at both ends in the longitudinal direction of the board mounting member 28A.

  Thus, each of the divided pieces 31-1, 31-2, 31-3 of the light source substrate 31 is respectively attached to the intermediate mounting member 33 by screws (not shown) inserted through mounting holes 31a formed at both ends in the longitudinal direction. It is attached.

  Next, the substrate mounting member 28A is formed in positioning holes 33a and 33c formed at both ends in the longitudinal direction of the intermediate mounting member 33 to which the divided pieces 31-1, 31-2 and 31-3 of the light source substrate 31 are mounted. After positioning by inserting the positioning protrusions (not shown), screws (not shown) that pass through the mounting holes 33b and 33d formed at both ends in the longitudinal direction of the intermediate mounting member 33 are formed on the board mounting member 28A. The intermediate mounting member 33 is positioned and fixed to the substrate mounting member 28A together with the light source substrate 31 by screwing into a screw hole (not shown).

  Here, since the intermediate mounting member 33 has the positioning holes 33a and 33c, the light source substrate 31 can be mounted on the intermediate mounting member 33 with high accuracy after the position of the light source substrate 31 is adjusted with a jig. it can. For example, the light source substrate 31 and the intermediate mounting member 33 can be held by a jig, and the position can be managed by the number of pulses of the motor. Or if the jig | tool which can light and position the point light source 30 and confirm light distribution is used, the positional accuracy to the intermediate attachment member 33 of the light source board | substrate 31 will be improved further. The positioning of the intermediate mounting member 33 with respect to the board mounting member 28A is not limited to the fitting of the positioning protrusions 28a into the positioning holes 33a and 33c. For example, a pin or the like is erected on the board mounting member 28A, You may employ | adopt the structure penetrated to the positioning hole formed in the attachment member 33. FIG.

  Thus, also in the present embodiment, the light source substrate 31 is divided into three in the longitudinal direction, and both axial ends of the divided pieces 31-1, 31-2, 31-3 are fixed to the intermediate mounting member 33. In addition to preventing warping of each of the divided pieces 31-1, 31-2, 31-3, a high quality image can be stably obtained, and an intermediate mounting member is provided between the light source substrate 31 and the substrate mounting member 28A. Since 33 is interposed, the positional relationship between the light source substrate 31 and the substrate mounting member 28A can be maintained with high accuracy.

<Embodiment 3>
Next, a third embodiment of the present invention will be described with reference to FIGS.

  FIG. 17 is a side view of the first scanning frame showing the light source mounting structure according to the third embodiment of the present invention, and FIG. 18 is a view in the direction of arrow F in FIG. The same elements as those shown in FIG. 10 are denoted by the same reference numerals, and description thereof will be omitted below.

  In the present embodiment, the divided pieces 31-1, 31-2, 31-3 of the light source substrate 31 divided into three pieces in the longitudinal direction are substantially omitted without forming a cut and raised in the first scanning frame 28. The intermediate mounting member 34 is attached to a trapezoidal frame-like high-rigidity intermediate mounting member 34, and the intermediate mounting member 34 is positioned and fixed to the flat surface of the first scanning frame body 28 together with the light source substrate 31.

  That is, as shown in FIG. 18, mounting holes 31a are formed at both ends in the longitudinal direction of the respective divided pieces 31-1, 31-2, 31-3 of the light source substrate 31, and one flange of the intermediate mounting member 34 is formed. Positioning holes 34b are formed at both ends in the longitudinal direction of the portion 34B. Although not shown, screw holes are formed in each of the three ends of the first scanning frame body 28 in the longitudinal direction at both ends in the width direction and at the middle portion, and at both ends in the longitudinal direction at one end in the width direction. Is provided with a cylindrical positioning projection (half-pressed).

  Thus, each of the divided pieces 31-1, 31-2, 31-3 of the light source substrate 31 is attached to the intermediate attachment member 34 by screws (not shown) inserted through attachment holes 31a formed at both ends in the longitudinal direction. It is done.

  Next, the first operation frame body 28 is formed in the positioning holes 34b formed at both ends in the longitudinal direction of the intermediate mounting member 34 to which the divided pieces 31-1, 31-2, 31-3 of the light source substrate 31 are mounted. The intermediate mounting member 34 is positioned with respect to the first scanning frame 28 by fitting the positioning protrusions (not shown), and the intermediate mounting member 34 is formed with three flanges 34A and 34B. The intermediate mounting member 34 is positioned and fixed to the first scanning frame body 28 together with the light source substrate 31 by screwing screws 35 inserted into the illustrated mounting holes into screw holes (not shown) formed in the first scanning frame body 28. .

  Here, since the intermediate mounting member 34 has the positioning hole 34b, the intermediate mounting member 34 is adjusted after the position of the light source substrate 31 with respect to the intermediate mounting member 34 is adjusted by a jig, as in the second embodiment. Can be attached with high precision.

  Thus, also in the present embodiment, as in the second embodiment, the light source substrate 31 is divided into three pieces in the longitudinal direction, and the axial directions of the divided pieces 31-1, 31-2, 31-3 are divided. Since both ends are fixed to the board mounting member 28, the split pieces 31-1, 31-2, 31-3 are prevented from warping and a high-quality image can be stably obtained. Since the intermediate mounting member 34 is interposed between the member 28 and the member 28, the positional relationship between the light source substrate 31 and the substrate mounting member 28 can be maintained with high accuracy. In the present embodiment, the rigidity of the intermediate mounting member 34 is high, and the first scanning frame body 28 is not cut and raised, so that the strength can be increased.

  In the above first to third embodiments, the light source substrate 31 is divided into three pieces in the longitudinal direction, but the number of divisions, the attachment position and the number of attachment points of each division piece can be arbitrarily set.

1 is a front sectional view of an image forming apparatus (color copying machine) according to the present invention. It is a front sectional view of the image reading apparatus according to the first and second inventions. It is a top view of the image reading apparatus which concerns on 1st and 2nd invention. It is a side view of the 1st scanning frame which shows the attachment structure of the light source which concerns on Embodiment 1 of 1st and 2nd invention. It is a figure of the arrow A direction of FIG. It is a side view of the 1st scanning frame which shows the attachment structure of the light source which concerns on Embodiment 2 of 1st and 2nd invention. It is a figure of the arrow B direction of FIG. It is a side view which shows the attachment point to the board | substrate attachment member of the intermediate attachment member in Embodiment 2 of 1st and 2nd invention. It is a side view of the 1st scanning frame which shows the attachment structure of the light source which concerns on Embodiment 3 of 1st and 2nd invention. It is a figure of the arrow C direction of FIG. It is a side view which shows the attachment point to the board | substrate attachment member of the intermediate attachment member in Embodiment 3 of 1st and 2nd invention. It is a top view of the image reading apparatus which concerns on 3rd invention. It is a side view of the 1st frame which shows the attachment structure of the light source which concerns on Embodiment 1 of 3rd invention. (A), (b) is a figure of the arrow D direction of FIG. It is a side view of the 1st scanning frame which shows the attachment structure of the light source which concerns on Embodiment 2 of 3rd invention. It is a figure of the arrow E direction of FIG. It is a side view of the 1st scanning frame which shows the attachment structure of the light source which concerns on Embodiment 3 of 3rd invention. It is a figure of the arrow F direction of FIG.

Explanation of symbols

1M, 1C, 1Y, 1BK Image forming unit (image forming means)
2a, 2b, 2c, 2d Photosensitive drums 3a, 3b, 3c, 3d Primary chargers 4a, 4b, 4c, 4d Development devices 5a, 5b, 5c, 5d Transfer rollers 6a, 6b, 6c, 6d Drum cleaning devices 7a, 7b , 7c, 7d Toner supply device 8 Intermediate transfer belt 9 Secondary transfer counter roller 10 Tension roller 11 Secondary transfer roller 12 Conveyance path 13 Pickup roller 14 Paper discharge tray 15 Paper feed roller pair 16 Registration roller pair 17 Fixing device 17a Fixing roller 17b Pressure roller 18 Discharge roller pair 20 Image reading device 21 Contact glass 22 Light source 23, 24, 25 Mirror 26 Lens 27 CCD sensor 28 First scanning frame 28A Substrate attachment member 28B Reflector attachment member 28a Positioning projection 28b Screw hole 29 Second scanning frame 30 Point light 31 Light source board 31-1 to 31-3 Split piece 31a, 31b Mounting hole 32 Reflector 33 Intermediate mounting member 33a, 33c Positioning hole 33b, 33d Mounting hole 34 Intermediate mounting member 34A, 34B Flange portion of intermediate mounting member 34a Mounting hole 34b Positioning hole 35 Screw 40 Laser scanner unit 50 Paper feed cassette 100 Copier body G Document X Image reading position

Claims (10)

In an image reading apparatus comprising a light source formed by arranging a plurality of point light sources on a light source substrate in a main scanning direction, and scanning a document surface with light emitted from the light source toward the document surface, and reading a document image,
An original reading apparatus, wherein the light source substrate is attached to an intermediate attachment member, and the intermediate attachment member is positioned and fixed to a scanning frame together with the light source substrate.   2. The image reading apparatus according to claim 1, wherein the light source substrate is attached to the intermediate attachment member after the position of the light source substrate is adjusted with a jig with respect to the intermediate attachment member. In an image reading apparatus comprising a light source formed by arranging a plurality of point light sources on a light source substrate in a main scanning direction, and scanning a document surface with light emitted from the light source toward the document surface, and reading a document image,
An image reading apparatus, wherein the light source substrate is positioned and fixed to an attached member with an adhesive.   4. The document reading apparatus according to claim 3, wherein the light source substrate is bonded to an intermediate mounting member with an adhesive, and the intermediate mounting member is positioned and fixed to the scanning frame together with the light source substrate.   5. The image reading apparatus according to claim 3, wherein any one of a photo-curing type, an ultraviolet curing type, and a two-component mixed curing type adhesive is used as the adhesive. In an image reading apparatus comprising a light source formed by arranging a plurality of point light sources on a light source substrate in a main scanning direction, and scanning a document surface with light emitted from the light source toward the document surface, and reading a document image,
An image reading apparatus, wherein the light source substrate is divided into a plurality of pieces in the longitudinal direction, and each divided piece is positioned and fixed to a member to be attached.   The image reading apparatus according to claim 6, wherein each divided piece of the light source substrate is attached to an intermediate attachment member, and the intermediate attachment member is positioned and fixed to the scanning frame together with the light source substrate.   8. The image reading apparatus according to claim 6, wherein both longitudinal ends of each divided piece of the light source substrate are attached to a member to be attached.   8. The image reading apparatus according to claim 6, wherein a portion between adjacent point light sources of each divided piece of the light source substrate is attached to a member to be attached.   An image forming apparatus comprising: the image reading apparatus according to claim 1; and an image forming unit that forms an image on a recording material based on image data read by the image reading apparatus. .

Images