JP4529979B2 - Optical scanning device - Google Patents

Description

  The present invention relates to an optical scanning device in which a light source is attached to a frame via a holder.

  In general, as an image forming apparatus, an electrostatic latent image is formed on a photosensitive drum by scanning a charged photosensitive drum with a light beam by an optical scanning device, and a developer is supplied to the electrostatic latent image. A developer image formed by transferring a developer image onto a sheet is known.

  Conventionally, an optical scanning device provided in such an image forming apparatus includes an LD holder for supporting a laser diode that emits a light beam (see Patent Document 1). Specifically, the LD holder includes a bottom wall and a vertical wall standing upward from the bottom wall, and has a structure in which the laser diode is held by the vertical wall. The LD holder is fixed to the frame by screwing the bottom wall to the bottom wall of the frame.

JP 2004-163463 A

  However, in the conventional structure, since the bottom wall of the LD holder and the bottom wall of the frame are screwed, the screw protrudes from the bottom wall of the frame. Therefore, it is necessary to provide a space having a size corresponding to the length of the screw on the lower side of the bottom wall of the frame, and this space has been an obstacle to downsizing.

  Therefore, an object of the present invention is to reduce the size of the optical scanning device by preventing the protrusion of the screw outside the frame.

In order to solve the above problems, an optical scanning device according to the present invention includes a frame having a bottom wall, a light source that emits a light beam in a direction along the bottom wall of the frame, and a cup that collects the light beam emitted from the light source. A ring lens, a deflection mirror that performs scanning by changing a reflection direction of a light beam that has passed through the coupling lens, a scanning lens that forms an image on a medium to be imaged with the light beam scanned by the deflection mirror, A base that is erected from the bottom wall into the frame and has a screw hole at the top; a screw that is screwed into the screw hole; a first wall that is fixed to the base with the screw; and the first A first holding member having a second wall extending from a wall toward the bottom wall and supporting the light source; and a second holding member that is attached to the frame via the first holding member and holds the coupling lens. a holding member, Wherein the second holding member in a bottom wall of said frame in a portion facing, wherein the first opening is formed.

According to the present invention, the base on which the first wall of the first holding member is screwed is erected from the bottom wall of the frame toward the inside of the frame. It is possible to prevent the protrusion. For this reason, a space for escaping a screw conventionally provided on the lower side of the bottom wall of the frame becomes unnecessary, and the optical scanning device can be miniaturized. In addition, since the second holding member that holds the coupling lens faces the first opening formed in the bottom wall of the frame, the coupling lens can be opened from the first opening even after the assembly of the optical scanning device is completed. Can be easily adjusted. Furthermore, since the position adjustment of the coupling lens is facilitated in this way, the degree of freedom of the shape of the optical element such as the coupling lens and each component increases, so the optical scanning device can be reduced in size without degrading the optical performance. Can be realized.

According to the present invention, since the base for screwing the first holding member is erected from the bottom wall of the frame toward the inside, it is possible to prevent the screw from protruding to the outside of the frame. Can be miniaturized. In addition, since the second holding member faces the first opening, the position of the coupling lens can be easily adjusted from the first opening even after the assembly of the optical scanning device is completed. Furthermore, since the position adjustment of the coupling lens is facilitated in this way, the degree of freedom of the shape of the optical element such as the coupling lens and each component increases, so the optical scanning device can be reduced in size without degrading the optical performance. Can be realized.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a perspective view showing an optical scanning device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing each component of the optical scanning device and a light route. First, the overall structure of the optical scanning device 1 will be briefly described with reference to FIGS. 1 and 2.

[Optical scanning device 1]
As shown in FIG. 1, the optical scanning device 1 includes a light source unit 10, a first mirror M1, a vibrating mirror unit 20, a first scanning lens 30 as a scanning optical system lens, a second scanning lens L, It mainly includes a second mirror M2, a frame 40 that supports them, and a third mirror M3 (see FIG. 2) disposed below the frame 40.

[Light source unit 10]
As shown in FIG. 2, the light source unit 10 includes a laser diode 11 as an example of a light source, and a coupling lens 12 that collects a light beam emitted from the laser diode 11. The light source unit 10 includes a diaphragm member 13 as an example of a regulating member that regulates the light flux width of the light beam that has passed through the coupling lens 12, and a cylindrical lens 14 that focuses the light beam focused by the diaphragm member 13 in one direction. I have. Then, the laser beam (light beam) emitted from the laser diode 11 passes through the coupling lens 12, the diaphragm member 13, and the cylindrical lens 14, is reflected by the first mirror M <b> 1, and is irradiated toward the vibrating mirror unit 20. The

[Vibration mirror unit 20]
The oscillating mirror unit 20 includes an oscillating mirror 21 as an example of a deflection mirror that scans by changing the reflection direction of the light beam emitted from the first mirror M1 side by rotating and oscillating within a predetermined range. It is prepared for. The light reflected by the oscillating mirror 21 passes through the first scanning lens 30 and the second scanning lens L, is then reflected by the second mirror M2 and the third mirror M3, and is emitted to the outside of the optical scanning device 1. Is done. The light beam emitted out of the optical scanning device 1 is imaged on the image forming medium. For example, a light beam emitted out of the optical scanning device 1 is projected onto a photosensitive member (photosensitive drum or the like) in an image forming apparatus such as a copying machine or a laser printer, thereby forming an electrostatic latent image on the photosensitive member. Contribute to.

  Next, the details of the mounting structure of the light source unit 10 will be described. In the drawings to be referred to, FIG. 3 is a perspective view showing an attachment structure of a light source unit, and FIG. 4 is a perspective view showing a first holding member and an eccentric cam. FIG. 5 is a perspective view showing the third holding member, and FIG. 6 is a plan view showing each opening formed in the frame. In the following description, the directions shown in FIG.

[Details of frame 40]
As shown in FIG. 1, the frame 40 is formed in a tray shape mainly including a bottom wall 41 and an outer peripheral wall 42. As shown in FIG. 3, a partition wall 43, a holding member boss 44, a cam boss 45, and a positioning projection 46 are mainly formed in a portion of the frame 40 where the light source unit 10 is disposed. .

  The partition wall 43 mainly includes a front wall 43a, a left wall 43b, and a right wall 43c. With these walls 43a to 43c, the light source unit 10 (specifically, a first wall of the first holding member 15 described later). 15a) is partially enclosed. And the positioning rib 43d which protrudes back is formed in the appropriate position of the front wall 43a along the up-down direction. The upper edge of the positioning rib 43d is formed in a taper shape.

  The holding member boss 44 is a cylindrical boss that is erected upward from the inner bottom wall 41 of the partition wall 43, and an inner surface of which is a screw for screwing a screw N (see FIG. 1). It is a hole 44a. Further, a total of three holding member bosses 44 are provided, and all three of them are arranged so as not to be aligned in a straight line, thereby supporting the first holding member 15 described later at three points. . The screw hole 44a may be a hole in which a screw groove is formed in advance, or may be a hole in which the screw groove is cut by the screw N simultaneously with the screw N being screwed.

  The cam boss 45 is a cylindrical boss formed lower than the holding member boss 44, and an inner surface thereof is a screw hole 45 a for attaching an eccentric cam 50 described later. The cam boss 45 is disposed rearward of the three holding member bosses 44.

  The positioning projection 46 is a columnar projection that is erected upward from the bottom wall 41 inside the partition wall 43, and the lower side is formed as a large-diameter portion 46 a and the upper side is larger than the large-diameter portion 46 a. Is also formed as a small diameter portion 46b having a small diameter. The height of the large diameter portion 46 a is lower than each holding member boss 44.

  The bottom wall 41 of the frame 40 is formed with a first opening 41a and a second opening 41b (see FIG. 6) penetrating vertically. The details of the first opening 41a and the second opening 41b will be described later.

[Details of the light source unit 10]
As shown in FIGS. 4 and 5, the light source unit 10 includes a first holding member 15 that holds the laser diode 11, a second holding member 16 that holds the coupling lens 12, a second holding member 16, and an aperture member 13. And a third holding member 17 for supporting the. The cylindrical lens 14 that is a component of the light source unit 10 is fixed at a suitable position of the frame 40.

  As shown in FIG. 4, the first holding member 15 is made of sheet metal, and includes a first wall 15 a that is disposed substantially horizontally and a second wall 15 b that extends downward from the first wall 15 a. .

  The first wall 15a has three through holes 15c that match the screw holes 44a of the holding member bosses 44 of the frame 40 at appropriate positions, and fits with the small diameter portion 46b of the positioning projection 46 of the frame 40. A joint hole 15d is provided. Further, an engagement groove 15e that engages with a positioning rib 43d formed on the partition wall 43 of the frame 40 is formed on the right side of the front end edge of the first wall 15a. And the 1st wall 15a comprised in this way is fixed to the boss | hub 44 for holding members of the flame | frame 40 with the screw | thread N shown in FIG.

  The second wall 15b is a long wall extending back and forth along the bottom wall 41 of the frame 40. The front end of the second wall 15b is connected to the front side of the left end edge of the first wall 15a, and the laser diode 11 is connected to the other end. Is attached. Here, the laser diode 11 is arranged so that the optical axis of the emitted light beam is substantially perpendicular to the second wall 15 b and the emitted light beam is along the bottom wall 41 of the frame 40. Therefore, the second wall 15 b is configured to be able to bend and deform in the optical axis direction of the light beam emitted from the laser diode 11.

  A long hole 15f along the vertical direction (a direction substantially orthogonal to the horizontal plane of the light beam emitted from the laser diode 11 and slightly tilted from the vertical direction) is formed in a substantially central portion of the second wall 15b. In addition, a notch 15g is formed at the upper and lower edges of the long hole 15f. Further, a predetermined through hole 15 h is formed between the long hole 15 f and the laser diode 11. The through hole 15 h is a screw hole for fixing an electronic board (not shown) on which a circuit associated with the laser diode 11 is mounted to the holder 15.

  Further, the second wall 15b is formed with an engagement piece 15i extending rightward at the rear end thereof and engaging with the eccentric cam 50, and at the front end thereof above the through hole 15c on the front side of the first wall 15a. A bending arm 15j is formed so as to go around. A long hole 15k having a width substantially the same as the diameter of the through hole 15c of the first wall 15a is formed at the tip of the bending arm 15j. For this reason, the bending arm 15j is fixed to the frame 40 together with the first wall 15a, thereby increasing the rigidity of the front side of the long hole 15f of the second wall 15b, so that the vicinity of the long hole 15f can be positively bent. it can.

  The eccentric cam 50 has a cam surface 51 formed so that the distance from the rotation center gradually changes. The eccentric cam 50 is rotatable with respect to a screw 52 disposed along the vertical direction, and thereby rotates about an axis along a direction substantially orthogonal to the bottom wall 41 of the frame 40. It is possible to move. The eccentric cam 50 is fixed to the cam boss 45 at the head of the screw 52 by screwing the male screw portion 53 of the screw 52 into the cam boss 45 of the frame 40.

  The eccentric cam 50 configured as described above is rotatable when the screw 52 is temporarily fixed to the cam boss 45. In such a rotatable state, the cam surface 51 of the eccentric cam 50 is engaged with the engaging piece 15 i of the first holding member 15, and the eccentric cam 50 is appropriately centered on the screw 52 in a predetermined direction. , The rear end side of the second wall 15b is pressed in the direction of the optical axis via the engagement piece 15i and moves to the left. Further, by rotating the eccentric cam 50 in the direction opposite to the predetermined direction, the rear end side of the second wall 15b moves to the right by elastic deformation.

  As shown in FIG. 5, the second holding member 16 includes a main body portion 16a formed in a rectangular plate shape extending in the vertical direction, and a pair of protrusions protruding forward and rearward from the front and rear ends of the upper portion of the main body portion 16a. The portion 16b (only one is shown) is formed in a substantially T shape. An attachment hole 16c for attaching the coupling lens 12 is formed at the lower portion of the main body portion 16a of the second holding member 16, and a positioning piece 13d formed at the lower end of the diaphragm member 13 at the lower end thereof. A fitting groove 16d for fitting is formed. Further, a through hole 16e penetrating left and right is formed at the lower rear corner of the main body 16a.

  The throttle member 13 is substantially T-shaped by a main body portion 13a formed in a substantially rectangular thin plate shape extending in the vertical direction and a pair of protrusion portions 13b protruding forward and rearward from the front and rear ends of the upper portion of the main body portion 13a. It is formed in a shape. The main body 13a of the diaphragm member 13 is formed with a slit 13c for restricting the beam width of the light beam at the lower portion thereof, and a positioning piece 13d extending rightward at the lower end thereof. Specifically, the positioning piece 13d is formed to gradually narrow from the lower end of the main body portion 13a to a predetermined position on the right side, and is formed to extend with the same width after the predetermined position. And the part formed in this same width is fitted in the fitting groove 16d of the second holding member 16, so that the diaphragm member 13 and the second holding member 16 are positioned in the front-rear direction. It has become.

  The third holding member 17 is made of sheet metal and has an upper wall 17a that is disposed substantially horizontally, and a pair of support walls 17b that extend downward from the upper wall 17a and support the diaphragm member 13 and the second holding member 16 described above. It is configured with.

  The upper wall 17a is fitted with the through hole 17c that matches two of the three through holes 15c formed in the first wall 15a of the first holding member 15, and the small diameter portion 46b of the positioning projection 46 of the frame 40. A fitting hole 17d to be mated and an engaging groove 17e to be engaged with a positioning rib 43d formed in the partition wall 43 of the frame 40 are formed.

  The support wall 17b has a fitting groove 17f into which the protruding portion 13b of the throttle member 13 is fitted, and an engaging groove 17g wider than the protruding portion 16b on which the protruding portion 16b of the second holding member 16 is placed. Is formed. Therefore, the diaphragm member 13 is fixed to the support wall 17b, but the second holding member 16 is movable in the left-right direction (optical axis direction), and the position adjustment in the left-right direction is possible.

  The 3rd holding member 17 comprised as mentioned above is attached so that it may cover from the 1st holding member 15 as shown in FIG. When the third holding member 17 is mounted on the first holding member 15 as described above, the coupling lens 12 supported by the second holding member 16 is placed on the optical axis of the laser diode 11 as shown in FIG. Placed in. Although illustration of the diaphragm member 13 is omitted, the diaphragm member 13 is also disposed on the optical axis of the laser diode 11 in the same manner.

  Further, when the first holding member 15 and the third holding member 17 are attached to the frame 40 in this way, the second holding member 16 faces the first opening 41 a formed in the bottom wall 41 of the frame 40. The second wall 15b of the first holding member 15 (specifically, the portion holding the laser diode 11) faces the second opening 41b. Therefore, even after the first holding member 15 and the third holding member 17 are assembled to the frame 40, the coupling lens 12 supported by the second holding member 16 and the laser diode 11 supported by the first holding member 15. From the openings 41a and 41b.

According to the above, the following effects can be obtained in the present embodiment.
Since the holding member boss 44 is erected from the bottom wall 41 of the frame 40 toward the inside as a base for screwing the first holding member 15, it is possible to prevent the screw from protruding outside the frame 40. Thus, the optical scanning device 1 can be downsized.

  Since the second wall 15b of the first holding member 15 is configured to be able to bend and deform in the optical axis direction, the position of the laser diode 11 can be adjusted in the optical axis direction. Further, the second wall 15b is formed in a long shape extending along the bottom wall 41 of the frame 40, and a long hole 15f and a cutout portion 15g along the vertical direction are formed in a substantially central portion of the second wall 15b. Therefore, the second wall 15b is easily bent, and the position adjustment of the laser diode 11 is facilitated.

  Since the eccentric cam 50 that presses the second wall 15b is rotatable about an axis along a direction orthogonal to the bottom wall 41 of the frame 40, a jig or a hand can be moved into the frame 40 from above. It is possible to adjust the position of the laser diode 11 by inserting it. Therefore, for example, the position of the laser diode 11 can be easily adjusted as compared with a structure in which a jig or the like is inserted from the opening on the side of the frame to adjust the position.

  Further, since the position of the laser diode 11 is adjusted by pressing the end portion of the second wall 15b with the eccentric cam 50, the laser diode 11 becomes difficult to shift in directions other than the optical axis, and the position adjustment becomes accurate. By the way, in the conventional structure that adjusts the position of the laser diode by screwing a screw so that it penetrates through the plate to which the laser diode is fixed and the wall of the frame and moving the plate integrally with the screw against the wall, If the laser diode is deformed under the influence of the rotation of the screw, the laser diode may be displaced in a direction other than the optical axis.

  In addition, in the conventional structure in which the position is adjusted by inserting a screwdriver or the like from the opening on the side of the frame, it is necessary to place a laser diode near the side wall of the frame. In a structure in which the position of the laser diode can be adjusted, the laser diode can be provided at an arbitrary position on the frame.

Since the 1st holding member 15 consists of sheet metal, the manufacture becomes easy compared with a resin thing, for example.
Since the diaphragm member 13 and the second holding member 16 are positioned by the positioning piece 13d and the fitting groove 16d that are fitted to each other, the coupling lens 12 and the slit 13c can be positioned without the frame 40, and the cup A shift of the ring lens 12 and the slit 13c with respect to the optical axis center can be suppressed.

  Since the second holding member 16 that holds the coupling lens 12 faces the first opening 41 a formed in the bottom wall 41 of the frame 40, the first opening even after the assembly of the optical scanning device 1 is completed. The position of the coupling lens 12 can be easily adjusted from 41a. In addition, since the position adjustment of the coupling lens 12 is facilitated in this way, the degree of freedom in the shape of the optical elements such as the coupling lens 12 and the respective components is increased. 1 can be miniaturized.

  Since the second wall 15b of the first holding member 15 that holds the laser diode 11 faces the second opening 41b formed in the bottom wall 41 of the frame 40, even after the assembly of the optical scanning device 1 is completed, The position of the laser diode 11 can be easily adjusted from the second opening 41b. Further, since the position adjustment of the laser diode 11 is facilitated in this way, the degree of freedom in the shape of the optical elements such as the coupling lens 12 and the respective components is increased. Can be reduced in size.

In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below.
In the above-described embodiment, the three cylindrical holding member bosses 44 are used as the base, but the present invention is not limited to this. For example, the base bulges upward from the bottom wall of the frame, and a plurality of screws are formed at the top. You may employ | adopt the bulging part etc. in which the hole was formed.

In the above-described embodiment, the vibrating mirror 21 is used as the deflection mirror. However, the present invention is not limited to this, and for example, a polygon mirror may be used.
In the above embodiment, the second wall 15b is bent downward from the first wall 15a and then has a long shape along the bottom wall 41. However, the present invention is not limited to this, and the second wall is the first wall. The shape may be simply bent downward from the wall.

In the said embodiment, although the 1st holding member 15 and the 3rd holding member 17 were formed with the sheet metal, this invention is not limited to this, For example, you may form with resin etc.
In the above embodiment, the aperture member 13 is provided with the positioning piece 13d and the second holding member 16 is provided with the fitting groove 16d. However, the present invention is not limited to this, and the relationship between the positioning piece and the fitting groove is reversed. It may be. Moreover, as a fitting structure, you may employ | adopt the structure which fitted the pin and the hole, the structure which meshed | combined the comb-shaped thing, etc.

1 is a perspective view showing an optical scanning device according to an embodiment of the present invention. It is the schematic which shows each component and optical route of an optical scanning device. It is a perspective view which shows the attachment structure of a light source unit. It is a perspective view which shows a 1st holding member and an eccentric cam. It is a perspective view which shows a 3rd holding member. It is a top view which shows each opening part formed in the flame | frame.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical scanning device 10 Light source unit 11 Laser diode 12 Coupling lens 13 Diaphragm member 13c Slit 13d Positioning piece 15 1st holding member 15a 1st wall 15b 2nd wall 15f Long hole 15g Notch 15i Engagement piece 16 2nd holding Member 16d fitting groove 40 frame 41 bottom wall 41a first opening 41b second opening 44 holding member boss 44a screw hole 45 cam boss 45a screw hole 50 eccentric cam N screw

Claims (9)

A frame having a bottom wall;
A light source that emits a light beam in a direction along the bottom wall of the frame;
A coupling lens that collects the luminous flux emitted from the light source;
A deflection mirror that scans by changing the reflection direction of the light beam that has passed through the coupling lens;
A scanning lens that forms an image of a light beam scanned by the deflection mirror on an imaging medium;
A base that is erected from the bottom wall of the frame into the frame and has a screw hole at the top;
A screw screwed into the screw hole;
A first holding member having a first wall fixed to the base with the screw, and a second wall extending from the first wall toward the bottom wall and supporting the light source;
A second holding member that is attached to the frame via the first holding member and holds the coupling lens ;
An optical scanning device characterized in that a first opening is formed in a portion of the bottom wall of the frame where the second holding member faces .   The optical scanning device according to claim 1, wherein the base is a cylindrical boss. 3. The optical scanning device according to claim 1, wherein the second wall of the first holding member is configured to be able to bend and deform in an optical axis direction of a light beam emitted from the light source. 4. The second wall of the first holding member is formed in an elongated shape extending along the bottom wall, the light source is attached to one end, and the first wall is connected to the other end. The optical scanning device according to claim 3. The long hole extended in the direction substantially orthogonal to the horizontal surface of the said light beam is formed between the one end part and the other end part of the 2nd wall of the said 1st holding member, The Claim 4 characterized by the above-mentioned. Optical scanning device. The said 1st holding member consists of sheet metal, The any one of Claims 1-5 characterized by the above-mentioned.
The optical scanning device according to Item. An eccentric cam capable of pressing the second wall of the first holding member in the optical axis direction;
The optical scanning device according to any one of claims 3 to 6, wherein the eccentric cam is rotatable about an axis along a direction orthogonal to the bottom wall. . Attached to the frame via the first holding member, further comprising a regulating member for regulating the light flux width of the light beam passing through the coupling lens,
The optical scanning device according to claim 1, wherein the restricting member and the second holding member are positioned by a fitting portion that is fitted to each other. The second wall is opposed portions of the first holding member in the bottom wall of the frame, according to any one of claims 1 to 8, characterized in that the second opening is formed Optical scanning device.

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