JP5516186B2 - Optical scanning apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an optical scanning device and an image forming apparatus.

  The optical system noise shielding structure of Patent Document 1 is an optical system having an electronic component that is a source of radio noise, and the electronic component that is a source of radio noise is covered with a shield casing and is formed in the shield casing. The opened opening has a cylindrical structure to suppress the propagation of high frequency corresponding to radio noise.

  In the optical scanning device of Patent Document 2, the semiconductor laser and the circuit board are covered and sealed with a conductive optical box and a holding member to prevent leakage of unnecessary radio waves.

JP 08-032762 JP 2000-249957

  The present invention provides an optical scanning device and an image forming apparatus capable of suppressing radio wave leakage from a drive substrate or radio wave leakage to a drive substrate in a configuration in which a light source drive substrate is provided outside an optical box. With the goal.

Optical scanning device according to claim 1 of the present invention includes a light source for emitting a light attached to the outside of the optical box, is provided inside the optical box, one light incident from the light source on the object to be irradiated a scanning means for scanning in a direction, with mounting surface on which an electronic component for driving at least said light source is mounted is disposed opposite at least the optical box side, a site different from the outside of the light source of the optical box mounted on a driving substrate of multiple layers to emit light by driving the light source, the first radio wave cutoff means for cutting off radio waves vignetting mounted on the outside of the optical box so as to cover the mounting surface of the drive substrate And a second radio wave blocking means for blocking radio waves, which is formed so as to cover at least a mounting range of an electronic component that drives the light source, in at least one layer of the driving substrate.

  The optical scanning device according to claim 2 of the present invention is provided with a plurality of light sources and a plurality of electronic components that drive the light sources, and a distance between the light sources and the electronic components that drive the light sources is greater than a plurality of intervals between the light sources. And the second radio wave blocking means covers between the light source and the electronic component that drives the light source.

  In the optical scanning device according to a third aspect of the present invention, the drive substrate has a plurality of layers of three or more layers, and the second radio wave blocking means is formed in an intermediate layer.

  According to a fourth aspect of the present invention, in the optical scanning device, the drive substrate includes an iron substrate as the second radio wave blocking means.

  According to a fifth aspect of the present invention, there is provided an image forming apparatus that is rotatably provided and has a charged member whose outer periphery is charged, and forms a latent image by irradiating light to the charged outer periphery of the charged member. 5. The optical scanning device according to claim 1, a developer image forming unit that forms a developer image by developing a latent image on an outer periphery of the member to be charged with a developer, and the developer A transfer unit that transfers the developer image formed by the image forming unit to a recording medium; and a fixing unit that fixes the developer image transferred by the transfer unit onto the recording medium.

  According to the first aspect of the present invention, in the configuration in which the drive substrate of the light source is provided outside the optical box, the leakage of the radio wave from the drive substrate or the drive substrate is compared with the configuration in which the radio substrate side of the drive substrate is not provided It is possible to suppress radio wave leakage to the.

  According to the second aspect of the present invention, radio waves generated between the light source and the electronic component can be suppressed as compared with a configuration in which the distance between the light source and the electronic component that drives the light source is longer than the interval between the plurality of light sources.

  According to the invention of claim 3, an electronic component different from the electronic component for driving the light source can be mounted on the surface opposite to the mounting surface side of the drive substrate.

  In the invention of claim 4, it is not necessary to separately provide the second radio wave blocking means.

  According to the fifth aspect of the present invention, radio wave leakage to the optical box side provided in the image forming apparatus can be suppressed as compared with the configuration in which the second radio wave blocking means is not provided.

1 is an overall view of an image forming apparatus according to a first embodiment of the present invention. 1 is a plan view showing an optical system of an optical scanning device according to a first embodiment of the present invention. 1 is a perspective view illustrating an appearance of an optical scanning device according to a first embodiment of the present invention. It is the side view which looked at the optical scanning device concerning a 1st embodiment of the present invention from the shield box side. It is sectional drawing which shows the attachment state to the optical box of the light source drive substrate which concerns on 1st Embodiment of this invention. It is sectional drawing which showed typically the layer structure of the light source drive substrate which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows the 2nd layer of the light source drive board | substrate which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows the electromagnetic wave interruption | blocking state of the light source drive board | substrate which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the attachment state to the optical box of the light source drive substrate which concerns on 2nd Embodiment of this invention.

  An example of the optical scanning device and the image forming apparatus according to the first embodiment of the present invention will be described.

  FIG. 1 shows an image forming apparatus 10 as an example of the first embodiment. The image forming apparatus 10 includes a housing 10A that constitutes a main body. The housing 10A includes an image processing unit that performs image processing on input image data, and the image forming apparatus 10. A control unit 12 that controls the operation of each unit is provided. Further, an optical scanning device 20 that performs optical scanning (exposure) with laser light L (LY, LM, LC, LK) is provided in the center of the housing 10A. An arrow V indicates the vertical direction, and an arrow H indicates the horizontal direction.

  The image processing unit of the control unit 12 processes image data input from an external device into gradation data of four colors of yellow (Y), magenta (M), cyan (C), and black (K). The processed gradation data is sent to the optical scanning device 20. Details of the optical scanning device 20 will be described later. In the following, when it is necessary to distinguish between four colors Y, M, C, and K, description is given with Y, M, C, and K added to the reference, and when there is no need to distinguish and explain. , Y, M, C, K are omitted.

  Above the optical scanning device 20, there are irradiated bodies that are formed in a cylindrical shape and are driven to rotate in the direction of the arrow (clockwise direction in the figure), and photoreceptors 14Y, 14M, 14C, and 14K as examples of charged members, The charging rollers 16Y, 16M, 16C, and 16K that charge the outer peripheral surfaces of the photoconductors 14Y, 14M, 14C, and 14K, and the optical scanning device 20 on the outer peripheral surfaces of the charged photoconductors 14Y, 14M, 14C, and 14K are laser light L. Of the developer image forming means that develops the electrostatic latent image formed by irradiating (exposure) with toners (developer) of Y, M, C, and K and visualizes them as a toner image (developer image). As an example, developing units 18Y, 18M, 18C, and 18K and a cleaning unit 22 that cleans the outer peripheral surface of the photoconductor 14 after the toner image is transferred to an intermediate transfer belt 32 described later are spaced apart in the direction of arrow H. It is arranged to have. Note that only the cleaning unit 22 corresponding to Y is given a reference numeral, and the reference numerals of the cleaning units 22 corresponding to M, C, and K are omitted.

  The charging roll 16 is driven to rotate as the photosensitive member 14 is driven to rotate by a driving unit (not shown), and is applied with a voltage by a voltage applying unit (not shown) including a power source. The outer peripheral surface of the photoreceptor 14 is charged (for example, charged to the same polarity as the toner) by the discharge due to the potential difference between them. The cleaning unit 22 is configured to scrape and collect the toner remaining on the outer peripheral surface of the photoconductor 14 with a blade (reference numeral omitted) that contacts the outer peripheral surface of the photoconductor 14.

  Since the developing units 18Y, 18M, 18C, and 18K are configured in the same manner, the developing unit 18Y will be described here, and the display and description of the reference numerals of the constituent members of the developing units 18M, 18C, and 18K will be omitted. The developing unit 18 </ b> Y has a housing 24 that contains toner, a developing roll 26 in the housing 24, a supply auger 28 that rotates and supplies the toner to the developing roll 26, and rotates in the housing 24. A stirring auger 29 for stirring the toner is provided. In the case of a two-component system using a developer having a carrier, the developing roll 26 is composed of a rotating developing sleeve and a plurality of magnetic pole forming members (not shown) fixed inside the developing sleeve, and only the toner is used. In the case of the one-component system as a component, it is composed of a rubber roll that adheres toner to the outer peripheral surface by frictional charging.

  On the other hand, a primary transfer unit 30 is provided above each of the photoconductors 14Y, 14M, 14C, and 14K as an example of a transfer unit that primarily transfers the toner image on the outer peripheral surface of the photoconductor 14. The primary transfer unit 30 includes an endless intermediate transfer belt 32, a driving roll 34 that is wound around the intermediate transfer belt 32 and rotates to rotate the intermediate transfer belt 32 in an arrow direction (counterclockwise direction in the drawing). , An auxiliary roll 35 provided around the intermediate transfer belt 32 so as to be rotatable on the side opposite to the drive roll 34 in the direction of arrow H, and an intermediate transfer at a position adjacent to the auxiliary roll 35 around which the intermediate transfer belt 32 is wound. A tension applying roll 36 that applies tension to the belt 32, a cleaning unit 38 that cleans the outer peripheral surface of the intermediate transfer belt 32, and the photoconductors 14Y, 14M, 14C, and 14K across the intermediate transfer belt 32 are disposed. Primary transfer rolls 42Y, 42M, 42C, and 42K.

  In the primary transfer unit 30, the four primary transfer rolls 42 </ b> Y, 42 </ b> M, 42 </ b> C, and 42 </ b> K are energized (energized with a polarity opposite to the polarity of the toner) by energizing means (not shown). The formed yellow (Y), magenta (M), cyan (C), and black (K) toner images are transferred onto the intermediate transfer belt 32 in a multiple manner.

  Further, the toner image on the intermediate transfer belt 32 is secondarily transferred to the recording paper P (recording medium) by being energized by energizing means (not shown) on the opposite side of the auxiliary roll 35 with the intermediate transfer belt 32 in between. A secondary transfer roll 44 is provided as an example of the transfer means. Further, a sheet conveyance path 46 for conveying the recording sheet P is provided above and below a portion (secondary transfer position) where the intermediate transfer belt 32 is sandwiched between the auxiliary roll 35 and the secondary transfer roll 44. The yellow (Y), magenta (M), cyan (C), and black (K) toner images transferred onto the intermediate transfer belt 32 in a multiple manner are transported to the secondary transfer position, and the paper transport path. Secondary transfer is performed on the recording paper P conveyed along the line 46.

  On the other hand, on the lower side in the housing 10 </ b> A and on the upstream side in the transport direction of the paper transport path 46, a storage unit 50 for storing the recording paper P is provided. The accommodating portion 50 is provided with a paper feed roll 52 and a separation roll 54 above the end on the paper conveyance path 46 side. The paper feed roll 52 is driven to rotate by a motor (not shown) so as to feed the recording paper P stacked in the accommodating portion 50 to the paper transport path 46, and the separation roll 54 is a paper feed roll. The recording paper P sent out at 52 is separated and conveyed one by one.

  On the paper conveyance path 46, on the downstream side of the separation roll 54, an alignment roll 56 for adjusting the conveyance timing of the recording paper P to the secondary transfer position is provided. As a result, the recording paper P supplied (conveyed) from the storage unit 50 to the paper conveyance path 46 is sent out to the secondary transfer position by the alignment roll 56 that rotates at a predetermined timing. A fixing device 60 for fixing the toner image transferred onto the recording paper P to the recording paper P is provided on the paper conveyance path 46 downstream of the secondary transfer position.

  The fixing device 60 includes a fixing roll 62 that has a heat source therein and is rotationally driven, and a pressure roll 64 that pressurizes the recording paper P toward the fixing roll 62. In the fixing device 60, the toner image on the recording paper P is melted by the heat of the fixing roll 62 and is fixed on the recording paper P by the pressure of the pressure roll 64. In addition, on the downstream side of the fixing device 60 on the paper conveyance path 46, a discharge roll 66 for discharging the recording paper P on which the toner image is fixed to a discharge portion 68 provided at the upper part of the housing 10A is provided. Yes.

  In the housing 10A, Y, M, C, and K toners supplied to the developing units 18Y, 18M, 18C, and 18K are placed at positions above the intermediate transfer belt 32 and below the discharge unit 68, respectively. The accommodated toner cartridges 19Y, 19M, 19C, and 19K are provided side by side in the arrow H direction. The toner cartridges 19Y, 19M, 19C, and 19K are connected to the housings 24 through toner supply means (not shown) such as an auger, and the toner is supplied into the housings 24 by the operation of the toner supply means. It has become so.

  Next, an image forming process of the image forming apparatus 10 will be described.

  First, gradation data of each color is sequentially output from the image processing unit in the control unit 12 to the optical scanning device 20. Subsequently, the laser beams LY, LM, LC, and LK emitted and scanned in accordance with the gradation data from the optical scanning device 20 are irradiated (exposed) on the outer peripheral surface of the photoreceptor 14 charged by the charging roll 16, and An electrostatic latent image is formed on the outer peripheral surface of the photoreceptor 14. Further, the electrostatic latent image formed on the photoconductor 14 is developed by developing units 18Y, 18M, 18C, and 18K, and each of yellow (Y), magenta (M), cyan (C), and black (K) is developed. It is visualized as a toner image of each color.

  Subsequently, the yellow (Y), magenta (M), cyan (C), and black (K) toner images formed on the respective photoreceptors 14 are circulated on the intermediate transfer belt 32 by the primary transfer roll 42. Is transcribed in multiple. Here, the recording paper P is conveyed by the paper feed roll 52, the separation roll 54, and the alignment roll 56 from the storage unit 50 to the secondary transfer position of the paper conveyance path 46 at a predetermined timing. The color toner images on the intermediate transfer belt 32 are secondarily transferred onto the recording paper P by the secondary transfer roll 44.

  Subsequently, the recording paper P on which the toner image is transferred is conveyed to the fixing device 60. In the fixing device 60, the toner image on the recording paper P is fixed on the recording paper P by being heated and pressed by the fixing roll 62 and the pressure roll 64. Then, the recording paper P after fixing is discharged by the discharge roll 66 to the discharge portion 68 on the housing 10A.

  Next, the optical system of the optical scanning device 20 will be described.

  As shown in FIG. 1, the optical scanning device 20 includes a box main body 72 as an example of an optical box, and laser light LY, LM, LC attached to the box main body 72 based on gradation data of Y, M, C, K. Semiconductor lasers 74Y, 74M, 74C, and 74K as examples of light sources that emit LK, and polygon mirrors as an example of scanning means that deflects and scans the laser beams LY, LM, LC, and LK emitted from the semiconductor lasers 74 75 (rotating polygon mirror) and the direction of the laser light LY, LM, LC, LK accommodated in the box main body 72 and emitted from each semiconductor laser 74 according to the arrangement position of the photoreceptors 14Y, 14M, 14C, 14K The first optical system 70 and the second optical system 80 that reflect or transmit light are included. In FIG. 1, illustration of some optical components of the first optical system 70 is omitted.

  As shown in FIG. 2, the first optical system 70 includes a collimator lens 76, a slit 77, and a first reflection arranged in order on the optical path between each semiconductor laser 74 and the polygon mirror 75 (the front stage of the polygon mirror 75). A mirror 78, a first lens system 79, a second reflection mirror 81, a third reflection mirror 82, a second lens system 83, and a first fθ lens 84 and a second fθ lens arranged in this order on the optical path downstream of the polygon mirror 75. 85 and a folding mirror 86.

  As shown in FIG. 1, the second optical system 80 includes a light separating polygon mirror 88 that separates the laser beams LY, LM, LC, and LK reflected by the folding mirror 86, and a laser separated by the light separating polygon mirror 88. The fourth reflection mirrors 89Y, 89M, 89C, 89K that reflect the light LY, LM, LC, LK and the laser beams LY, LM, LC, LK reflected by the fourth reflection mirrors 89Y, 89M, 89C, 89K are exposed. It includes a final mirror 91Y, 91M, 91C, 91K that reflects toward the bodies 14Y, 14M, 14C, 14K.

  As shown in FIG. 2, the second optical system 80 includes a reflection mirror 96 that reflects a part of the laser light L (for example, LK) that has passed through the light separating polygonal mirror 88, and a laser beam that is reflected by the reflection mirror 96. It has the condensing lens 97 which condenses L, and the optical sensor 98 into which the laser beam L condensed with the condensing lens 97 injects. The optical sensor 98 is composed of a photodiode or the like. The optical sensor 98 includes a laser beam that advances to the scanning start position each time the laser beam L scans the photosensitive member 14 (see FIG. 1) in the axial direction. L is incident. That is, the optical sensor 98 detects the scanning start timing when the photosensitive member 14 is scanned by the laser light L, and the optical scanning device 20 adjusts the writing start timing of each color.

  Next, the attachment structure of each member of the optical scanning device 20 will be described.

  FIG. 3 shows the appearance of the optical scanning device 20. The upper opening (not shown) of the box main body 72 is covered with a lid body 102, and four glass windows that allow the laser light LY, LM, LC, and LK (see FIG. 1) to pass through the lid body 102. 104 is provided. The box main body 72 and the lid 102 are made of, for example, a polyethylene terephthalate-based or polycarbonate-based glass fiber reinforced resin. A side wall 93B described later is located on the front side of the image forming apparatus 10 (see FIG. 1).

  The box main body 72 is provided at the four corners of the box main body 72, the bottom wall 92 having a rectangular shape in plan view supporting each optical system, the side walls 93A, 93B, 93C, and 93D formed on the four sides of the bottom wall 92. And four seats 94 fixed to the frame 25 formed in the housing 10A (see FIG. 1). The seat portion 94 is provided with a seat plate 94A at a portion in contact with the frame 25, and an attachment hole 94B is formed so as to penetrate the seat plate 94A. And the seat part 94 is attached to the frame 25 via the attachment hole 94B with a screw N1 (see FIG. 2). The frame 25 is made of a metal such as aluminum or stainless steel and is grounded.

  On the side wall 93A of the box main body 72, an example of a light source driving substrate 110 for driving the semiconductor lasers 74Y, 74M, 74C, and 74K, and a first radio wave blocking unit that blocks electromagnetic waves (radio waves) generated by the light source driving substrate 110. A shield box 120 is attached. The shield box 120 is formed, for example, by bending a metal plate such as aluminum, copper, or stainless steel. The shield box 120 may be formed of a plastic containing a conductive filler such as a carbon filler or a metal filler, a plastic coated with a conductive paint, or the like.

  The shield box 120 includes a main wall 121, a top wall 122 provided above the main wall 121, side walls 123 provided on the left and right sides of the main wall 121, and a part (lower part) of each side wall 123. And a seat portion 125 formed by bending a portion projecting downward from the left and right ends of the lower end of the main wall 121. The main wall 121 has a through hole 126 for passing the screw N2 through the mounting hole 124A of the seat portion 124, and a through hole for connecting an external connector to the connectors 127A, 127B, and 127C provided on the light source driving board 110. Holes 128 and 129 are formed.

  Mounting holes 124A and 125A are formed in the seat portions 124 and 125, respectively. The seat portion 124 is attached to the side wall 93 </ b> A of the box body 72 by inserting the screw N <b> 2 into the attachment hole 124 </ b> A and fastening it together with the grounding region of the light source driving substrate 110. Further, the seat portion 125 is attached to the frame 25 via the attachment hole 125A with a screw N4 (see FIG. 5). Here, since the shield box 120 and the frame 25 are made of metal, they are electrically connected by being screwed.

  As shown in FIG. 5, each semiconductor laser 74 is held by each holder 105 by being press-fitted into a through hole 105 </ b> A formed in the holder 105. The side wall 93A of the box body 72 is formed with a boss 106 that protrudes toward the light source drive board 110 (outside), and the boss 106 is formed with a female screw 106A to which the screw N3 is fastened. . Here, by supplying an electric current to the semiconductor laser 74 using a jig (not shown) and adjusting the optical path in a state in which the laser beam is emitted, the holder 105 is fastened to the boss 106 with a screw N3. The semiconductor laser 74 is fixed to the side wall 93A.

  Further, the side wall 93A is provided with four bosses 108 formed with female screws 108A for attaching the light source driving board 110. Of the four bosses 108, the lower two bosses 108 have the grounding region of the light source driving substrate 110 and the seat portion 124 fastened together by screws N 2, and the upper two bosses 108 (not shown) have The grounding area of the light source driving substrate 110 is fastened by a screw N2 (see FIG. 4). In FIG. 5, the boss 106 and the boss 108 are illustrated in the same cross section in order to make the arrangement of the holder 105 and the light source driving substrate 110 easier to understand.

  Next, the light source driving substrate 110 will be described.

  As shown in FIG. 4, the light source driving substrate 110 is a multi-layer circuit board in which a circuit is formed with a conductive pattern (copper foil) made of a conductive material such as copper on an insulating base material such as an epoxy resin, A driver IC (Integrated Circuit) 112 (see FIG. 7) as an example of an electronic component that drives the semiconductor lasers 74C, 74Y, 74K, and 74M (drives the light source) is mounted. The driver IC 112 is controlled to be turned on and off by the control unit 12 (see FIG. 1), and drives the semiconductor laser 74 by outputting a high speed signal (high frequency signal) during driving.

  The light source driving board 110 is provided with the above-described connectors 127A, 127B, and 127C. The four mounting holes 110A, 110B, 110C, and 110D and the lead wires 74A of the semiconductor lasers 74C, 74Y, 74K, and 74M are provided. A through hole 110E to be inserted is formed. After the lead wire 74A is inserted into the through hole 110E, the lead wire 74A is connected by soldering to the conductive pattern 113 that electrically connects the semiconductor laser 74 and the driver IC 112 in the first layer L1 (see FIG. 6) of the light source driving substrate 110. The periphery of the mounting holes 110A, 110B, 110C, and 110D is a grounding area.

  As illustrated in FIG. 6, the light source driving substrate 110 includes, as an example, a first layer L1, an insulating layer J1, a second layer L2, an adhesive layer J2, a third layer L3, an insulating layer J3, and a fourth layer in the thickness direction. It has the layer L4, and has a configuration in which the second layer L2 and the third layer L3 are bonded together by the adhesive layer J2. The first layer L1 is formed with the conductive pattern 113 described above, and has a mounting surface S1 on which the driver IC 112 and a plurality of electronic components 116 including resistors, capacitors, and transistors are mounted. The second layer L2 is an example of a second radio wave blocking unit, and forms an intermediate layer of the light source driving substrate 110. In addition, the second layer L2 is substantially entirely made of copper foil except for the portions where the mounting holes 110A, 110B, 110C, and 110D are formed, and wiring (not shown) connected to the light source driving substrate 110 is provided. Is grounded.

  In the third layer L3, a power supply circuit pattern (not shown) mainly for the driver IC 112 is formed. The fourth layer L4 is formed with a conductive pattern (not shown) that transmits a signal having a lower driving frequency than the driver IC 112, and has a mounting surface S2 on which a plurality of electronic components 116 are mounted. Here, in the light source driving substrate 110, the mounting surface S2 of the fourth layer L4 is disposed to face the side wall 93A (see FIG. 5) of the box body 72, and the mounting surface S1 of the first layer L1 is the farthest from the side wall 93A. It is arranged to become. That is, the mounting surface S <b> 1 is disposed at least on the side opposite to the box body 72 (see FIG. 5) side and provided outside the box body 72. On the other hand, the insulating layers J1 and J3 are, for example, glass epoxy substrates formed of glass fiber and epoxy resin, and the adhesive layer J2 is after the adhesive that has bonded the second layer L2 and the third layer L3 is cured. Layer. In FIG. 6, the thickness of the adhesive layer J2 is shown to be approximately the same as that of the insulating layers J1 and J2, but in actuality it is a layer thinner than the insulating layers J1 and J2.

  Next, the arrangement of the semiconductor laser 74 and the driver IC 112 will be described.

  FIG. 7 shows the entire second layer L2 of the light source driving substrate 110 when the side wall 93A (see FIG. 5) of the box body 72 is viewed from the shield box 120 side. The arrow Y direction indicates the upward direction, the arrow X direction indicates the horizontal direction, and the hatched portion is made of copper foil. In FIG. 7, in order to explain the arrangement relationship of each member, the semiconductor lasers 74C, 74Y, 74K attached to the driver IC 112 and the conductive pattern 113 in the first layer L1, and the holder 105 (see FIG. 5), 74M is projected onto the second layer L2.

  As shown in FIG. 7, the driver IC 112 is disposed close to the semiconductor laser 74, and the interval between the driver IC 112 and the semiconductor laser 74 is set to be shorter than the interval between the semiconductor lasers 74. Specifically, in FIG. 7, the interval between the semiconductor laser 74C and the semiconductor laser 74Y in the arrow X direction is Δd1, the interval between the semiconductor laser 74Y and the semiconductor laser 74K in the arrow X direction is Δd2, and the semiconductor laser 74K in the arrow X direction is The distance from the semiconductor laser 74M is assumed to be Δd3. In addition, the distance between the semiconductor laser 74 and the driver IC 112 is set so that the other end of the conductive pattern 113 is connected to the lead wire 74A of the semiconductor laser 74 to which one end of the conductive pattern 113 is connected. Expressed as the shortest distance in the arrow Y direction or the arrow X direction to the position of the pin (not shown), the distance between the semiconductor laser 74C and the driver IC 112C is d1, the distance between the semiconductor laser 74Y and the driver IC 112Y is d2, and the semiconductor laser 74K An interval between the driver IC 112K and the semiconductor laser 74M and the driver IC 112M is d4.

  Here, in the present embodiment, all of the intervals d1, d2, d3, d4 are shorter than the intervals Δd1, Δd2, Δd3. The second layer L2 covers the conductive patterns 113C, 113Y, 113K, and 113M. That is, the second layer L2 that is the second radio wave blocking means covers between the semiconductor laser 74 and the driver IC 112.

  Next, the operation of the first embodiment will be described.

  As shown in FIG. 8, in the optical scanning device 20, laser light LY, LM, LC, and LK (see FIG. 1) are emitted from the semiconductor laser 74 when the light source driving substrate 110 drives the semiconductor laser 74. The emitted laser light is reflected by the reflecting surface of the rotating polygon mirror 75 (see FIG. 1) and scanned in one direction (axial direction) of the photosensitive member 14 (see FIG. 1). In FIG. 8, the third layer L3 and the fourth layer L4 of the light source driving substrate 110 are not shown.

  Here, since the driver IC 112 is sandwiched between the shield box 120 and the second layer L2 of the light source driving board 110, the radio wave W generated in the circuit of the driver IC 112 or the first layer L1 of the light source driving board 110 is the first. It is blocked by the second layer L2 and does not leak into the box body 72, and is blocked by the shield box 120 and does not leak from the shield box 120 to the outside. In addition, since the driver IC 112 is sandwiched between the shield box 120 and the second layer L2 of the light source drive substrate 110, radio waves (not shown) traveling from the outside to the inside of the shield box 120 are also blocked by the shield box 120. .

  Further, as shown in FIG. 7, in the light source driving substrate 110, the distances d1, d2, d3, d4 between the semiconductor laser 74 and the driver IC 112 are shorter than the distances Δd1, Δd2, Δd3 between the semiconductor lasers 74. Therefore, the radio wave generated in each conductive pattern 113 is suppressed, and the conductive pattern 113 itself is difficult to receive the radio wave as an antenna and the radio wave is hardly generated, so that the radio wave generated in one conductive pattern 113 is transmitted to the other conductive pattern 113. It becomes difficult to affect. Further, in the light source driving substrate 110, as shown in FIG. 6, since the second layer L2 as an example of the second radio wave blocking means is provided in a plurality of intermediate layers, what is the mounting surface S1 of the first layer L1? An electronic component 116 different from the semiconductor laser 74 is mounted on the opposite mounting surface S2.

  Next, an example of an optical scanning device and an image forming apparatus according to the second embodiment of the present invention will be described.

  The image forming apparatus of the second embodiment is mechanically the same as the image forming apparatus 10 of the first embodiment described above. However, as a different structure, a light source driving board 132 is used instead of the light source driving board 110. Is provided. For this reason, the second embodiment is also described as the image forming apparatus 10, and basically the same members as those in the first embodiment described above are given the same reference numerals as those in the first embodiment. The description is omitted.

  FIG. 9 shows an optical scanning device 130 of the second embodiment. The optical scanning device 130 is provided with a light source driving substrate 132 instead of the light source driving substrate 110 of the first embodiment. The light source driving substrate 132 includes a first layer L5 on which the driver ICs 112 (112Y, 112M, 112C, and 112K) are mounted, an insulating layer J4 that holds the first layer L5, and a second layer on which the insulating layer J4 is attached. L6. On the first layer L5, the conductive pattern 113 (not shown in FIG. 9) is formed, and a plurality of electronic components (not shown) are mounted. The second layer L6 is made of an iron substrate, and is grounded via a wiring (not shown) connected to the light source driving substrate 132. Since the second layer L6 is an iron substrate, it is not necessary to provide radio wave blocking means on the light source driving substrate 132 in addition to the second layer L6. Also in the light source drive substrate 132, the distance between the driver IC 112 and the semiconductor laser 74 is shorter than the distance between the semiconductor lasers 74. The insulating layer J4 is formed of the same material as the above-described insulating layers J1 and J3.

  Next, the operation of the second embodiment will be described.

  In the optical scanning device 130, the light source driving substrate 132 drives the semiconductor laser 74 to emit laser beams LY, LM, LC, and LK (see FIG. 1) from the semiconductor laser 74. The emitted laser light is reflected by the reflecting surface of the rotating polygon mirror 75 (see FIG. 1) and scanned in one direction (axial direction) of the photosensitive member 14 (see FIG. 1).

  Here, since the driver IC 112 is sandwiched between the shield box 120 and the second layer L6 (iron substrate) of the light source driving board 132, the radio wave generated in the circuit of the driver IC 112 or the first layer L5 of the light source driving board 132. W is blocked by the second layer L6 and does not leak into the box body 72, and W is blocked by the shield box 120 and does not leak to the outside from the shield box 120. In addition, since the driver IC 112 is sandwiched between the shield box 120 and the second layer L6 of the light source drive substrate 132, radio waves traveling from the outside to the inside of the shield box 120 are also blocked by the shield box 120.

  In addition, this invention is not limited to said embodiment.

  The number of semiconductor lasers 74 may be one in the case of a single-color image forming apparatus, and five or more semiconductor lasers 74 may be provided in accordance with the number of toner colors when using five or more colors including special colors. Further, not only the second layer L2, but also the third layer L3, or the third layer L3 and the fourth layer L4 may be made of copper foil to block radio waves. Further, the surface of the side wall 93A of the box body 72 may be covered with metal (for example, gold plating) to block radio waves. Further, the number of layers of the light source driving substrates 110 and 132 may be three or more than five. In addition, the light source driving substrate 132 may be a plurality of layers of three or more layers, and a radio wave blocking layer formed of copper foil may be provided in addition to the iron substrate.

10 Image forming apparatus 14 Photosensitive member (irradiated body, charged member)
18 Development unit (developer image forming means)
20 Optical scanning device 30 Primary transfer unit (transfer means)
44 Secondary transfer roll (transfer means)
60 Fixing device (fixing means)
72 Box body (optical box)
74 Semiconductor laser (light source)
75 Polygon mirror (scanning means)
110 Light source drive board (drive board)
112 Driver IC (electronic component that drives the light source)
120 Shield box (first radio wave blocking means)
130 Optical Scanning Device 132 Light Source Drive Board (Drive Board)
L2 second layer (second radio wave blocking means)
L6 second layer (second radio wave blocking means, iron substrate)

Claims (5)

A light source that is mounted outside the optical box and emits light;
Provided inside the optical box, a scanning means for scanning the light incident from the light source in one direction on the irradiated object,
With mounting surface on which an electronic component for driving at least said light source is mounted is disposed opposite at least the optical box side is attached to a different site from the outside of the light source of the optical box, driving the light source A plurality of layers of driving substrates for emitting light,
A first radio wave cutoff means for cutting off radio waves vignetting mounted on the outside of the optical box so as to cover the mounting surface of the driving substrate,
A second radio wave blocking means for blocking radio waves formed so as to cover at least a mounting range of an electronic component that drives the light source in at least one layer of the drive board;
An optical scanning device.   The light source and a plurality of electronic components for driving the light source are provided, and the interval between the light source and the electronic component for driving the light source is shorter than the interval between the plurality of light sources, and the second radio wave blocking means The optical scanning device according to claim 1, which covers a space between the light source and an electronic component that drives the light source.   The optical scanning device according to claim 1, wherein the driving substrate has a plurality of layers of three or more layers, and the second radio wave blocking means is formed in an intermediate layer.   4. The optical scanning device according to claim 1, wherein the drive substrate includes an iron substrate as the second radio wave blocking means. 5. A member to be rotated and a charged member whose outer periphery is charged;
The optical scanning device according to any one of claims 1 to 4, wherein a latent image is formed by irradiating light on an outer periphery of the charged member to be charged;
Developer image forming means for developing a latent image on the periphery of the member to be charged with a developer to form a developer image;
Transfer means for transferring the developer image formed by the developer image forming means to a recording medium;
Fixing means for fixing the developer image transferred by the transfer means on a recording medium;
An image forming apparatus.

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