JP2008185724A - Mounting structure of scanning optical lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the mounting structure of a scanning optical lens which prevents light from being blocked off by a leaf spring. <P>SOLUTION: A first scanning lens 30 is provided with: a long convex face part 31a which projects in a circular arc-shape; a second back face part 32b which is located at the opposite side of the convex face part 31a and is brought into contact with a frame 40; convex face side flat face parts 32a formed in a flat plane on both ends of the convex face part 31a; and an upper face part 31c and a lower face part 31d which connect the convex face part 31a, the second back face part 32b, and the convex face side flat face parts 32a. Further, the leaf spring 50 has: a first extended part 51 which extends from the side of the second back face part 32b of the first scanning lens 30 to the side of the convex face side flat face part 32a; a second extended part 52 which extends from the other end part of the first extended part 51 to a lower side; and a third extended part 53 which extends from the second extended part 52 to the outside in the longitudinal direction of the convex face part 31a, then is bent to the opposite side and brought into contact with the convex face side flat face part 32a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a scanning optical system lens mounting structure for mounting a scanning optical system lens to a frame using a leaf spring.

  In general, as an image forming apparatus, a charged photosensitive drum is irradiated with a light beam from an optical scanning device, and an electrostatic latent image is formed on the photosensitive drum by changing the potential of the portion irradiated with the light beam. There is known a technique in which a developer image formed by supplying a developer to an electrostatic latent image is transferred to a sheet to form a predetermined image on the sheet.

  In an optical scanning device provided in such an image forming apparatus, a scanning optical system lens (hereinafter referred to as “lens”) having a long convex surface protruding in an arc shape is usually provided. As such a lens mounting structure, a structure as disclosed in Patent Document 1 is conventionally known. Specifically, in the mounting structure disclosed in Patent Document 1, both ends of the convex portion of the lens are brought into contact with columnar protrusions formed on the frame, and a flat rear surface opposite to the convex portion is formed on the plate. The lens is fixed to the frame by pressing with a spring.

JP 7-168110 A

  By the way, depending on the arrangement of various parts on the frame, there is a case where it is desired to reverse the relation between the leaf spring and the protrusion in the above-described technique, that is, to press the convex surface portion of the lens with the leaf spring. However, in this case, there is a possibility that light that is incident from the back surface of the lens and passes through the convex surface side is blocked by the leaf spring.

  Accordingly, an object of the present invention is to provide a scanning optical lens mounting structure that can prevent light from being blocked by a leaf spring.

  The present invention for solving the above problems is a scanning optical lens mounting structure in which a scanning optical system lens is mounted on a frame using a leaf spring, and the scanning optical system lens is a long convex surface protruding in an arc shape. Part, a rear surface part that is located on the opposite side of the convex surface part, and at least both end parts are in contact with the frame, a convex surface side flat part that is formed flat at both ends of the convex surface part, the convex surface part, A pair of planar portions connecting the back surface portion and the convex-surface-side planar portion, and the plate spring has one end fixed to the frame and the other end facing one of the pair of planar portions. A first extending portion extending from the back surface side of the system lens to the convex surface portion side; a second extending portion extending from the other end portion of the first extending portion toward the other side of the pair of plane portions; It extends from the second extension part to the outside in the longitudinal direction of the convex part. After, characterized in that a third extending portion which is in contact with the convex side planar portion is bent to the opposite side.

  According to the present invention, the third extending portion that supports the scanning optical system lens extends outward in the longitudinal direction of the convex surface portion and then bends to the opposite side, so that the light emitted from the convex surface portion extends to the third portion. It is not blocked at the part.

  According to the present invention, by providing the third extending portion that extends from the second extending portion to the outside in the longitudinal direction of the convex surface portion and then bends to the opposite side, the light emitted from the convex surface portion and the third extending portion are provided. Interference with the part can be prevented, so that blocking of light by the leaf spring can be prevented. Moreover, interference with a convex surface part and a 2nd extension part can be prevented.

  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, a coupling lens 12, a diaphragm member 13, and a cylindrical lens 14. The laser beam emitted from the laser diode 11 passes through the coupling lens 12, the diaphragm member 13, and the cylindrical lens 14, is then reflected by the first mirror M <b> 1, and is irradiated toward the vibrating mirror unit 20.

[Vibration mirror unit 20]
The oscillating mirror unit 20 includes an oscillating mirror 21 that performs scanning by changing the reflection direction of light emitted from the first mirror M1 side by rotating and oscillating within a predetermined range. . 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 emitted to the outside of the optical scanning device 1 is projected onto a photoconductor (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 photoconductor. Contribute to.

  Next, the details of the mounting structure of the first scanning lens 30 will be described. In the drawings to be referred to, FIG. 3 is an exploded perspective view showing a mounting structure of a first scanning lens, and FIG. 4 is an enlarged perspective view showing a leaf spring.

  As shown in FIG. 1, the first scanning lens 30 is attached to the frame 40 using two leaf springs 50.

[First scanning lens 30]
As shown in FIG. 3, the first scanning lens 30 includes a lens portion 31 formed in an arc shape and attached portions 32 formed integrally at both ends of the lens portion 31.

  By forming the first scanning lens 30 in this way, the light emission side of the first scanning lens 30 is a long curved surface protruding in an arc shape toward the second scanning lens L side. A certain convex surface portion 31a and a convex surface side planar portion 32a formed in a planar shape at both ends of the convex surface portion 31a are formed. In addition, each convex surface side plane part 32a is formed so that it may become in the same plane (surface flush).

  Further, on the light incident side of the first scanning lens 30, a first back surface portion 31b having a curved surface parallel to the convex surface portion 31a and a second back surface portion 32b having a flat surface along each convex surface side flat surface portion 32a are provided. It is formed. In addition, each 2nd back surface part 32b is formed so that it may become in the same plane (surface flush).

  Further, on the upper side of the first scanning lens 30, an upper surface portion 31c that connects the upper edges of the convex surface portion 31a, the convex surface side flat surface portion 32a, the first back surface portion 31b, and the second back surface portion 32b is formed. A lower surface portion 31d that connects the lower edges of the convex surface portion 31a, the convex surface side flat surface portion 32a, the first back surface portion 31b, and the second back surface portion 32b is formed below the first scanning lens 30.

[Leaf spring 50]
As shown in FIG. 4, the leaf spring 50 includes a first extending part 51, a second extending part 52, a third extending part 53, and a frame attaching part 54.

  One end 51 a of the first extending portion 51 is fixed to the frame 40 via the frame mounting portion 54, and the other end 51 b faces the upper surface portion 31 c of the first scanning lens 30 and the first extending portion 51 of the first scanning lens 30. It is formed to extend from the second back surface portion 32b to the convex surface side flat surface portion 32a side. The first extending portion 51 has a main body portion 51c that is wider than the end portions 51a and 51b in the center, and a substantially rectangular long hole 51d is formed in the central portion of the main body portion 51c. A long fourth extending portion 51e is formed from a part of the inner edge of the long hole 51d. The fourth extending portion 51e is bent downward to a predetermined angle, and a hemispherical protrusion 51f that protrudes downward is formed at the tip. Therefore, the fourth extending portion 51e presses the upper surface portion 31c of the first scanning lens 30 with a predetermined pressing force by the projection 51f.

  The second extending portion 52 is formed so as to extend downward from the other end portion 51 b of the first extending portion 51. A third extending portion 53 is formed integrally with an edge portion 52 a on the outer side in the longitudinal direction of the first scanning lens 30 in the second extending portion 52. Here, the second extending part 52 is formed with the same width as the other end part 51 b formed narrower than the main body part 51 c of the first extending part 51, so that the light is emitted from the first scanning lens 30. The second extending portion 52 is positioned at a position sufficiently separated (emitted) from the light.

  The third extending portion 53 extends from the edge portion 52a of the second extending portion 52 to the outside in the longitudinal direction of the first scanning lens 30 and then bends to the opposite side, so that the tip 53a thereof is the first scanning lens 30. It comes in contact with the convex surface side flat portion 32a. Specifically, the third extending portion 53 is curved in an arc shape, and the tip 53a is formed to be tapered.

  The frame attachment portion 54 is formed so as to extend downward from the one end portion 51 a of the first extension portion 51. In addition, a long hole 54a extending in the vertical direction is formed at an appropriate position below the frame attachment portion 54. By fitting the long hole 54a with a rectangular protrusion formed in the frame 40, a leaf spring is formed. 50 is fixed to the frame 54. Further, a bent portion 54b is formed at the lower edge of the frame mounting portion 54 so as to be bent obliquely downward on the opposite side to the first extending portion 51, whereby the frame mounting portion 54 will be described later. It is suppressed from being caught by the connecting rib 44 (see FIG. 3) of the frame 40.

[Frame 40]
As shown in FIG. 3, a portion of the frame 40 to which the first scanning lens 30 is attached has a lower surface support rib 41 that supports the lower surface portion 31 d of the first scanning lens 30 and a second rear surface of the first scanning lens 30. A back support rib 42 that supports the portion 32b is formed. A pair of guide ribs 43 for guiding the leaf springs 50 are formed on the back side of the back support ribs 42 (the side opposite to the first scanning lens 30). A connecting rib 44 that connects the ribs 42 and 43 is formed between the back support rib 42 and the guide rib 43.

Next, a method for attaching the first scanning lens 30 to the frame 40 will be described.
As shown in FIG. 3, first, the first scanning lens 30 is set on the lower surface support rib 41 of the frame 40. At this time, the concave portions (not shown) formed in the lower surface portion 31d of the first scanning lens 30 are aligned with the convex portions 41a of the lower surface support rib 41, so that the front, rear, left, and right of the first scanning lens 30 can be simplified. Perform positioning.

  Then, the frame attachment portion 54 is inserted into the pair of guide ribs 43 while the tip 53 a of the third extending portion 53 of the leaf spring 50 is brought into contact with the convex surface side flat portion 32 a of the first scanning lens 30. After that, the leaf spring 50 is pushed into a predetermined position, and then the frame mounting portion 54 is fixed to the connecting rib 44, so that the first scanning lens 30 has the third extension portion 53 and the fourth extension portion 51e of the leaf spring 50. And is pressed and fixed to the frame 40 well.

According to the above, the following effects can be obtained in the present embodiment.
Since the third extending portion 53 does not jump out to the convex surface portion 31a side by extending the third extending portion 53 from the outside toward the convex surface side flat portion 32a, the leaf spring 50 (third extending portion) 53) can prevent light from being blocked. Further, by providing the third extending portion 53, the shape of the second extending portion 52 located on the convex surface portion 31a side of the first scanning lens 30 can be made to escape from light. Can be prevented.

In addition to the third extending portion 53 that applies a force in the lateral direction to the first scanning lens 30, the fourth extending portion 51 e that applies a force in the downward direction is provided, so that the first scanning lens 30 is made stronger. Can be fixed.
Since the tip 53a of the third extending portion 53 is tapered and contacts the convex surface side flat portion 32a, for example, it is pressed by a protrusion formed at a position away from the tip, such as the protrusion 51f of the fourth extending portion 51e. Compared with the structure to which it does, a member does not protrude from the part which is pressing down the convex surface side plane part 32a to the convex surface part 31a side, and it can achieve size reduction.

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 embodiment, the first scanning lens 30 is used as the scanning optical system lens. However, the present invention is not limited to this, and for example, the second scanning lens L may be used.

In the above embodiment, the first back surface portion 31b of the first scanning lens 30 is formed in a curved shape, but the present invention is not limited to this, and the first scanning lens 30 is formed in a flat shape so that the entire back surface of the first scanning lens is flat. May be.
In the said embodiment, although the 3rd extension part 53 was formed in the curved-surface shape curved in circular arc shape, this invention is not limited to this, For example, you may be bent in V shape etc. However, since it is easier to maintain the pressing force on the first scanning lens 30 when the third extending portion 53 is curved in an arc shape, it is desirable that the third extending portion 53 be formed in an arc shape.

In the said embodiment, although the 4th extension part 51e which presses the 1st scanning lens 30 from the top was provided, this invention is not limited to this, The 4th extension part 51e does not need to be provided.
In the said embodiment, although the front-end | tip of the 3rd extension part 53 was sharpened, this invention is not limited to this, It is good also as other shapes, for example, circular arc shape.
Although the vibrating mirror unit 20 is used in the embodiment, a polygon mirror may be used.

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 disassembled perspective view which shows the attachment structure of a 1st scanning lens. It is an expansion perspective view which shows a leaf | plate spring.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical scanning device 30 1st scanning lens 31 Lens part 31a Convex surface part 31b 1st back surface part 31c Upper surface part 31d Lower surface part 32 Mounted part 32a Convex surface side plane part 32b 2nd back surface part 40 Frame 50 Leaf spring 51 1st extension Part 51a One end part 51b The other end part 51c Main body part 51d Long hole 51e Fourth extending part 51f Projection 52 Second extending part 52a Edge part 53 Third extending part 53a Tip 54 Frame attaching part 54a Long hole 54b Bending part

Claims (4)

A scanning optical system lens mounting structure for mounting a scanning optical system lens to a frame using a leaf spring,
The scanning optical system lens is
A long convex surface protruding in an arc shape;
A back surface portion located on the opposite side to the convex surface portion, at least both ends of which contact the frame;
A convex-side planar portion formed in a planar shape at both ends of the convex-surface portion;
A pair of planar portions connecting the convex surface portion, the back surface portion and the convex surface side planar portion;
The leaf spring is
A first extension portion that has one end fixed to the frame and the other end extends from the back surface side of the scanning optical system lens to the convex surface side while facing one of the pair of flat surface portions;
A second extending portion extending from the other end portion of the first extending portion toward the other side of the pair of plane portions;
A scanning optical system comprising: a third extending portion that extends from the second extending portion to the outside in the longitudinal direction of the convex surface portion, and then bends to the opposite side to contact the convex surface side flat portion. Lens mounting structure.   The scanning optical system lens mounting structure according to claim 1, wherein the third extending portion is curved in an arc shape.   3. The scanning optical system lens according to claim 1, wherein the first extending portion is provided with a fourth extending portion that presses one of a pair of plane portions of the scanning optical system lens. 4. Mounting structure.   4. The scanning optical system lens attachment according to claim 1, wherein a tip of the third extending portion is formed in a tapered shape so as to contact the convex surface side plane portion. 5. Construction.

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