Image forming apparatus

Abstract

A first supporting unit configured to movably support, in a direction intersecting with A length direction of A first reflecting mirror, an end of the first reflecting mirror in the length direction of the first reflecting mirror; a second supporting unit configured to movably support, in a direction intersecting with the length direction of a second reflecting mirror, an end of the second reflecting mirror in the length direction of the second reflecting mirror; a first drive source; a first transmission unit configured to transmit, when the first drive source provides a drive source in a first direction, the movement of the first drive source to a first supporting unit; and a second transmission unit configured to transmit, when the first drive source provides a drive source in a second direction, a movement of a second drive source to the second supporting unit.

What is claimed is: 
     
         1 . An image forming apparatus, comprising:
 an optical scanning unit provided with a polygon motor, the optical scanning unit being configured to generate a first scanning beam and a second scanning beam;   a first reflecting mirror having a first end and a second end in a length direction of the first reflecting mirror, the first end being fixedly supported, the second end being movably supported, the first reflecting mirror being configured to guide the first scanning beam to a first scan position;   a second reflecting mirror having a first end and a second end in a length direction of the second reflecting mirror, the first end being fixedly supported, the second end being movably supported, the second reflecting mirror being configured to guide the second scanning beam to a second scan position;   a first photoconductive drum configured to form a first latent image by the first scanning beam, the first scanning beam scanning at the first scan position;   a second photoconductive drum configured to form a second latent image by the second scanning beam, the second scanning beam scanning at the second scan position;   an image forming unit configured to form a first toner image and a second toner image by developing each of the first latent image and the second latent image with a toner and to form an image on a sheet by transferring the first toner image and the second tone image to the sheet;   a first cam configured to movably support the second end of the first reflecting mirror;   a second cam configured to movably support the second end of the second reflecting mirror;   a first motor configured to rotate in a first direction and in a second direction, a rotational direction of the first motor being switched between the first direction and the second direction;   a first gear train configured to be capable of transmitting a drive force from the first motor to the first cam and the second cam; and   a first clutch provided in the first gear train, the first clutch being configured to allow the first cam to move by transmission of the drive force of the first motor and to allow the second cam to stop by non-transmission of the drive force in a case where the first motor rotates in the first direction, the first clutch being configured to allow the second cam to move by transmission of the drive force and to allow the first cam to stop by non-transmission of the drive force in a case where the first motor rotates in the second direction.   
     
     
         2 . The image forming apparatus according to  claim 1 , wherein
 the first cam is supported rotatablely around a rotational axis parallel to a rotational axis of the polygon motor, the first cam being supported such that a contacting position of the first cam with respect to the first reflecting mirror moves in a direction orthogonal to the rotational axis of the first cam in a case where the first cam is driven via the first gear train by the first motor; and   the second cam is supported rotatablely around a rotational axis parallel to the rotational axis of the polygon motor, the second cam being supported such that a contacting position of the second cam with respect to the second reflecting mirror moves in a direction orthogonal to the rotational axis of the second cam in a case where the second cam is driven via the first gear train by the first motor.   
     
     
         3 . The image forming apparatus according to  claim 1 , wherein
 each of the first cam and the second cam comprises:   a shaft section rotated by the first gear train; and   a cam surface, wherein a distance between the cam surface and a central axis of the shaft section varies in a circumferential direction.   
     
     
         4 . The image forming apparatus according to  claim 3 , wherein
 the distance varies in proportion to a rotation angle of the shaft around the central axis.   
     
     
         5 . The image forming apparatus according to  claim 1 , wherein
 the first clutch is equipped with a one-way clutch.   
     
     
         6 . The image forming apparatus according to  claim 1 , wherein
 the optical scanning unit further generates a third scanning beam and a fourth scanning beam;   the image forming apparatus further comprises:   a third reflecting mirror having a first end and a second end in a length direction of the third reflecting mirror, the first end being fixedly supported, the second end being movably supported, the third reflecting mirror being configured to guide the third scanning beam to a third scan position;   a fourth reflecting mirror having a first end and a second end in a length direction of the fourth reflecting mirror, the first end being fixedly supported, the second end being movably supported, the fourth reflecting mirror being configured to guide the fourth scanning beam to a fourth scan position;   a third photoconductive drum configured to form a third latent image by the third scanning beam, the third scanning beam scanning at the third scan position;   a fourth photoconductive drum configured to form a fourth latent image by the fourth scanning beam, the fourth scanning beam scanning at the fourth scan position;   a third cam configured to movably support the second end of the third reflecting mirror;   a fourth cam configured to movably support the second end of the fourth reflecting mirror;   a second motor configured to rotate in a first direction and in a second direction, a rotational direction of the second motor being switched between the first direction and the second direction;   a second gear train configured to be capable of transmitting a drive force from the second motor to the third cam and the fourth cam; and   a second clutch provided in the second gear train, the second clutch being configured to allow the third cam to move by transmission of a drive force of the second motor and to allow the fourth cam to stop by non-transmission of the drive force in a case where the second motor rotates in the first direction, the second clutch being configured to allow the fourth cam to move by transmission of the drive force and to allow the third cam to stop by non-transmission of the drive force in a case where the second motor rotates in the second direction, wherein   the image forming unit is configured to further form a third toner image and a fourth toner image by developing each of the third latent image and the fourth latent image with a toner and to form an image on a sheet by transferring the first toner image, the second toner image, the third toner image, and the fourth toner image to the sheet.   
     
     
         7 . The image forming apparatus according to  claim 1 , wherein
 the first reflecting mirror is the reflecting mirror nearest to the first scan position in an optical path of the first scanning beam; and   the second reflecting mirror is the reflecting mirror nearest to the second scan position in an optical path of the second scanning beam.   
     
     
         8 . The image forming apparatus according to  claim 1 , wherein
 a movement direction of the first cam in a case where the first motor rotates in the first direction is opposite to a movement direction of the second cam in a case where the first motor rotates in the second direction.   
     
     
         9 . A method for image forming, the method comprising:
 preparing an image forming apparatus, the image forming apparatus comprising: an optical scanning unit provided with a polygon motor, the optical scanning unit being configured to generate a first scanning beam and a second scanning beam; a first reflecting mirror having a first end and a second end in a length direction of the first reflecting mirror, the first end being fixedly supported, the second end being movably supported, the first reflecting mirror being configured to guide the first scanning beam to a first scan position; a second reflecting mirror having a first end and a second end in a length direction of the second reflecting mirror, the first end being fixedly supported, the second end being movably supported, the second reflecting mirror being configured to guide the second scanning beam to a second scan position; a first photoconductive drum configured to forma first latent image by the first scanning beam, the first scanning beam scanning at the first scan position; a second photoconductive drum configured to form a second latent image by the second scanning beam, the second scanning beam scanning at the second scan position; an image forming unit configured to form a first toner image and a second toner image by developing each of the first latent image and the second latent image with a toner and to form an image on a sheet by transferring the first toner image and the second tone image to the sheet; a first cam configured to movably support the second end of the first reflecting mirror; a second cam configured to movably support the second end of the second reflecting mirror; a first motor configured to rotate in a first direction and in a second direction, a rotational direction of the first motor being switched between the first direction and the second direction; a first gear train configured to be capable of transmitting a drive force from the first motor to the first cam and the second cam; and a first clutch provided in the first gear train, the first clutch being configured to allow the first cam to move by transmission of the drive force of the first motor and to allow the second cam to stop by non-transmission of the drive force in a case where the first motor rotates in the first direction, the first clutch being configured to allow the second cam to move by transmission of the drive force and to allow the first cam to stop by non-transmission of the drive force in a case where the first motor rotates in the second direction;   adjusting a position of at least one of the second end of the first reflecting mirror and the second end of the second reflecting mirror by driving the first motor; and   forming an image on a sheet by using the image forming apparatus.