JP2015122646A - Integrated scanning optical unit, image reading device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated scanning optical unit capable of efficiently cooling a circuit board on which a driving circuit driving a light source and a light-receiving part is mounted.SOLUTION: An image reading part 102 of an image forming apparatus 100 comprises a scanner cover part 201 including a contact glass 203, a scanner frame part 202, an integrated scanning optical unit 301 stored in the scanner frame part 202, a guide rod 302 as the moving means of the integrated scanning optical unit 301, a rail 303, or the like. The integrated scanning optical unit 301 comprises a light source 401, a reflection mirror 402, an image formation lens 403, a housing 404, and a circuit board 405 which is arranged outside the housing 404 and on which an image sensor 407 and an IC chip 408 are mounted. A flow path F through which an air flow passes is formed between the circuit board 405 and housing 404. The bottom edge of the board surface 405a of the circuit board 405 is projected from the housing 404.

Description

  The present invention relates to an optical system such as an illumination system, a reflecting mirror, and an imaging lens, an integrated scanning optical unit in which an image sensor such as a CCD is accommodated in a carriage case, and an image reading apparatus equipped with the integrated scanning optical unit, The present invention also relates to an image forming apparatus such as a digital copying machine, a scanner, and a facsimile provided with the image reading apparatus.

  2. Description of the Related Art Conventionally, image reading apparatuses represented by scanners are required to be downsized and high definition. In such a flow, an image reading apparatus called “integrated type” is a circuit in which an image sensor such as a CCD and a driving circuit such as an IC chip are mounted in addition to an optical system having a light source, a folding mirror, and an imaging lens. The substrate includes an “integrated scanning optical unit” integrally accommodated in the carriage case, which is advantageous in reducing the size of the image reading apparatus. However, as the drive circuit increases in speed and density, the amount of heat generated by the drive circuit increases. In such an “integrated” image reading apparatus, heat from the circuit board affects the optical system and the like. May give.

  As a technique for suppressing the influence of heat, a technique for cooling the entire integrated scanning unit with a fan (see, for example, Patent Document 1) is disclosed. Also, an air flow generated when an air flow passes through a vent hole when an integrated scanning unit in which a plurality of vent holes are formed in a substrate provided with a light source and an optical element is mounted reciprocates in the sub-scanning direction. There is also disclosed a technique for air-cooling a light source by using (see, for example, Patent Document 2).

  However, in the conventional technique using the fan of Patent Document 1, there is no disclosure about the cooling effect of the circuit board by the fan. Further, when a fan is used, dust resistance is important in order to prevent dust and dust from the outside air from adhering to the surface of the optical element and affecting the image quality. Moreover, in the prior art using the airflow described in Patent Document 2, the light source is cooled by air, and the circuit board that causes a large amount of heat generation is not cooled.

  The present invention has been made in view of the above circumstances, and provides an integrated scanning optical unit capable of efficiently cooling a circuit board on which a drive circuit for driving a light source and a light receiving unit is mounted. Objective.

  In order to achieve the above object, an integrated scanning optical unit according to the present application includes a light source that irradiates a document placed on a document table, a light receiving unit that receives reflected light from the document and reads an image, and a document. A light source, a circuit board on which a driving circuit for driving the light receiving part is mounted, a light source, a light receiving part, a reflecting part, and a circuit board are integrally held on the document table. A circuit board, and the circuit board is disposed with a gap on one side of the housing with the board surface facing in the moving direction of the housing, and between the board surface of the circuit board and the outer surface of the housing, A flow path through which an air flow flows is formed, and the board surface is projected from the housing in a direction intersecting with the moving direction.

  ADVANTAGE OF THE INVENTION According to this invention, the integrated scanning optical unit which can cool efficiently the circuit board which mounted the drive circuit which drives a light source and a light-receiving part can be obtained.

1 is a schematic diagram illustrating a configuration of an image forming apparatus according to Embodiment 1 of the present application. 1 is a schematic diagram illustrating a configuration of an image reading apparatus according to Embodiment 1 of the present application. 1 is a perspective view illustrating an internal configuration of an image reading apparatus according to Embodiment 1 of the present application. It is sectional drawing which shows the structure of the integrated scanning optical unit which concerns on Example 1 of this application. It is sectional drawing which shows the structure of the integrated scanning optical unit which concerns on Example 2 of this application. It is sectional drawing which shows the structure of the integrated scanning optical unit which concerns on Example 3 of this application. It is sectional drawing which shows the structure of the integrated scanning optical unit which concerns on a comparative example.

  Embodiments of an image forming apparatus including an integrated scanning optical unit according to the present application will be described below with reference to the drawings.

Example 1
The configuration of the image forming apparatus according to the first embodiment of the present application will be described with reference to FIGS. 1 and 2. Examples of the image forming apparatus include a copying machine, a facsimile machine, and a printing apparatus. As illustrated in FIG. 1, the image forming apparatus 100 according to the first exemplary embodiment includes an image forming unit 101, a paper supply device 40, and a document conveyance reading unit 104.

  The image forming apparatus 100 also includes a control unit (not shown) that controls the operation of each unit of the image forming unit 101, the paper supply device 40, and the document conveyance reading unit 104. The control unit includes a central processing unit (CPU) that controls the entire image forming apparatus 100, a read only memory (ROM) that stores various data and various programs, a random access memory (RAM), a hard disk drive (HDD), and the like. A storage unit and the like are provided. The CPU of the control unit reads and executes the program stored in the storage unit, whereby the process of the image forming apparatus is executed.

  The document conveying / reading unit 104 includes an image reading unit (image reading device of the present application) 102 fixed on the upper portion of the image forming unit 101, and an automatic document feeding unit (document conveying device supported by the image reading unit 102). Auto Document Feeder (hereinafter referred to as “ADF”) 103.

  The paper supply device 40 separates two paper feed cassettes 42 arranged in multiple stages in the paper bank 41, a feed roller 43 that feeds paper as a recording medium from the paper feed cassette 42, and the sent paper. A separation roller 45 and the like that are supplied to the paper feed path 44 are provided. In addition, the image forming apparatus 100 includes a plurality of transport rollers 46 that transport the paper to the paper feed path 37. With the paper supply device 40 having such a configuration, the paper in the paper feed cassette 42 is fed into the paper feed path 37 in the image forming apparatus 100.

  The image forming unit 101 forms an image on a recording medium based on the image information read by the image reading unit 102. The image forming unit 101 includes four process units 3K, 3Y, 3M, and 3C that form toner images of the optical writing device 2, K (black), Y (yellow), M (magenta), and C (cyan) colors. A transfer unit 24 having an intermediate transfer belt 25, a paper transport unit 28, a registration roller pair 33, a fixing device 34, a paper discharge roller pair 35, a switchback device 36, and a paper feed path 37. It becomes the composition of.

  In the image forming unit 101 having such a configuration, the process units 3K, 3Y, 3M, and 3C are driven by driving a light source (not shown) such as a laser diode and an LED disposed in the optical writing device 2. The laser beams are irradiated toward the photoconductors 4K, 4Y, 4M, and 4C. By this laser light irradiation, an electrostatic latent image is formed on the surface of the drum-shaped photoconductors 4K, 4Y, 4M, and 4C, and this electrostatic latent image is developed into a toner image through a predetermined development process. The The suffixes K, Y, M, and C added after the reference numerals in the drawings and description indicate black, yellow, magenta, and cyan. Therefore, the members with the subscripts K, Y, M, and C indicate the specifications for black, yellow, magenta, and cyan, respectively.

  In the image forming apparatus 100 configured as described above, the toner images formed on the surfaces of the photoreceptors 4K, 4Y, 4M, and 4C of the image forming unit 101 endlessly move in the clockwise direction as indicated by arrows in FIG. Primary transfer is performed on the intermediate transfer belt 25 in a superimposed manner. By this primary transfer, a four-color superimposed color toner image is formed on the intermediate transfer belt 25. Further, the paper supplied from the paper supply device 40 is sent out to the secondary transfer nip formed between the paper transport unit 28 and the intermediate transfer belt 25 by the registration roller pair 33 at a predetermined timing. By the secondary transfer nip, the color toner image on the intermediate transfer belt 25 is secondarily transferred to the sheet all at once.

  The sheet that has passed through the secondary transfer nip is separated from the intermediate transfer belt 25 and conveyed to the fixing device 34. The sheet conveyed to the fixing device 34 is fixed to the full color image by pressure or heating in the fixing device 34, then sent from the fixing device 34 to the paper discharge roller pair 35, and then discharged outside the apparatus. . The image forming unit 101 is not limited to the configuration of the electrophotographic system as shown in FIG.

  As shown in FIGS. 2 and 3, the image reading unit 102 arranged on the upper portion of the image forming unit 101 includes a scanner cover unit 201 that forms the upper surface of the image reading unit 102 as an accommodating unit (housing), and an image. And a scanner frame unit 202 that constitutes a side surface and a lower surface of the reading unit 102. The scanner cover unit 201 includes a contact glass 203 through which the document G passes or places the document G. The contact glass 203 is fixed to the scanner cover unit 201 so as to contact the document G.

  As shown in FIG. 3, an integrated scanning optical unit 301 that irradiates the original G with light and reads reflected light inside the image reading unit 102, and the integrated scanning optical unit 301 are arranged in the sub-scanning direction Y. And a driving means (not shown) such as a guide motor 302, a rail 303, and a stepping motor are provided. As shown in FIG. 1, the integrated scanning optical unit 301 is arranged directly below the contact glass 203 so as to be movable in the sub-scanning direction Y (left-right direction in FIG. 1). The integrated scanning optical unit 301 is a unit in which an image sensor such as an illumination, a reflection mirror, an imaging lens, and a CCD (details of which will be described later) are integrated as one unit, on a contact glass 203 as a document table. The image information of the original G is read. Image information read by the integrated scanning optical unit 301 is sent to the image forming unit 101.

  Details of the integrated scanning optical unit 301 according to the first embodiment of the present application will be described below with reference to FIG. As shown in FIG. 4, an integrated scanning optical unit 301 according to the first embodiment includes a light source 401, a reflection mirror 402 as a reflection unit, an imaging lens 403, a housing 404, and an image such as a CCD as a light receiving unit. And a circuit board 405 on which an IC chip 408 as a drive circuit (device) is mounted. The housing 404 integrally holds the circuit board 405 on which the light source 401, the reflection mirror 402, the imaging lens 403, the image sensor 407, and the IC chip 408 are mounted, and moves in the sub-scanning direction Y. The light source 401, the reflection mirror 402, and the imaging lens 403 are accommodated in the housing 404.

  The circuit board 405 is fixed to the outside of the side surface portion 404 a of the housing 404 by a bridge-shaped sheet metal 406 that extends between the circuit board 405 and the housing 404. At this time, the circuit board 405 is disposed so that the board surface 405 a of the circuit board 405 is oriented in the moving direction (sub-scanning direction) of the housing 404, and a gap is interposed between the board surface 405 a and the outer surface of the housing 404. To do.

  The light source 401 includes an LED or the like that irradiates light to the original G, and a plurality of light sources 401 are arranged at predetermined intervals in the main scanning direction X (direction passing through the paper surface of FIG. 4). A reflection mirror 402 as a reflection unit reflects the reflected light from the original G and guides it to an image sensor 407 as a light receiving unit. The imaging lens 403 focuses the reflected light from the reflection mirror 402 on the image sensor 407. The housing 404 is a housing that holds the light source 401, the reflection mirror 402, and the imaging lens 403 directly or indirectly.

  An image sensor 407 as a light receiving unit mounted on the circuit board 405 is composed of a photoelectric conversion element such as a CCD, and receives light reflected from the original G incident from the reflection mirror 402 and photoelectrically converts it. The IC chip 408 drives the image sensor 407 and the light source 401 and performs predetermined processing on the electrical signal photoelectrically converted by the image sensor 407.

  As shown in FIG. 4, the circuit board 405 has a board surface 405 a on which the image sensor 407 and the IC chip 408 are mounted, arranged vertically in the moving direction of the housing 404 (sub-scanning direction Y). Further, the circuit board 405 is arranged such that the center thereof is shifted downward in the vertical direction Z from the center of the housing 404. With this configuration, the lower part of the board surface 405 a of the circuit board 405 protrudes from the lower surface 404 b of the housing 404. Further, the upper end of the circuit board 405 is located below the upper end of the side surface portion 404a of the housing 404 (on the side opposite to the contact glass 203), and between the upper end of the circuit board 405 and the contact glass 203 will be described later. Compared with the comparative example, a wide gap is interposed.

  With such a configuration, when the integrated scanning optical unit 301 is scanned in the sub-scanning direction, the opening d1 between the lower part of the circuit board 405 and the housing 404 and the upper part of the circuit board 405 and the housing 404 are arranged. An air flow path F <b> 1 having the opening d <b> 2 as an inlet or an outlet is formed between the board surface 405 a of the circuit board 405 and the side surface portion 404 a of the housing 404. Further, the flow path F1 communicates with the flow path F2 formed between the lower surface 404b of the housing 404 and the surface of the scanner frame portion 202 on the opening d1 side, and the upper end of the circuit board 405 on the opening d2 side. It communicates with a flow path formed between the surface of the contact glass 203. Thus, the flow path F of the air flow composed of the flow paths F1, F2, and F3 is formed by the arrangement relationship between the scanner frame unit 202, the circuit board 405, and the housing 404.

  An image data reading operation by the image reading unit 102 having the integrated scanning optical unit 301 having the above configuration will be described. First, when reading the image data of the original G conveyed by the ADF 103, the integrated scanning optical unit 301 moves to the position A in FIG. In this stopped state, when the document G conveyed by the ADF 103 passes through the contact glass 203, light is emitted from the light source 401 toward the document G. The image sensor 407 reads the image data of the document G through the reflection mirror 402, the imaging lens 403, and the like while sequentially reflecting the light emitted from the light source 401 on the document surface (see FIG. 4 and the like above). .

  On the other hand, when reading the image data of the original G placed on the contact glass 203, a driving motor or the like is driven to move the integrated scanning optical unit 301 from the position A in FIG. Move in the right direction (sub-scanning direction) of the page. The integrated scanning optical unit 301 emits light from the light source 401 toward the document G while moving in the sub-scanning direction Y. The light emitted from the light source 401 is reflected by the original G placed on the contact glass 203, and the image of the original G is read by the image sensor 407 via the reflection mirror 402 and the imaging lens 403.

(Comparative example)
Here, an integrated scanning optical unit 301 ′ as a comparative example will be described with reference to FIG. The integrated scanning optical unit 301 ′ of the comparative example is different from the first embodiment in the mounting structure of the circuit board 405 ′. As shown in FIG. 7, the integrated scanning optical unit 301 ′ of the comparative example is accommodated in the scanner frame unit 202 ′ of the image reading unit 102 ′, and includes a light source 401 ′, a reflection mirror 402 ′, and an imaging lens 403. ', A housing 404', and an image sensor 407 'and a circuit board 405' on which an IC chip 408 'is surface-mounted.

  Also in this comparative example, the circuit board 405 ′ has the board surface 405a ′ arranged vertically in the sub-scanning direction Y, and is fixed to the outside of the side surface portion 404a ′ of the housing 404 ′ via a gap by a sheet metal 406 ′. . Here, the circuit board 405 of the first embodiment has a mounting structure in which the board surface 405a protrudes from the lower surface 404b of the housing 404 in the vertical direction Z. On the other hand, the circuit board 405 ′ of the comparative example is fixed substantially in the center of the side surface portion 404 a ′ of the housing 404 ′ in the vertical direction Z. The upper and lower ends of the circuit board 405 ′ are in the plane of the side surface 404 a ′ of the housing 404 ′, and the board surface 405 a ′ of the circuit board 405 ′ does not protrude from the housing 404 ′. Further, as described above, the integrated scanning optical unit 301 ′ is disposed immediately below the contact glass 203 ′. Therefore, the gap between the upper end of the circuit board 405 ′, which is substantially the same height as the upper end of the side surface portion 404a ′ of the housing 404 ′, and the contact glass 203 ′ is narrow, and the gap is hardly formed. .

(Cooling effect in Example 1, Comparative Example)
The cooling effect of the circuit boards 405 and 405 ′ when the integrated scanning optical unit 301 of the first embodiment configured as described above and the integrated scanning optical unit 301 ′ of the comparative example are scanned in the sub-scanning direction will be described. To do. First, when the image forming apparatus is operated, the portion that generates the most heat in the integrated scanning optical unit is in the vicinity of the IC chip, and this heat generation causes an optical system such as an IC chip, an image sensor, a light source, and an imaging lens. It will have an effect.

  When the comparative integrated scanning optical unit 301 ′ is scanned in the sub-scanning direction Y, as shown in FIG. 7, the space between the lower surface 404b ′ of the housing 404 ′ and the surface of the scanner frame portion 202 ′ flows. An air flow flows as the path F ′. Therefore, it is difficult for the air flow to flow into the gap between the housing 404 ′ and the circuit board 405 ′ that are orthogonal to the flow path F ′. Further, as described above, the distance between the circuit board 405 ′ and the contact glass 203 ′ is also narrow, and the air flow hardly flows between the circuit board 405 ′ and the side surface portion 404 a ′ of the housing 404 ′. For this reason, the heat generated in the vicinity of the IC chip 408 ′ is difficult to escape, which affects the optical system and the like. When the optical system is affected by heat, the positional relationship of the members of the optical system may change due to thermal expansion or the like, and the reflected light may not be guided well to the image sensor 407 '.

  On the other hand, in the integrated scanning optical unit 301 according to the first embodiment, the air flow in the scanner frame unit 202 flows along the flow path F when scanning is performed in the sub-scanning direction Y. Thereby, the heat of the circuit board 405 can be efficiently released and the heat dissipation can be improved. As a result, the influence of heat on the optical system or the like can be suppressed, and the reflected light can be satisfactorily read by the integrated scanning optical unit 301.

  More specifically, first, when the integrated scanning optical unit 301 is scanned in the right direction in FIG. 4 in the sub-scanning direction Y, the air flow in the scanner frame unit 202 causes the lower surface 404b of the housing 404 and the scanner frame unit to flow. Relatively flows in the flow path F2 between the surfaces of 202. The air flow that has flowed through the flow path F <b> 2 hits the board surface 405 a of the circuit board 405 protruding from the lower surface 404 b of the housing 404. Thereafter, the airflow flows in the direction of the opening d1 along the board surface 405a, and flows into the flow path F1 between the circuit board 405 and the housing 404 using the opening d1 as an inlet. The air flow flowing in the flow path F1 flows out to the flow path F3 side using the opening d2 as an outlet while exchanging heat with the circuit board 405, whereby the heat of the circuit board 405 is released.

  On the other hand, when the integrated scanning optical unit 301 is returned to the original position, that is, in the sub-scanning direction Y, it is moved from the right side to the left side in the drawing. By this movement, the air flow in the scanner frame 202 hits the side surface 404a of the housing 404 protruding from the upper end of the circuit board 405 via the flow path F3. The air flow that hits the side surface portion 404a flows in the direction of the opening d2 along the side surface portion 404a, and flows into the flow path F1 between the circuit board 405 and the housing 404 using the opening d1 as an inlet. The air flow that has passed through the flow path F <b> 1 flows into the flow path F <b> 2 using the opening d <b> 2 as an outlet while performing heat exchange with the circuit board 405, thereby releasing the heat of the circuit board 405.

  As described above, when the integrated scanning optical unit 301 is scanned in the sub-scanning direction, the air flow flows along the flow path F, so that the flow velocity of the air flow on the circuit board 405 is increased, and the heat dissipation performance. Will improve. In addition, when the original G is read by the ADF 103, the integrated scanning optical unit 301 is stopped without being scanned. Also at the time of this stop, since the flow path F functions as a flow path for natural convection, the heat dissipation in the circuit board 405 is improved. Therefore, the heat dissipation of the circuit board 405 can be improved without using a material with excellent heat dissipation or a member for heat dissipation.

  In addition, when the airflow flows through the flow path F, if the distance between the circuit board 405 and the lower portion of the scanner frame section 202 that is the housing portion is wide, a non-target flow path, for example, the lower end of the circuit board 405 A flow path is formed between the scanner frame unit 202 and the scanner frame unit 202. Then, since the air flow also flows on the flow path side, it is desirable that the distance between the circuit board 405 and the lower portion of the scanner frame portion 202 as a housing member is as short as possible. Thereby, an air flow becomes easy to flow smoothly into the flow path F1, and the heat dissipation of the circuit board 405 can be improved.

  As described above, in the image forming apparatus 100 including the integrated scanning optical unit 301 and the integrated scanning optical unit 301 according to the first embodiment of the present application, the circuit board 405 that generates a large amount of heat can be efficiently cooled. Therefore, the influence of heat on the optical system such as the IC chip 408, the image sensor 407, and the light source 401 can be reduced, and the image of the original G can be accurately read by the integrated scanning optical unit 301. As a result, the image forming apparatus 100 can perform image formation with excellent image quality.

  In addition, when dust entering from the outside adheres to the image sensor, it may not be possible to receive light at a place where the dust or the like has adhered. As a result, the reflected light from the original G cannot be guided to an image sensor such as a CCD, and there is a possibility that image data of a portion where a foreign substance exists may be lost or unclear. However, in the integrated scanning optical unit 301 according to the first embodiment, the air flow passes through the surface of the image sensor 407 along the flow path F, so that the effect of removing dust attached to the surface of the image sensor 407 is also achieved. I can expect. Accordingly, it is possible to read image data with high accuracy while suppressing loss of image data and the like, and to improve image quality.

(Example 2)
Next, an image reading apparatus (image reading unit) including an integrated scanning optical unit according to Example 2 of the present application will be described with reference to FIG. Of the members used in the second embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. The same applies to the following embodiments. As shown in FIG. 5, the integrated scanning optical unit 301 </ b> A according to the second embodiment is housed in the scanner frame unit 202 of the image reading unit 102, and includes a light source 401, a first reflecting mirror 402 a and a second reflecting mirror 402 a serving as a reflecting unit. A reflection mirror 402b, an imaging lens 403, a housing 404A, and an image sensor 407 as a light receiving unit and a circuit board 405 on which an IC chip 408 is surface-mounted are provided. The integrated scanning optical unit according to the second embodiment can also be applied to the image forming apparatus 100 according to the first embodiment.

  In the first embodiment, as shown in FIG. 4, only one reflecting mirror 402 is used. However, in the second embodiment, as shown in FIG. 5, two reflecting mirrors (first reflecting mirror 402a and A second reflecting mirror 402b) is used. As described above, the number and types of optical members such as the reflection mirror and the imaging lens of the optical system are appropriately changed in accordance with the size and purpose of use of the apparatus, the optical path of the reflected light guided to the image sensor 407, and the like. Can do.

  Also in the second embodiment, the circuit board 405 is arranged so that the board surface 405a protrudes from the housing 404A in the moving direction (sub-scanning direction), and an air flow strikes the board surface 405a. Further, the circuit board 405 is fixed to the outside of the side surface portion 404Aa of the housing 404A by a sheet metal 406 through a gap. Furthermore, in the second embodiment, the board surface 405a of the circuit board 405 is installed so as to be inclined with respect to the moving direction (sub-scanning direction). With such an inclined arrangement, the flow path F1 is also inclined with respect to the sub-scanning direction, and the flow velocity is less likely to decrease when the integrated scanning optical unit 301A moves in the sub-scanning direction.

  In the second embodiment, the side surface 404Aa of the housing 404A for fixing the circuit board 405 is also inclined so as to be parallel to the circuit board 405 in order to easily dispose the board surface 405a of the circuit board 405. It is said. With this configuration, the air flow smoothly flows in the flow path F1 between the side surface portion 404Aa of the housing 404A and the circuit board 405, and a decrease in the flow rate can be further suppressed. If the flow path F1 can be inclined with respect to the sub-scanning direction, it is not necessary to incline both the circuit board 405 and the side surface portion 404Aa of the housing 404A. Only the circuit board 405 may be inclined, or only the side surface 404Aa of the housing 404 may be inclined.

(Example 3)
Next, an image reading apparatus including an integrated scanning optical unit according to Example 3 of the present application will be described with reference to FIG. As illustrated in FIG. 6, the integrated scanning optical unit 301 </ b> B according to the third embodiment is housed in the scanner frame unit 202 of the image reading unit 102, and includes a light source 401, a reflection mirror 402 as a reflection unit, and an imaging lens. 403, a housing 404B, and a circuit board 405 on which an image sensor 407 as a light receiving unit and an IC chip 408 are surface-mounted. FIG. 6 shows an integrated scanning optical unit 301B positioned on one end side (initial position) A and an integrated scanning optical unit 301B positioned on the other end side (movement destination) B in the reciprocating movement in the sub-scanning direction Y. it's shown.

  In the third embodiment, as shown in FIG. 6, the other end side B of the movement destination of the integrated scanning optical unit 301 of the scanner frame unit 202, the side in the extending direction of the flow path F <b> 2 (the air flow destination). A fan member 502 is provided at the lower part of the wall surface (lower right of the paper surface in FIG. 6). The fan member 502 discharges the air in the scanner frame unit 202 to the outside, thereby forming an air flow in the flow path F (flow paths F2, F1, and F3). Promotes the flow of the flow. Furthermore, a plate-shaped shielding member 501 that separates the scanner frame 202 from the flow path F is installed in the scanner frame section 202 along the flow path F (F2). The shielding member 501 makes it difficult for the air flow formed by the fan member 502 to flow to the upper side of the scanner frame portion 202 and the like, and the structure easily flows in the flow path F (flow paths F2, F1, and F3). Become. Therefore, the air flow generated by the fan member 502 can be sent to the flow path F without loss. Even when the integrated scanning optical unit 301 moves to the other end B, the shielding member 501 is installed so that the integrated scanning optical unit 301 and the shielding member 501 do not contact each other. In the third embodiment, the fan member 502 is provided in the extending direction of the flow path F2. However, the present application is not limited to this, and the extending direction of the flow path F3, that is, the diagram of the scanner frame unit 202 is illustrated. 6 may be provided on the upper left wall surface. Also in this case, the air flow generated by the fan member 502 can be sent to the flow path F without loss.

  As described above, in the integrated scanning optical unit 301 </ b> B according to the third embodiment, an air flow is generated in the scanner frame unit 202 due to the exhaust force of the fan member 502. This air flow is guided by the shielding member 501 provided on the flow path F2 side, and directly flows into the flow path F from the flow path F3 to the flow paths F1 and F2. Therefore, the air flow generated by the fan member 502 can be sent to the flow path F without loss, and a high heat dissipation effect can be expected. Moreover, in the prior art, since the outside air is blown and cooled by the fan member, it is necessary to ensure the dustproof property against the dust from the outside. However, in the third embodiment, the fan member 502 is provided for the purpose of generating an air flow that flows through the flow path F by the exhaust gas, and further, the air flow flows on the surface of the circuit board 405, so that the image sensor. The adhesion of dust to 407 can be satisfactorily suppressed. Therefore, combined with the influence of heat, the image sensor 407 can read image data with high accuracy. As a result, the image quality in the image forming apparatus provided with the integrated scanning optical unit 301B can be improved.

  As mentioned above, although the Example and the modification of this invention were explained in full detail with drawing, each said Example is only the illustration of this invention, This invention is limited only to the structure of each said Example. It is not a thing. Needless to say, changes in design and the like within the scope of the present invention are included in the present invention.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 102 Image reading part (image reading apparatus)
201 Scanner cover part (accommodating part) 202 Scanner frame part (accommodating part)
203 Contact glass (original table) 401 Light source 402, 402a, 402b Reflection mirror 405 Circuit board 405a Board surface 404, 404A, 404B Housing 404a, 404Aa, 404Ba Side surface (one side)
407 Image sensor (light receiving unit)
408 IC chip (drive circuit) 501 Shield member 502 Fan member F, F1, F2, F3 Flow path G Document

JP 2004-266589 A JP2013-192051A

Claims (7)

A light source for illuminating the document placed on the document table;
A light receiving unit that receives reflected light from the document and reads an image;
A reflecting portion for guiding the reflected light from the document to the light receiving portion;
A circuit board on which a driving circuit for driving the light source and the light receiving unit is mounted;
The light source, the light receiving unit, the reflecting unit, and a housing that holds the circuit board together and reciprocates along the document table,
The circuit board is disposed on one side of the housing with a gap facing the board surface in the moving direction of the housing, and an air flow flows between the board surface of the circuit board and the outer surface of the housing. An integrated scanning optical unit characterized in that a flow path is formed and the board surface protrudes from the housing in a direction crossing the moving direction.   2. The integrated scanning according to claim 1, wherein at least one of the board surface of the circuit board forming the flow path and the outer surface of the housing is arranged to be inclined with respect to the moving direction. Optical unit. A light source for illuminating the document placed on the document table;
A light receiving unit that receives reflected light from the document and reads an image;
A reflecting portion for guiding the reflected light from the document to the light receiving portion;
A circuit board on which a driving circuit for driving the light source and the light receiving unit is mounted;
An integrated scanning optical unit comprising: the light source; the light receiving unit; the reflecting unit; and a housing that holds the circuit board integrally and reciprocates along the document table;
A housing for housing the integrated scanning optical unit; and
A moving means for reciprocally moving the integrated scanning optical unit relative to the original;
The circuit board is disposed on one side of the housing with a gap facing the board surface in the moving direction of the housing, and an air flow flows between the board surface of the circuit board and the outer surface of the housing. An image reading apparatus, wherein a flow path is formed and the board surface is projected from the housing in a direction crossing the moving direction.   The image reading apparatus according to claim 3, wherein at least one of the board surface of the circuit board forming the flow path and the outer surface of the housing is disposed to be inclined with respect to the moving direction. .   The image reading apparatus according to claim 3, wherein a fan member is provided in the housing portion in a flow direction of the air flow from the flow path.   The image reading apparatus according to claim 5, wherein a shielding member that separates the flow path and the inside of the housing portion is provided in the vicinity of the fan member along the flow path. The image reading apparatus according to any one of claims 3 to 6,
An image forming apparatus comprising: an image forming unit that forms an image on a recording medium based on image information read by the image reading apparatus.