JP6702261B2 - Optical scanning device, image forming device, and cleaning control method - Google Patents

Description

  The present invention relates to an electrophotographic image forming apparatus, an optical scanning device mounted on the image forming apparatus, and a cleaning control method executed by the optical scanning device.

  An electrophotographic image forming apparatus is provided with an optical scanning device that forms an electrostatic latent image corresponding to image data on an image bearing member such as a photosensitive drum. In the optical scanning device, light based on image data emitted from a light source and scanned by an optical scanning unit such as a polygon mirror is directed from the light transmitting unit provided in the housing of the optical scanning device toward the image carrier. Is ejected.

  Here, when foreign matter such as scattered toner adheres to the light transmitting portion, the amount of light emitted from the light transmitting portion decreases. On the other hand, an image forming apparatus including a cleaning unit that cleans the light transmitting unit is known as a related art (see Patent Document 1). Specifically, in the related art, the cleaning unit is capable of reciprocating between both ends of the light transmitting unit.

JP, 2011-158566, A

  However, in the related art, in order to control the movement of the cleaning unit, it is necessary to provide a sensor capable of detecting the presence or absence of the cleaning unit at each end of the light transmitting unit.

  An object of the present invention is to provide an optical scanning device, an image forming apparatus, and a cleaning control method capable of simplifying the configuration used for controlling the movement of the cleaning unit.

  An optical scanning device according to one aspect of the present invention includes an optical scanning unit, a housing, a cleaning unit, a light detection unit, a first drive control unit, a drive processing unit, and a second drive control unit. Prepare The optical scanning unit scans the light emitted from the light source. The housing has a light transmitting portion through which the light scanned by the light scanning portion is transmitted. The cleaning unit is provided on the outside of the housing so as to be movable along the scanning direction of the light by the light scanning unit while being in contact with the light transmitting unit. Are reciprocated in a driving range including each non-transmissive region outside the scanning range sandwiching the transmissive region within the scanning range. The light detection unit is provided in the cleaning unit and detects the light scanned by the light scanning unit. The first drive control unit starts the movement of the cleaning unit in each of the forward path and the return path. The drive processing unit drives the light source and the optical scanning unit while the cleaning unit is moving. The second drive control unit is a reference in which a non-detection state in which the light detection unit does not detect the light is preset after the first drive control unit starts the movement of the cleaning unit in each of the forward path and the return path. The movement of the cleaning unit is stopped when the cleaning is continued for a time.

  An image forming apparatus according to another aspect of the present invention includes the optical scanning device.

  A cleaning control method according to another aspect of the present invention includes an optical scanning unit that scans light emitted from a light source, a housing that includes a light transmitting unit that transmits the light scanned by the optical scanning unit, and the housing. Is provided movably along the scanning direction of the light by the optical scanning unit in a state of being in contact with the light transmissive unit on the outer side of the transmissive region within the scanning range of the light by the optical scanning unit in the translucent unit. A cleaning unit that is reciprocally moved in a drive range that includes each non-transmissive region outside the scanning range that sandwiches, and a light detection unit that is provided in the cleaning unit and that detects the light scanned by the optical scanning unit. An optical scanning device provided to start the movement of the cleaning unit in each of the forward path and the return path; drive the light source and the optical scanning unit during movement of the cleaning unit; and the first drive control unit. After the movement of the cleaning unit in each of the forward path and the return path is started by the movement of the cleaning unit when the non-detection state in which the light is not detected by the light detection unit continues beyond a preset reference time. Including stopping.

  According to the present invention, an optical scanning device, an image forming apparatus, and a cleaning control method capable of simplifying the configuration used for movement control of a cleaning unit are realized.

FIG. 1 is a diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram showing the system configuration of the image forming apparatus according to the embodiment of the present invention. FIG. 3 is a view showing the arrangement of the optical scanning device of the image forming apparatus according to the embodiment of the present invention. FIG. 4 is a diagram showing the configuration of the cleaning mechanism of the image forming apparatus according to the embodiment of the present invention. FIG. 5 is a diagram showing the configuration of the cleaning unit of the image forming apparatus according to the embodiment of the present invention. FIG. 6 is a diagram showing the configuration of the cleaning unit of the image forming apparatus according to the embodiment of the present invention. FIG. 7 is a flowchart showing an example of threshold setting processing executed by the image forming apparatus according to the embodiment of the present invention. FIG. 8 is a flowchart showing an example of the cleaning process executed by the image forming apparatus according to the embodiment of the present invention. FIG. 9 is a flowchart showing an example of cleaning control processing executed by the image forming apparatus according to the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. The following embodiments are examples of embodying the present invention, and do not limit the technical scope of the present invention.

[Schematic Configuration of Image Forming Apparatus 10]
First, a schematic configuration of an image forming apparatus 10 according to an exemplary embodiment of the present invention will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a schematic cross-sectional view showing the configuration of the image forming apparatus 10.

  For convenience of description, the vertical direction is defined as the vertical direction D1 when the image forming apparatus 10 can be used (the state shown in FIG. 1). Further, the front-rear direction D2 is defined with the surface on the left side of the paper of the image forming apparatus 10 shown in FIG. 1 as the front surface. Further, the left-right direction D3 is defined with reference to the front of the image forming apparatus 10 in the installed state.

  The image forming apparatus 10 is a multi-function peripheral having a print function for forming an image based on image data and a plurality of functions such as a scan function, a facsimile function, and a copy function. Further, the present invention can be applied to an image forming apparatus such as a printer device, a facsimile device, and a copying machine.

  As shown in FIG. 1, the image forming apparatus 10 includes an ADF 1, an image reading unit 2, an image forming unit 3, a paper feeding unit 4, a control unit 5, an operation display unit 6, and a storage unit 7.

  The ADF 1 is an automatic document feeder that includes a document setting unit (not shown), a plurality of transport rollers, a document retainer, and a paper discharge unit, and transports a document read by the image reading unit 2.

  The image reading unit 2 includes a document table (not shown), a light source, a plurality of mirrors, an optical lens, and a CCD, and can read image data from a document.

  The control unit 5 includes control devices such as a CPU, a ROM, a RAM, and an EEPROM (registered trademark), which are not shown. The CPU is a processor that executes various arithmetic processes. The ROM is a non-volatile storage device in which information such as a control program for causing the CPU to execute various processes is stored in advance. The RAM is a volatile storage device used as a temporary storage memory (working area) for various processes executed by the CPU. The EEPROM is a non-volatile storage device. In the control unit 5, the CPU executes various control programs stored in advance in the ROM. As a result, the image forming apparatus 10 is comprehensively controlled by the control unit 5. The control unit 5 may be configured by an electronic circuit such as an integrated circuit (ASIC), and is a control unit provided separately from the main control unit that totally controls the image forming apparatus 10. You may.

  The operation display unit 6 is a display unit such as a liquid crystal display that displays various kinds of information according to a control instruction from the control unit 5, and an operation key or a touch panel that inputs various kinds of information to the control unit 5 according to a user operation. Has an operation unit such as.

  The storage unit 7 is a non-volatile storage device. For example, the storage unit 7 is a storage device such as a flash memory, an SSD (solid state drive), or an HDD (hard disk drive). The storage unit 7 stores the image data and the like read by the image reading unit 2. The storage unit 7 may be the RAM or the EEPROM of the control unit 5.

  The image forming unit 3 can form a color or monochrome image by an electrophotographic method based on the image data read by the image reading unit 2. Further, the image forming unit 3 can also form an image based on image data input from an information processing device such as an external personal computer.

  As shown in FIG. 1, the image forming unit 3 includes a plurality of image forming units 31 to 34, optical scanning devices 35 to 36, an intermediate transfer belt 37, a secondary transfer roller 38, a fixing device 39, and a paper discharge tray 40. Equipped with.

  The image forming unit 31 is an electrophotographic image forming unit corresponding to Y (yellow), the image forming unit 32 is C (cyan), the image forming unit 33 is M (magenta), and the image forming unit 34 is K (black). is there. Each of the image forming units 31 to 34 includes a photoconductor drum, a charging roller, a developing unit, a primary transfer roller, and a drum cleaning unit.

  The optical scanning device 35 forms an electrostatic latent image on the surface of the photoconductor drum provided in each of the image forming units 31 to 32. The optical scanning device 36 forms an electrostatic latent image on the surface of the photoconductor drum provided in each of the image forming units 33 to 34. As shown in FIG. 1, the optical scanning devices 35 to 36 are provided below the image forming units 31 to 34.

  The intermediate transfer belt 37 is an endless belt member to which the toner image formed on the surface of the photosensitive drum provided in each of the image forming units 31 to 34 is transferred. The secondary transfer roller 38 transfers the toner image transferred on the surface of the intermediate transfer belt 37 to the sheet supplied from the paper feeding unit 4. The fixing device 39 melts and fixes the toner image transferred onto the sheet by the secondary transfer roller 38 onto the sheet. The sheet on which the toner image is fixed by the fixing device 39 is discharged to the discharge tray 40.

  The paper feed unit 4 includes a paper feed cassette and a plurality of transport rollers, and supplies the sheets stored in the paper feed cassette to the image forming unit 3. For example, the sheets accommodated in the paper feed cassette are sheet materials such as paper, coated paper, postcards, envelopes, and OHP sheets.

  In the image forming section 3, a color image is formed on the sheet supplied from the sheet feeding section 4 by the following procedure, and the sheet after the image formation is discharged to the sheet discharge tray 40.

  First, in the image forming unit 31, the surface of the photosensitive drum is uniformly charged by the charging roller to a predetermined potential. Next, the optical scanning device 35 irradiates the surface of the photosensitive drum with light based on image data. As a result, an electrostatic latent image corresponding to image data is formed on the surface of the photosensitive drum. Then, the electrostatic latent image on the photosensitive drum is developed (visualized) as a yellow toner image by the developing unit.

  Subsequently, the yellow toner image formed on the photosensitive drum is transferred to the intermediate transfer belt 37 by the primary transfer roller. On the other hand, the toner remaining on the surface of the photosensitive drum is removed by the drum cleaning unit.

  In each of the image forming units 32 to 34, a toner image is formed on the photoconductor drum by the same processing procedure as that of the image forming unit 31. Then, the toner images of the respective colors formed on the photosensitive drums of the image forming units 32 to 34 are sequentially transferred onto the yellow toner images transferred to the intermediate transfer belt 37. As a result, the yellow, cyan, magenta, and black toner images are transferred onto the surface of the intermediate transfer belt 37 in an overlapping manner. Then, the color toner image transferred to the intermediate transfer belt 37 is transferred to the sheet supplied from the paper feeding unit 4 by the secondary transfer roller 38. Then, on the sheet onto which the toner image has been transferred, the toner image is fused and fixed by the fixing device 39 to form an image, and the sheet is discharged to the paper discharge tray 40.

[Configuration of Optical Scanning Device 35]
Next, the configuration of the optical scanning device 35 will be described with reference to FIGS. 3 and 4. Here, FIG. 3 is a schematic sectional view showing the configuration of the optical scanning device 35. Further, FIG. 4 is a plan view showing the configuration of the upper part of the housing 350. The two-dot chain lines in FIGS. 3 and 4 show the optical paths of the lights L1 and L2 emitted from the light sources 351A to 351B (see FIG. 4).

  As shown in FIGS. 3 and 4, the optical scanning device 35 includes light sources 351A to 351B, a polygon mirror 352, a polygon motor 353, fθ lenses 354A to 354B, fθ lenses 355A to 355B, folding mirrors 356A to 356B, and folding mirrors. 357A-357B, folding mirrors 358A-358B, and a housing 350 that houses these components. The housing 350 has translucent parts 359A-359B, as shown in FIGS. The optical scanning device 36 includes the same components as the optical scanning device 35.

  The light sources 351A to 351B emit light corresponding to image data. For example, the light sources 351A-351B are laser diodes. The light source 351A emits light L1 (see FIG. 4) with which the photosensitive drum of the image forming unit 31 is irradiated. Further, the light source 351B emits light L2 (see FIG. 4) with which the photosensitive drum of the image forming unit 32 is irradiated.

  The polygon mirror 352 scans the light emitted from the light sources 351A to 351B. For example, as shown in FIG. 4, the polygon mirror 352 is formed in a regular hexagonal shape in plan view, and has a plurality of reflecting surfaces that reflect the light emitted from each of the light sources 351A to 351B.

  The polygon motor 353 supplies a rotational driving force to the polygon mirror 352 to rotate the polygon mirror 352. As shown in FIG. 3, the polygon mirror 352 is fixedly provided on the rotating shaft 353A of the polygon motor 353.

  The polygon mirror 352 rotates in the rotation direction D4 shown in FIG. 4 about the rotation shaft 353A by the rotation driving force supplied from the polygon motor 353. As a result, the polygon mirror 352 sequentially scans the light on each of the reflecting surfaces as the polygon mirror 352 rotates. Specifically, the polygon mirror 352 scans the light L1 emitted from the light source 351A in the scanning direction D31 (right direction in the left-right direction D3) shown in FIG. Further, the polygon mirror 352 scans the light L2 emitted from the light source 351B in the scanning direction D32 (left direction in the left-right direction D3) shown in FIG. Here, the polygon mirror 352 is an example of the optical scanning unit in the present invention.

  The fθ lens 354A, the fθ lens 355A, the folding mirror 356A, the folding mirror 357A, the folding mirror 358A, and the light transmitting portion 359A are provided corresponding to the light source 351A. The fθ lens 354A and the fθ lens 355A convert the light L1 scanned by the polygon mirror 352 at a constant angular velocity into light scanned at a constant velocity along the scanning direction D31. The folding mirror 356A, the folding mirror 357A, and the folding mirror 358A guide the light L1 that has passed through the fθ lens 354A and the fθ lens 355A to the light transmitting unit 359A.

  On the other hand, the fθ lens 354B, the fθ lens 355B, the folding mirror 356B, the folding mirror 357B, the folding mirror 358B, and the light transmitting portion 359B are provided corresponding to the light source 351B. The fθ lens 354B and the fθ lens 355B convert the light L2 scanned by the polygon mirror 352 at a constant angular velocity into light scanned at a constant velocity along the scanning direction D32. The folding mirror 356B, the folding mirror 357B, and the folding mirror 358B guide the light L2 that has passed through the fθ lens 354B and the fθ lens 355B to the light transmitting unit 359B.

  Lights scanned by the polygon mirror 352 are transmitted through the light transmitting portions 359A to 359B. For example, the translucent portions 359A to 359B are transparent glass plates or acrylic plates that are formed in the upper portion of the housing 350 and close the long openings in the scanning direction D31. The light L1 transmitted through the light transmitting portion 359A is emitted to the photosensitive drum of the image forming unit 31. Further, the light L2 transmitted through the light transmitting portion 359B is emitted to the photosensitive drum of the image forming unit 32.

  Here, in the optical scanning device 35, foreign matter such as scattered toner may adhere to the light transmitting portions 359A to 359B, and the light amount of the light L1 to L2 emitted from the light transmitting portions 359A to 359B may decrease. On the other hand, the optical scanning device 35 is provided with two cleaning mechanisms 8 corresponding to the light transmitting parts 359A to 359B.

[Configuration of cleaning mechanism 8]
Next, the configuration of the cleaning mechanism 8 will be described with reference to FIGS. 2 and 4 to 6. Here, FIG. 5 is a perspective view showing a configuration of the cleaning unit 82 in a state of being supported by the screw shaft 811. Further, FIG. 6 is a perspective view showing the configuration of the cleaning unit 82 in a state of being removed from the screw shaft 811. Note that FIG. 6 shows the cleaning unit 82 with the contact portion 824 removed.

  Here, each of the two cleaning mechanisms 8 has the same constituent element. Therefore, in the following, only the cleaning mechanism 8 corresponding to the light transmitting portion 359A will be described, and description of the cleaning mechanism 8 corresponding to the light transmitting portion 359B will be omitted. The description given below is similarly applied to the cleaning mechanism 8 corresponding to the light transmitting portion 359B.

  The cleaning mechanism 8 cleans the surface of the light transmitting portion 359A. As shown in FIGS. 2 and 4, the cleaning mechanism 8 includes a support portion 81, a cleaning portion 82, and a motor 83.

  The support part 81 supports the cleaning part 82 so as to be movable along the scanning direction D31. As shown in FIG. 4, the support portion 81 has a screw shaft 811, and guide portions 812 to 813.

  The screw shaft 811 supports the cleaning unit 82 and supplies a driving force for moving the cleaning unit 82 in the scanning direction D31. As shown in FIG. 5, the screw shaft 811 is a shaft member having a spiral groove portion 811A formed on the outer surface thereof. As shown in FIG. 4, the screw shaft 811 is arranged along the longitudinal direction of the light transmitting portion 359A on the rear side of the light transmitting portion 359A. The screw shaft 811 is rotatably supported by a bearing portion 811B (see FIG. 4) provided on the upper portion of the housing 350. Further, the screw shaft 811 is transmitted with a rotational driving force from the motor 83 via a gear 811C (see FIG. 4) provided at one end in the longitudinal direction.

  The guide parts 812 to 813 support the cleaning part 82 and guide the cleaning part 82 along the scanning direction D31. For example, the guide portions 812 to 813 are columnar members. As shown in FIG. 4, the guide portion 812 is arranged along the longitudinal direction of the light transmitting portion 359A on the rear side portion of the screw shaft 811. Further, the guide portion 813 is arranged along the longitudinal direction of the light transmitting portion 359A on the front side portion of the light transmitting portion 359A. Both ends of the guide portions 812 to 813 are supported by the bearing portion 811B. The guide parts 812 to 813 may be integrally formed with the housing 350 at the upper part of the housing 350.

  The cleaning unit 82 is provided outside the housing 350 so as to be movable along the scanning direction D31 of the light L1 by the polygon mirror 352 while being in contact with the light transmitting unit 359A. As shown in FIGS. 5 and 6, the cleaning portion 82 includes a bearing portion 821, a first arm portion 822, a second arm portion 823, and a contact portion 824.

  The bearing portion 821 is formed in a tubular shape as shown in FIG. The bearing portion 821 is formed integrally with the first arm portion 822 and the second arm portion 823. As shown in FIG. 6, the bearing portion 821 has a shaft hole 821A into which the screw shaft 811 is inserted. Inside the shaft hole 821A, a protrusion 821B (see FIG. 6) capable of engaging with the groove 811A of the screw shaft 811 is provided. In addition, the bearing portion 821 has a protruding portion 821C that protrudes downward. The protrusion 821C is inserted into a groove (not shown) formed in the upper portion of the housing 350 along the scanning direction D31. As a result, the cleaning unit 82 is guided along the scanning direction D31.

  The first arm portion 822 is provided so as to project rearward from the outer peripheral surface of the bearing portion 821. As shown in FIG. 6, a grip portion 822A capable of gripping the guide portion 812 is formed at the tip end portion of the first arm portion 822 in the projecting direction. The cleaning unit 82 is guided along the scanning direction D31 by the guide unit 812 being held by the holding unit 822A.

  The second arm portion 823 is provided so as to project from the outer peripheral surface of the bearing portion 821 in a direction opposite to the projecting direction of the first arm portion 822. As shown in FIG. 6, a grip portion 823A capable of gripping the guide portion 813 is formed at the tip end portion of the second arm portion 823 in the projecting direction. The cleaning unit 82 is guided along the scanning direction D31 by the gripping unit 823A gripping the guide unit 813. Further, the second arm portion 823 has a mounting portion 823B (see FIG. 6) to which the contact portion 824 can be attached/detached. The mounting portion 823B is provided on the lower surface of the second arm portion 823 at a position facing the translucent portion 359A.

  The contact portion 824 is provided in contact with the surface of the light transmitting portion 359A. For example, the contact portion 824 is a plate-shaped elastic member. The contact portion 824 is attached to the cleaning portion 82 by being attached to the attachment portion 823B of the second arm portion 823. The contact portion 824 may be a brush-shaped member.

  The motor 83 rotates the screw shaft 811. When the screw shaft 811 is rotated by the motor 83, the protrusion 821B of the bearing portion 821 inserted into the screw shaft 811 is guided to the groove portion 811A of the screw shaft 811 so that the cleaning unit 82 can rotate the shaft of the screw shaft 811. Moved along the direction. For example, in the cleaning mechanism 8, the cleaning unit 82 is moved in the scanning direction D31 when the motor 83 is rotated in the predetermined first direction. Further, in the cleaning mechanism 8, when the motor 83 is rotated in the second direction opposite to the first direction, the cleaning unit 82 is moved in the direction opposite to the scanning direction D31.

  In the cleaning mechanism 8, the cleaning unit 82 is reciprocally moved within a predetermined drive range R1 (see FIG. 4). Specifically, the drive range R1 includes a transmissive region R11 (see FIG. 4) within the scanning range of the light L1 by the polygon mirror 352 in the translucent portion 359A, and a non-transmissive region R12 (which is outside the scanning range and sandwiches the transmissive region R11). (See FIG. 4) This is the range including each. The drive range R1 is set so that the cleaning unit 82 can be retracted from the scanning range at both ends in the longitudinal direction.

  For example, the cleaning unit 82 is moved back and forth in the drive range R1 from the home position P1 (see FIG. 4), which is one end of the drive range R1. Hereinafter, the movement path when the cleaning unit 82 moves from the home position P1 to the folding position P2 (see FIG. 4) which is the other end in the drive range R1 is referred to as a forward path. Further, the movement path when the cleaning unit 82 moves from the folding position P2 to the home position P1 is referred to as a return path.

  By the way, a configuration is provided in which a sensor capable of detecting the presence or absence of the cleaning unit 82 is provided at each of the upstream end and the downstream end of the light transmitting unit 359A in the scanning direction D31 and the control of the reciprocating movement of the cleaning unit 82 is performed using the sensor. Are known.

  On the other hand, in the image forming apparatus 10, as described below, the configuration used for controlling the movement of the cleaning unit 82 can be simplified.

  Specifically, the cleaning unit 82 includes a light detection unit 825, as shown in FIGS. 5 and 6.

  The light detection unit 825 detects the light amount of the light L1 scanned by the polygon mirror 352. Specifically, the light detection unit 825 is an electronic circuit including a light receiving element such as a photodiode, and outputs an electric signal according to the amount of light received by the light receiving element.

  For example, as shown in FIG. 5, the light detection unit 825 is provided downstream of the contact unit 824 of the cleaning unit 82 in the moving direction (scanning direction D31) of the cleaning unit 82 in the forward path. Specifically, as shown in FIGS. 5 and 6, the photodetector 825 is provided on the right side of the second arm 823 so as to face the translucent portion 359A.

  The light detection unit 825 may be able to detect only the presence or absence of the light L1 scanned by the polygon mirror 352. The light detection unit 825 may be provided on the upstream side of the contact portion 824 of the cleaning unit 82 in the moving direction of the cleaning unit 82 in the forward path (scanning direction D31).

  In addition, a cleaning control program for causing the CPU to execute a threshold value setting process (see the flowchart of FIG. 7) and a cleaning control process (see the flowchart of FIG. 9) described below is stored in the ROM of the control unit 5 in advance. ing. The cleaning control program may be recorded in a computer-readable recording medium such as a CD, a DVD, or a flash memory, and may be read from the recording medium and installed in the storage unit 7.

  Then, as shown in FIG. 2, the control unit 5 includes a first drive control unit 51, a drive processing unit 52, and a second drive control unit 53. Specifically, the control unit 5 uses the CPU to execute the cleaning control program stored in the ROM. Thereby, the control unit 5 functions as the first drive control unit 51, the drive processing unit 52, and the second drive control unit 53. The device including the optical scanning device 35 and the control unit 5 is an example of the optical scanning device in the present invention.

  The first drive control unit 51 starts the movement of the cleaning unit 82 in each of the forward path and the return path.

  For example, the first drive control unit 51 starts the movement of the cleaning unit 82 in the forward path when the predetermined first condition is satisfied. Specifically, the first drive control unit 51 rotates the motor 83 in the first direction to move the cleaning unit 82 from the home position P1 toward the folding position P2.

  For example, the first condition is that the image forming apparatus 10 is turned on, the sleep state in which some functions of the image forming apparatus 10 are stopped is returned to the normal state, and the immediately preceding first condition is satisfied. For example, the cumulative number of printed sheets from the time exceeds a predetermined number, and a predetermined first operation is performed on the operation display unit 6.

  In addition, the first drive control unit 51 starts the movement of the cleaning unit 82 in the return path after the movement of the cleaning unit 82 in the outward path is stopped by the second drive control unit 53 described later. Specifically, the first drive control unit 51 rotates the motor 83 in the second direction to move the cleaning unit 82 from the folding position P2 to the home position P1.

  The drive processing unit 52 drives the light source 351A and the polygon mirror 352 while the cleaning unit 82 is moving.

  For example, when the first drive control unit 51 starts moving the cleaning unit 82 in the forward path, the drive processing unit 52 causes the light source 351A to move in advance before the first drive control unit 51 starts moving the cleaning unit 82. The polygon motor 353 is rotated while the light is emitted at a predetermined reference light amount.

  The drive processing unit 52 may rotate the polygon motor 353 while causing the light sources 351A and 351B to emit light after the first drive control unit 51 starts moving the cleaning unit 82.

  The second drive control unit 53 is preset with a non-detection state in which the light detection unit 825 does not detect the light L1 after the first drive control unit 51 starts moving the cleaning unit 82 in each of the forward path and the return path. When it continues for more than the reference time, the movement of the cleaning unit 82 is stopped.

  For example, the second drive control unit 53 causes the non-detection state to exceed the first reference time preset as the reference time after the first drive control unit 51 starts moving the cleaning unit 82 in the forward path. If the cleaning is continued, the movement of the cleaning unit 82 is stopped.

  Specifically, the first reference time is a time longer than the scanning period of the light L1 by the polygon mirror 352, and the light detection unit 825 in the cleaning unit 82 moved by the first drive control unit 51 in the forward path. The time is longer than the time from when the light receiving element is retracted from the transmissive region R11 to when the entire cleaning unit 82 is retracted from the transmissive region R11.

  In addition, the second drive control unit 53 causes the non-detection state to exceed a second reference time preset as the reference time after the first drive control unit 51 starts moving the cleaning unit 82 in the return path. If the cleaning is continued, the movement of the cleaning unit 82 is stopped.

  Specifically, the second reference time is longer than the scanning period of the light L1 by the polygon mirror 352, and the light detection unit 825 is included in the cleaning unit 82 that is moved in the backward path by the first drive control unit 51. The time is longer than the time from when the light receiving element is retracted from the transmissive region R11 to when the entire cleaning unit 82 is retracted from the transmissive region R11.

  Here, in the image forming apparatus 10, the light detection unit 825 is provided on the downstream side of the contact unit 824 in the cleaning unit 82 in the scanning direction D31. Therefore, the lower limit of the second reference time is shorter than the lower limit of the first reference time by the moving time of the second arm portion 823 provided with the contact portion 824. In view of this, in the image forming apparatus 10, the second reference time is set to be shorter than the first reference time. As a result, it is possible to shorten the drive range R1 as compared with the configuration in which the first reference time and the second reference time are set to the same length of time.

  In the image forming apparatus 10, when the light detection unit 825 is provided on the upstream side of the contact unit 824 in the cleaning unit 82 in the scanning direction D31, the second reference time is longer than the first reference time. It may be set. Also, the first reference time and the second reference time may be set to the same length of time. Further, the first reference time and the second reference time may be arbitrarily set so that the driving range R1 is a desired area in the light transmitting section 359A.

  In addition, a light-shielding seal member that covers each of the non-transmissive regions R12 may be provided on the outer or inner surface of the housing 350 in the light transmitting portion 359A.

  By the way, after the transparent portion 359A is cleaned by using the cleaning portion 82, stains may remain on the transparent portion 359A. In this case, the light amount of the light L1 emitted from the light transmitting unit 359A in the optical scanning device 35 decreases.

  On the other hand, in the image forming apparatus 10, as described below, it is possible to suppress a decrease in the light amount of the light L1 emitted from the light transmitting portion 359A due to contamination of the light transmitting portion 359A.

  Specifically, the control unit 5 controls the light emission of the light source 351A based on the image data when the light amount of the light L1 detected by the light detection unit 825 during the movement of the cleaning unit 82 is less than a predetermined threshold value. One of a light amount correction process of correcting the light amount and a cleaning process of reciprocating the cleaning unit 82 within the drive range R1 is executed.

  For example, the control unit 5 performs the cleaning process by functioning as the first drive control unit 51, the drive processing unit 52, and the second drive control unit 53 when the first condition is satisfied. The first condition is different from the condition that the light amount of the light L1 detected by the light detection unit 825 during the movement of the cleaning unit 82 is less than the threshold value.

  Then, the control unit 5 causes the light amount of the light L1 detected by the light detection unit 825 to be less than the threshold value while the cleaning unit 82 is moving on the return path while the cleaning process is performed according to the satisfaction of the first condition. If so, one of the light amount correction process and the cleaning process is executed.

  Further, the control unit 5 executes the cleaning process based on the determination that the light amount of the light L1 detected by the light detection unit 825 during the movement of the cleaning unit 82 is less than the threshold value. When the light amount of the light L1 detected by the light detection unit 825 during the movement on the return path is less than the threshold value, one of the light amount correction process and the cleaning process is executed.

  For example, when the cleaning unit 82 is moved in the transmission region R11 on the return path, the control unit 5 uses the light detection unit 825 to detect the light amount of the light L1 at predetermined time intervals. The control unit 5 then detects the amount of light L1 detected by the light detection unit 825 in one or more of the divided ranges corresponding to the time intervals included in the scanning range of the light L1 by the polygon mirror 352. Is less than the threshold value, one of the light amount correction process and the cleaning process is executed.

  For example, when the cleaning unit 82 is executing the cleaning process and the light amount of the light L1 detected by the light detection unit 825 during the movement of the cleaning unit 82 in the return path is less than the threshold value, the first condition is satisfied. Either the light amount correction process or the cleaning process is executed based on the number of times the cleaning process is executed after the above condition is satisfied. For example, the control unit 5 executes the cleaning process when the number of executions of the cleaning process after the satisfaction of the first condition is equal to or less than a predetermined upper limit number, and when the number of executions exceeds the upper limit number, the light amount correction is performed. Execute the process.

  For example, in the light amount correction process, the control unit 5 increases the light emission amount of the light source 351A during the period in which the light detection amount of the light detection unit 825 falls below the threshold value in the scanning period of the light L1 by the polygon mirror 352. Thus, the supply amount of the drive current by the light source drive unit (not shown) that supplies the drive current to the light source 351A is set.

  The control unit 5 performs one of the light amount correction process and the cleaning process based on the difference in the light amount of the light L1 detected by the light detection unit 825 during each movement of the forward path and the backward path of the cleaning unit 82. One may be executed. For example, the control unit 5 determines in advance a difference from the detected light amount of the light L1 by the light detection unit 825 on the outward path in the divided range in which the detected light amount of the light L1 by the light detection unit 825 on the return path is less than the threshold value. The light amount correction process may be executed when the specific light amount is equal to or less than the specified specific light amount, and the cleaning process may be executed when the specific light amount is exceeded. Thereby, it is possible to switch the light amount correction processing and the cleaning processing depending on the presence or absence or the degree of the cleaning effect of the cleaning processing.

  Further, the control unit 5 performs the light amount correction process when the light amount of the light L1 detected by the light detection unit 825 during the movement of the cleaning unit 82 in the outward path is less than the threshold value during the execution of the cleaning process. Also, either one of the cleaning processing may be executed. In addition, the control unit 5 determines whether the light amount of the light L1 detected by the light detection unit 825 during the movement of the cleaning unit 82 in the forward path or the return path is less than the threshold value during execution of the cleaning process. Both the light amount correction process and the cleaning process may be executed.

  Here, the control unit 5 executes the cleaning process even when a predetermined second condition different from the first condition is satisfied. The second condition is a condition different from that the light amount of the light L1 detected by the light detection unit 825 during the movement of the cleaning unit 82 is less than the threshold value. Here, the first condition and the second condition are examples of the cleaning condition in the present invention.

  For example, the second condition is that a predetermined second operation different from the first operation is performed on the operation display unit 6, and that the threshold value is not set by the setting processing unit 54 described below. , And so on.

  The control unit 5 also includes a setting processing unit 54, as shown in FIG. Specifically, the control unit 5 uses the CPU to execute the cleaning control program stored in the ROM. Thereby, the control unit 5 functions as the setting processing unit 54.

  The setting processing unit 54 sets the threshold value based on the light amount of the light L1 detected by the light detection unit 825 during the movement of the cleaning unit 82 when the cleaning process is executed according to the satisfaction of the second condition. Set.

  For example, when the cleaning unit 82 is moved in the transmission region R11 on the return path, the setting processing unit 54 uses the light detection unit 825 to detect the light amount of the light L1 at each time interval. Then, the setting processing unit 54 stores the light amount of the light L1 detected at each time interval in a predetermined storage area of the storage unit 7 in association with the division range corresponding to each time interval. Thus, the threshold value is set.

  The setting processing unit 54 may set the threshold value based on the light amount of the light L1 detected by the light detection unit 825 while the cleaning unit 82 is moving in the outward path.

[Threshold setting process]
Hereinafter, with reference to FIG. 7, an example of the procedure of the threshold setting process executed by the control unit 5 in the image forming apparatus 10 will be described. Here, steps S11, S12,... Show numbers of processing procedures (steps) executed by the control unit 5.

<Step S11>
First, in step S11, the control unit 5 determines whether or not the second condition is satisfied.

  Here, when the control unit 5 determines that the second condition is satisfied (Yes in S11), the control unit 5 shifts the processing to step S12. If the second condition is not satisfied (No side of S11), the control unit 5 waits for the satisfaction of the second condition in step S11.

<Step S12>
In step S12, the controller 5 executes the cleaning process.

[Cleaning process]
Here, an example of the procedure of the cleaning process executed in step S12 of the threshold setting process will be described with reference to FIG. The description of step S13 of the threshold value setting process will be given after the end of the description of the cleaning process.

<Step S21>
First, in step S21, the control unit 5 drives the light source 351A and the polygon mirror 352. Here, the process of step S21 is executed by the drive processing unit 52 of the control unit 5.

  Specifically, the control unit 5 causes the light source 351A to emit the reference light amount and rotates the polygon motor 353.

<Step S22>
In step S22, the control unit 5 starts the movement of the cleaning unit 82 in the outward path. Here, the process of step S22 is executed by the first drive control unit 51 of the control unit 5.

  Specifically, the control unit 5 rotates the motor 83 in the first direction to move the cleaning unit 82 from the home position P1 toward the folding position P2.

<Step S23>
In step S23, the control unit 5 determines whether or not the non-detection state in which the light L1 is not detected by the light detection unit 825 has continued beyond the first reference time.

  Here, when the control unit 5 determines that the non-detection state has continued beyond the first reference time (Yes in S23), the process proceeds to Step S24. If the non-detection state has not continued beyond the first reference time (No side of S23), the control unit 5 continues the non-detection state beyond the first reference time in step S23. Await.

<Step S24>
In step S24, the control unit 5 stops the movement of the cleaning unit 82 started in step S22. Here, the process of step S24 is executed by the second drive control unit 53 of the control unit 5.

<Step S25>
In step S25, the control unit 5 starts the movement of the cleaning unit 82 on the return path. Here, the process of step S25 is executed by the first drive control unit 51 of the control unit 5.

  Specifically, the control unit 5 rotates the motor 83 in the second direction to move the cleaning unit 82 from the folding position P2 toward the home position P1.

<Step S26>
In step S26, the control unit 5 uses the light detection unit 825 to detect the light amount of the light L1 at each time interval.

<Step S27>
In step S27, the control unit 5 determines whether or not the non-detection state in which the light L1 is not detected by the light detection unit 825 has continued beyond the second reference time.

  Here, when the control unit 5 determines that the non-detection state has continued beyond the second reference time (Yes in S27), the control unit 5 shifts the processing to Step S28. If the non-detection state has not continued beyond the second reference time (No side of S27), the control unit 5 continues the non-detection state beyond the second reference time in step S27. Await.

<Step S28>
In step S28, the control unit 5 stops the movement of the cleaning unit 82 started in step S25. Here, the process of step S28 is executed by the second drive control unit 53 of the control unit 5.

  With the above, the description of the cleaning process is ended, and the description of the threshold setting process is restarted.

<Step S13>
In step S13, the control unit 5 sets the threshold value. Here, the process of step S13 is executed by the setting processing unit 54 of the control unit 5.

  Specifically, the control unit 5 associates each of the light amounts of the light L1 detected at each of the time intervals during the execution of the cleaning process with the division range corresponding to each of the time intervals, and causes the storage unit 7 to store the light amount. Store in the storage area.

[Cleaning control processing]
Next, an example of the procedure of the cleaning control process executed by the control unit 5 in the image forming apparatus 10 will be described with reference to FIG.

<Step S31>
First, in step S31, the control unit 5 determines whether or not the first condition is satisfied.

  Here, when the control unit 5 determines that the first condition is satisfied (Yes in S31), the process proceeds to step S32. If the first condition is not satisfied (No side of S31), the control unit 5 waits for the satisfaction of the first condition in step S31.

<Step S32>
In step S32, the controller 5 executes the cleaning process (see FIG. 8).

<Step S33>
In step S33, the control unit 5 determines whether or not there is the division range in which the light amount of the light L1 detected by the light detection unit 825 in the cleaning process executed in step S32 is less than the threshold value.

  Here, if the control unit 5 determines that there is the division range in which the detected light amount of the light L1 is less than the threshold value (Yes in S33), the control unit 5 shifts the processing to step S34. Further, if the section range in which the detected light amount of the light L1 is less than the threshold does not exist (No side of S33), the control unit 5 shifts the processing to step S31.

<Step S34>
In step S34, the control unit 5 determines whether or not the number of executions of the cleaning process after it is determined in step S31 that the first condition is satisfied exceeds the upper limit number.

  Here, when the control unit 5 determines that the number of times the cleaning process has been executed exceeds the upper limit number (Yes in S34), the process proceeds to step S35. If the number of executions of the cleaning process does not exceed the upper limit number (No in S34), the controller 5 shifts the process to step S32.

<Step S35>
In step S35, the control unit 5 executes the light amount correction process. As a result, when the reduction of the light amount of the light L1 emitted from the light transmitting unit 359A is not improved by the execution of the cleaning process, that is, the reduction of the light amount of the light L1 emitted from the light transmitting unit 359A is caused by the light transmitting unit 359A. Even when the cause is other than the stain, it is possible to suppress the decrease in the light amount of the light L1 emitted from the light transmitting unit 359A.

  As described above, in the image forming apparatus 10, the cleaning unit 82 is provided with the light detection unit 825. Further, in the image forming apparatus 10, the light detection unit 825 is used to control the reciprocating movement of the cleaning unit 82. This simplifies the configuration used for controlling the movement of the cleaning unit 82, as compared with the configuration in which a sensor capable of detecting the presence or absence of the cleaning unit 82 is provided at each of the upstream end and the downstream end in the scanning direction D31 in the light transmitting unit 359A. It is possible to make it.

  Further, in the image forming apparatus 10, based on the light amount of the light L1 detected by the light detection unit 825 during the execution of the cleaning process using the cleaning unit 82, any one of the light amount correction process and the cleaning process again. One is executed. As a result, even if stains remain on the translucent portion 359A after the cleaning process is performed, it is possible to suppress a decrease in the amount of light L1 emitted from the translucent portion 359A due to the stain. is there.

  The cleaning unit 82 may be movable in the direction orthogonal to the scanning direction D31. Specifically, the cleaning unit 82, the contact unit 824, and the light detection unit 825 may be long provided in the scanning direction D31.

1 ADF
2 image reading unit 3 image forming unit 4 paper feeding unit 5 control unit 6 operation display unit 7 storage unit 8 cleaning mechanism 10 image forming apparatus 35 to 36 optical scanning device 51 first drive control unit 52 drive processing unit 53 second drive control Part 54 Setting processing part 81 Support part 82 Cleaning part 83 Motor 350 Housing 351A-351B Light source 352 Polygon mirror 359A-359B Translucent part 824 Contact part 825 Light detection part

Claims (10)

An optical scanning unit for scanning the light emitted from the light source,
A housing having a light transmitting portion through which the light scanned by the light scanning portion is transmitted;
It is provided movably along the scanning direction of the light by the light scanning unit while being in contact with the light transmitting unit outside the housing, and within the scanning range of the light by the light scanning unit in the light transmitting unit. A cleaning unit reciprocating in a drive range including each non-transmissive region outside the scanning range sandwiching the transmissive region;
A light detection unit provided in the cleaning unit, for detecting the light scanned by the light scanning unit;
A first drive control unit for starting the movement of the cleaning unit in each of the forward path and the return path;
A drive processing unit that drives the light source and the optical scanning unit during movement of the cleaning unit;
When the non-detection state in which the light is not detected by the light detection unit continues for a preset reference time after the first drive control unit starts the movement of the cleaning unit in each of the forward path and the backward path. A second drive control unit for stopping the movement of the cleaning unit;
An optical scanning device. The reference time is longer than the scanning period of the light by the light scanning unit,
The optical scanning device according to claim 1. The light detection unit is capable of detecting the light amount of the light scanned by the light scanning unit,
The optical scanning device corrects the light amount in the light emission control of the light source based on image data when the light amount of the light detected by the light detection unit during the movement of the cleaning unit is less than a predetermined threshold value. And a control unit that performs one or both of a light amount correction process and a cleaning process in which the cleaning unit reciprocates within the drive range.
The optical scanning device according to claim 1. The cleaning unit has a contact unit that contacts the light transmitting unit,
The light detection unit is provided on the downstream side in the moving direction in the outward path of the cleaning unit from the contact unit of the cleaning unit,
The control unit, when the light amount of the light detected by the light detection unit during the return path of the cleaning unit is less than the threshold value, performs one or both of the light amount correction process and the cleaning process. Run,
The optical scanning device according to claim 3. The second drive control unit cleans the cleaning unit when the non-detection state continues for a predetermined first reference time after the first drive control unit starts moving the cleaning unit on the outward path. When the non-detection state continues beyond the second reference time shorter than the first reference time after the movement of the section is stopped and the movement of the cleaning section on the return path by the first drive control section is started. Stopping the movement of the cleaning unit,
The optical scanning device according to claim 4. The control unit performs the cleaning when a predetermined first condition different from that the light amount of the light detected by the light detection unit during the movement of the cleaning unit on the return path is less than the threshold value is satisfied. When the light amount of the light detected by the light detection unit during the movement of the cleaning unit on the return path is less than the threshold value, the number of times of execution of the cleaning process after the satisfaction of the first condition is performed. On the basis of one of the light amount correction process and the cleaning process,
The optical scanning device according to claim 4. The control unit executes one of the light amount correction process and the cleaning process based on a difference in the light amount of the light detected by the light detection unit during each movement of the forward and backward paths of the cleaning unit. ,
The optical scanning device according to claim 4. The control unit performs the cleaning process when a predetermined cleaning condition different from that the light amount of the light detected by the light detection unit during the movement of the cleaning unit is less than the threshold value is satisfied. Then
The optical scanning device is configured to detect the light detected by the light detection unit during movement of the cleaning unit when the cleaning process is performed in accordance with satisfaction of a second predetermined condition among the cleaning conditions. A setting processing unit that sets the threshold value based on the light amount of
The control unit detects the light detection unit during movement of the cleaning unit when executing the cleaning process in response to satisfaction of a first condition different from the second condition among the cleaning conditions. Control whether or not to perform one or both of the light amount correction process and the cleaning process based on the light amount of light,
The optical scanning device according to any one of claims 3-5, and 7.   An image forming apparatus comprising the optical scanning device according to claim 1. An optical scanning unit for scanning light emitted from a light source, a housing having a light transmitting unit for transmitting the light scanned by the optical scanning unit, and the housing in contact with the light transmitting unit outside the housing. Each of the non-transmissive regions outside the scanning range is movably provided along the scanning direction of the light by the optical scanning unit and sandwiches a transmissive region within the scanning range of the light by the optical scanning unit in the translucent unit. A cleaning control method executed by an optical scanning device, comprising: a cleaning unit that reciprocates within a drive range; and a photodetector unit that is provided in the cleaning unit and that detects the light scanned by the optical scanning unit. hand,
Starting the movement of the cleaning section in each of the forward and return paths,
Driving the light source and the optical scanning unit while the cleaning unit is moving;
After moving in the forward and backward each of the cleaning unit is started, stop the movement of the cleaning unit when the non-detection state in which the light is not detected has continued beyond a preset reference time by the light detector To let
A cleaning control method including.

Images