JP6459522B2 - Optical scanning device and image forming apparatus - Google Patents

Description

  The present invention relates to an optical scanning apparatus that forms an electrostatic latent image on a photosensitive drum, and an image forming apparatus.

  Conventionally, an optical scanning device that forms an electrostatic latent image on a photosensitive drum is known. In such an optical scanning device, an optical scanning device that adjusts the interval between light sources that emit a plurality of beams is disclosed (see Patent Document 1).

  In the optical scanning device described in Patent Document 1, the semiconductor laser control board is fixed to the device casing, and the holding unit is held by the device casing so as to be rotatable about the optical axis of the semiconductor laser. The semiconductor laser control board and the semiconductor laser are connected by applying a conductive material having viscosity.

  Patent Document 1 describes that according to this optical scanning device, the interval between light sources having two or more beams in one package can be adjusted with high accuracy.

JP 2006-171121 A

  However, in the optical scanning device described in Patent Document 1, the semiconductor laser control board is fixed to the device housing with four screws, and the distance between the light sources varies depending on the fixing method of the four screws. There is a fear. For example, depending on the order in which four screws are fixed, the semiconductor laser control board may rotate with respect to the apparatus housing, and the pitch in the sub-scanning direction may be shifted.

  SUMMARY An advantage of some aspects of the invention is that it provides an optical scanning device and an image forming apparatus capable of appropriately fixing a semiconductor laser to a housing.

  The optical scanning device of the present invention is an optical scanning device that forms an electrostatic latent image on a photosensitive drum, and includes a semiconductor laser, a laser holder, a housing, and two fixing bolts. The semiconductor laser irradiates a beam. The laser holder holds the semiconductor laser. The case houses a member constituting the optical scanning device. The two fixing bolts fix the laser holder to the casing. The housing includes two bolt holes into which the two fixing bolts are respectively screwed. The two fixing bolts are formed so that the screwing directions into the two bolt holes are opposite to each other.

  An image forming apparatus of the present invention is an image forming apparatus that forms an image on a recording medium, and includes the optical scanning device.

  According to the optical scanning device and the image forming apparatus of the present invention, the semiconductor laser can be appropriately fixed to the casing.

1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. It is a figure which shows the structure of the exposure part shown in FIG. It is a perspective view which shows the specific structure of the exposure part shown in FIG. It is a disassembled perspective view which shows the specific structure of the light source part shown in FIG. It is A view (front view) of the light source part shown in FIG. It is BB sectional drawing of the light source part shown in FIG. It is a rear view of the light source part shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings (FIGS. 1 to 7). In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof is not repeated.

  First, an image forming apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a configuration of an image forming apparatus 100 according to the present embodiment. Here, the image forming apparatus 100 is a multi-function peripheral (MFP). The image forming apparatus 100 has functions of a scanner, a copier, a printer, and a facsimile. The image forming apparatus 100 includes an image forming unit 1, an image reading unit 2, a document transport unit 3, and an operation panel 4.

  The image forming unit 1 forms an image on a recording sheet P that is an example of a recording medium. The image reading unit 2 reads an image formed on a document. The document transport unit 3 transports a document to be read. The operation panel 4 includes a touch panel 41 and receives an operation from the user for the image forming apparatus 100.

  The image forming unit 1 includes a paper feed cassette 11, a paper feed roller 12, a transport roller pair 13, a registration roller pair 14, an image forming unit 15, a fixing device 16, a discharge roller pair 17, and a discharge tray 18. The paper feed cassette 11 stores recording paper P in a stacked manner. The paper feed roller 12 feeds the recording paper P from the paper feed cassette 11 one by one. The recording paper P fed out by the paper feed roller 12 is conveyed to the image forming unit 15 by the conveyance roller pair 13 and the registration roller pair 14.

  The image forming unit 15 forms an image on the recording paper P conveyed from the paper feed cassette 11. The image forming unit 15 includes a photosensitive drum 151, a charging unit 152, an exposure unit 5, a developing unit 154, a transfer roller 155, and a cleaning unit 156. The exposure unit 5 corresponds to an “optical scanning device”. The photosensitive drum 151 is a cylindrical rotating body, and an electrostatic latent image is formed on the peripheral surface thereof. The charging unit 152 charges the photosensitive drum 151 to a predetermined potential. The exposure unit 5 irradiates the photosensitive drum 151 with laser light based on the image data, thereby forming an electrostatic latent image corresponding to the image data on the photosensitive drum 151. As the image data, for example, image data generated by the image reading unit 2 reading a document, or image data received from an external computer via a communication network (not shown) is used. The recording paper P on which the image is formed by the image forming unit 15 is conveyed to the fixing device 16.

  The developing unit 154 supplies toner to the electrostatic latent image formed on the photosensitive drum 151 and develops it, thereby forming a toner image on the photosensitive drum 151. The transfer roller 155 transfers the toner image on the photosensitive drum 151 onto the recording paper P. The cleaning unit 156 removes residual toner remaining on the photosensitive drum 151 after the transfer.

  The fixing device 16 thermally fixes the image formed on the recording paper P to the recording paper P. The fixing device 16 includes a heating roller containing a heating element and a pressure roller. The heating roller and the pressure roller form a fixing nip portion by being pressed against each other. As the recording paper P passes through the fixing nip portion, the toner adhering to the surface of the recording paper P is heated and melted, and the toner image is fixed on the recording paper P. The recording paper P on which the toner image is fixed is discharged to the discharge tray 18 by the discharge roller pair 17.

  Next, the configuration of the exposure unit 5 shown in FIG. 1 will be described with reference to FIGS. FIG. 2 is a diagram showing a configuration of the exposure unit 5 shown in FIG. FIG. 3 is a perspective view showing a specific configuration of the exposure unit 5 shown in FIG. 2 and 3, the exposure unit 5 includes a light source unit 51, a collimating lens 52, a first aperture 53, a cylindrical lens 54, a second aperture 55, a polygon mirror 56, an f-θ lens 57, and a BD sensor 58. And a housing 59.

  The light source unit 51 outputs a laser beam having a light amount corresponding to a drive current supplied from a laser control unit (not shown). The collimating lens 52 converts the laser light output from the light source unit 51 into parallel light. The first aperture 53 and the second aperture 55 shape the laser beam converted into parallel rays into a desired beam spot diameter.

  The cylindrical lens 54 forms an image of parallel light on the reflection surface of the polygon mirror 56. The polygon mirror 56 has a plurality of reflection surfaces (in this embodiment, five) that reflect incident light toward the photosensitive drum 151, and, for example, in the direction of the arrow in FIG. It rotates at a constant speed (clockwise in FIG. 2).

  The f-θ lens 57 forms an image of the laser beam reflected by the polygon mirror 56 in a spot shape having a predetermined diameter on the peripheral surface of the photosensitive drum 151. The BD sensor 58 is provided in a laser beam scanning region at a position away from the end of the photosensitive drum 151 by a predetermined distance. When receiving the laser beam, the BD sensor 58 outputs a detection signal indicating that the laser beam has been received to the laser control unit.

  As shown in FIG. 3, the housing 59 houses the collimating lens 52, the first aperture 53, the cylindrical lens 54, the second aperture 55, the polygon mirror 56, the f-θ lens 57, and the BD sensor 58. In FIG. 3, the light source unit 51 is disposed at the right end of the housing 59.

  Next, the configuration of the light source unit 51 will be described with reference to FIGS. FIG. 4 is an exploded perspective view showing a specific configuration of the light source unit 51 shown in FIG. FIG. 5 is an A view (front view) of the light source unit 51 shown in FIG. 3. 6 is a BB cross-sectional view of the light source unit 51 shown in FIG. FIG. 7 is a rear view of the light source unit 51 shown in FIG.

  As shown in FIG. 4, the light source unit 51 includes a semiconductor laser 511, a laser holder 512, a fixing bolt 513, a circuit board 514, and a screw 515. The housing 59 is formed with a holder support plate 591, a laser light transmission hole 592, and a bolt hole 593.

  The holder support plate 591 is a plate-like member that supports the laser holder 512. The laser light transmission hole 592 is a hole through which the laser beam emitted from the semiconductor laser 511 passes. The bolt hole 593 is a hole in which a female screw that is screwed into the fixing bolt 513 is formed on the inner surface thereof.

  The semiconductor laser 511 is, for example, an LD (Laser Diode), and irradiates two beams with one chip in this embodiment. In the present embodiment, a case where two beams are irradiated with one chip will be described. However, one beam may be irradiated with one chip, or three or more beams may be irradiated with one chip.

  As the number of beams emitted from one chip increases, the image forming speed can be increased. On the other hand, when there are a plurality of beams emitted from one chip, it is necessary to adjust the interval (pitch) of the laser beams.

  The laser holder 512 holds the semiconductor laser 511. The laser holder 512 includes a boss 512a, a long hole 512b, a holding hole 512c, and a screw hole 512d. The boss 512 a is inserted into a boss hole 514 a formed in the circuit board 514, and fixes the circuit board 514 to the laser holder 512.

  Two long holes 512b are formed at both ends in the longitudinal direction of the laser holder 512, and two fixing bolts 513 are inserted therethrough. The holding hole 512c allows the semiconductor laser 511 to be inserted from the housing 59 side of FIG. 4 to the circuit board 514 side and fixed (see FIG. 6). The screw hole 512d is a hole into which the screw 515 is inserted.

  The fixing bolt 513 fixes the laser holder 512 to the housing 59. Specifically, the fixing bolt 513 is inserted into the elongated hole 512b from the circuit board 514 side of FIG. 4 toward the housing 59 and is screwed into the bolt hole 593 formed in the housing 59. A female screw is formed on the inner peripheral surface of the bolt hole 593. In addition, the two fixing bolts 513 are twisted in the two bolt holes 593 in opposite directions. For example, the fixing bolt 513a on the left side in FIG. 5 is a left-hand thread, and the fixing bolt 513b on the right side in FIG. 5 is a right-hand thread.

  As shown in FIG. 5, the long hole 512b of the laser holder 512 is formed outside the lower portion of the circuit board 514. Therefore, after the circuit board 514 is attached to the laser holder 512, the fixing bolt 513 is attached to the paper surface of FIG. Can be tightened from the front side. Therefore, the light source unit 51 can be easily assembled.

  As described above, when the two fixing bolts 513 are screwed into the corresponding bolt holes 593, the screwing directions into the two bolt holes 593 are opposite to each other. The torque applied to the laser holder 512 is reversed. Therefore, the laser holder 512 can be fixed to the housing 59 at a desired angle. Therefore, the interval (pitch) of laser beams can be easily adjusted. In other words, the semiconductor laser 511 can be appropriately fixed to the housing 59.

  In this embodiment, the case where there are two fixing bolts 513 will be described, but it is sufficient that the number of fixing bolts 513 is two or more. For example, when there are four fixing bolts 513, the two fixing bolts arranged on the left side in FIG. 5 are left-handed screws, and the two fixing bolts arranged on the right side in FIG. And it is sufficient.

  In addition, the two long holes 512b are formed in such a manner that the two fixing bolts 513 are inserted into the two long holes 512b and screwed into the two bolts 594, respectively, and the laser holder 512 is centered on the holding hole 512c. It is comprised so that rotation is possible. For example, as shown in FIG. 5, the laser holder 512 can be rotated in the direction indicated by the arrow RT.

  As described above, since the laser holder 512 is configured to be rotatable, after the laser holder 512 is rotated and adjusted to an appropriate position, the two fixing bolts 513 are respectively twisted onto the two bolts 594. The laser holder 512 can be fixed to the housing 59. Therefore, the semiconductor laser 511 can be more appropriately fixed to the housing 59.

  Further, the two fixing bolts 513 are configured to be visually identifiable. Specifically, the two fixing bolts 513 are different in at least one of color, shape, and size. For example, the head of the left fixing bolt 513a in FIG. 5 is painted in blue, and the head of the right fixing bolt 513b in FIG. 5 is painted in red.

  Thus, since the two fixing bolts 513 are configured to be visually identifiable, it is possible to prevent the left fixing bolt 513a and the right fixing bolt 513b from being mistaken. Therefore, assembly can be facilitated.

  In the present embodiment, the case where the colors of the two fixing bolts 513 are different from each other has been described. However, it is sufficient that at least one of the colors, shapes, and dimensions of the two fixing bolts 513 is different. For example, the two fixing bolts 513 may have different shapes. Specifically, for example, a plus-shaped groove corresponding to a plus driver is formed in the head of the left fixing bolt 513a in FIG. 5, and a minus driver is provided in the head of the right fixing bolt 513b in FIG. A minus-shaped groove corresponding to is formed.

  Further, for example, the two fixing bolts 513 may have different dimensions. Specifically, for example, the diameter of the head of the left fixing bolt 513a in FIG. 5 is 8.3 mm, and the diameter of the head of the right fixing bolt 513b in FIG. 5 is 6.3 mm. Form may be sufficient. Further, for example, the shaft portion of the left fixing bolt 513a in FIG. 5 may be formed with a diameter of 4 mm, and the shaft portion of the right fixing bolt 513b in FIG. 5 may be formed with a diameter of 3 mm.

  As shown in FIG. 4, the circuit board 514 controls the driving of the semiconductor laser 511. A boss hole 514a and a screw groove 514b are formed in the circuit board 514. The boss 512 a of the laser holder 512 is inserted into the boss hole 514 a of the circuit board 514, and the circuit board 514 is fixed to the laser holder 512.

  As shown in FIG. 5, the screw grooves 514b are formed at both lower ends of the circuit board 514, and the shafts of the screws 515 are fitted therein. The screw 515 is fitted into the screw groove 514 b of the circuit board 514 and is inserted into the screw hole 512 d of the laser holder 512, and the circuit board 514 is fixed to the laser holder 512.

  As shown in FIG. 6, the head of the semiconductor laser 511 is fixed to the holding hole 512 c of the laser holder 512, and the legs of the semiconductor laser 511 are inserted into the holding holes 512 c of the laser holder 512. 514c is inserted.

  As shown in FIG. 7, the long hole 512b formed in the laser holder 512 is formed in a substantially arc shape with the center of the holding hole 512c formed in the laser holder 512 as the center position. In FIG. 7, the illustration of the fixing bolt 513 is omitted for convenience.

  Next, an assembly procedure of the light source unit 51 will be described with reference to FIG. First, the semiconductor laser 511 is inserted into the holding hole 512c of the laser holder 512 and fixed. Next, the boss 512a of the laser holder 512 is inserted into the boss hole 514a of the circuit board 514 and temporarily fixed. Then, the screw 515 is fitted into the screw groove 514 b of the circuit board 514 and is inserted into the screw hole 512 d of the laser holder 512 and fixed. As a result, the circuit board 514 is fixed to the laser holder 512.

  Next, the fixing bolt 513 is inserted into the long hole 512 b of the laser holder 512 and is slightly screwed into the bolt hole 593 formed in the housing 59. Then, the fixing bolt 513 is slid in the long hole 512b of the laser holder 512, and the laser holder 512 is rotated in the direction of the arrow RT in FIG. 5 to adjust the interval (pitch) of the laser light. Then, two fixing bolts 513 are simultaneously tightened into the bolt holes 593 formed in the casing 59 while the laser holder 512 is fixed at an appropriate position by hand, and the light source unit 51 is fixed to the casing 59.

  As described above, the light source unit 51 can be fixed at an appropriate position.

  The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof (for example, (1) to (4) shown below). In order to facilitate understanding, the drawings schematically show each component as a main component, and the thickness, length, number, and the like of each component shown in the drawings are different from the actual for convenience of drawing. . Moreover, the shape, dimension, etc. of each component shown by said embodiment are an example, Comprising: It does not specifically limit, A various change is possible in the range which does not deviate substantially from the structure of this invention.

  (1) Although the case where the image forming apparatus 100 is a multifunction peripheral has been described in the present embodiment, any apparatus including the image forming unit 1 may be used. For example, the image forming apparatus may be a printer or a copier.

  (2) In this embodiment, the case where the circuit board 514 is fixed to the laser holder 512 on the side opposite to the housing 59 has been described. However, the circuit board 514 may be configured to be fixed to the laser holder 512. . For example, the circuit board 514 may be disposed between the housing 59 and the laser holder 512.

  (3) In this embodiment, the case where the circuit board 514 and the laser holder 512 are fixed by the screws 515 and the bosses 512a has been described. However, the circuit board 514 and the laser holder 512 may be fixed in other directions. For example, the circuit board 514 and the laser holder 512 may be fixed by screws or may be fixed by screws or bolts.

  (4) In the present embodiment, the case where the laser holder 512 and the housing 59 are fixed by the fixing bolt 513 has been described. However, the laser holder 512 and the housing 59 may be fixed by screws.

  The present invention can be used in an optical scanning device that forms an electrostatic latent image on a photosensitive drum and an image forming apparatus.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 1 Image forming unit 15 Image forming part 151 Photosensitive drum 152 Charging part 154 Developing part 16 Fixing device 5 Exposure part (optical scanning device)
51 Light Source 511 Semiconductor Laser 512 Laser Holder 512a Boss 512b Long Hole 512c Holding Hole (Holding Part)
512d Screw hole 513 Fixing bolt 513a First fixing bolt 513b Second fixing bolt 514 Circuit board 514a Boss hole 514b Screw groove 514c Foot hole 515 Screw 52 Collimating lens 53 First aperture 54 Cylindrical lens 55 Second aperture 56 Polygon mirror 57f θ lens 58 BD sensor 59 Case 591 Holder support plate 592 Laser light transmission hole 593 Bolt hole

Claims (6)

An optical scanning device for forming an electrostatic latent image on a photosensitive drum,
A semiconductor laser for irradiating the beam;
A laser holder for holding the semiconductor laser;
A housing for housing members constituting the optical scanning device;
Two fixing bolts for fixing the laser holder to the housing;
A circuit board for driving the semiconductor laser;
A screw for fixing the circuit board to the laser holder;
The housing includes two bolt holes into which the two fixing bolts are respectively screwed,
The two fixing bolts are formed so that the screwing directions into the two bolt holes are opposite to each other.
The circuit board is fixed to the laser holder on the opposite side of the housing,
The circuit board has a notch hole-like screw groove formed at the end of the notch for fastening the boss hole and the fixing bolt ,
The laser holder has a boss and a screw hole,
The boss of the laser holder is inserted into the boss hole of the circuit board,
An optical scanning device, wherein the screw shaft is fitted into the screw groove of the circuit board, the screw is inserted into a screw hole of the laser holder, and the circuit board is fixed to the laser holder.   The optical scanning device according to claim 1, wherein the semiconductor laser irradiates a plurality of beams with one chip.   The optical scanning device according to claim 1, wherein the two fixing bolts are configured to be visually distinguishable.   The optical scanning device according to claim 3, wherein the two fixing bolts are different in at least one of color, shape, and size. The laser holder is
A holding part for holding the semiconductor laser in a substantially central part;
Two long holes through which the two bolts are inserted, respectively, at both ends in the longitudinal direction,
The two long holes are formed so that the laser holder rotates around the holding portion in a state where the two bolts are inserted into the two long holes and screwed into the two bolt holes, respectively. The optical scanning device according to claim 1, wherein the optical scanning device is configured to be movable. An image forming apparatus for forming an image on a recording medium,
An image forming apparatus comprising the optical scanning device according to claim 1.

Images