JP2008009319A - Laser scanning optical device - Google Patents

Abstract

A laser scanning optical apparatus having a simple configuration and capable of being manufactured at low cost is obtained.
A laser scanning optical apparatus comprising a light source that emits laser light, a deflector that deflects the laser light, and an optical element 4a (4b) that guides the deflected laser light onto a surface to be scanned. The elastic member 6 for pressing and fixing the optical element 4a (4b) is engaged with the elastic member fixing portion (locking portion) 51 of the support column 52 provided in the housing 15 by fitting the engaging hole 64 to the housing. It is attached to the body 15. At this time, the distal end portion 63 of the elastic member 6 presses and closes the opening 50 of the housing 15. Further, by inserting the optical element 4 a (4 b) between the elastic member 6 and the support column 53 of the housing 15, the optical element 4 a (4 b) is pressed and fixed by the protrusion 65 of the portion 61.
[Selection] Figure 2

Description

  The present invention relates to a laser scanning optical apparatus, and more particularly to a laser scanning optical apparatus mounted on an image forming apparatus such as a digital copying machine.

  Conventionally, as this type of laser scanning optical device, the one described in Patent Document 1 is known. In this laser scanning optical device, a gap between the optical element and the casing is closed with an elastic member in order to prevent dust from entering from the opening of the casing. Furthermore, another elastic member is provided to press the optical element.

However, since the laser scanning optical device has a wide range for closing the opening of the housing, the elastic member becomes large, and further, an elastic member different from the elastic member that presses the optical element is required, so that the cost is high. It had the problem of being attached.
JP 11-142769 A

  Accordingly, an object of the present invention is to provide a laser scanning optical apparatus that has a simple configuration and can be manufactured at low cost.

In order to achieve the above object, a laser scanning optical device according to the present invention includes:
A light source that generates laser light, a deflector that deflects the laser light, and an optical element that guides the deflected laser light onto the surface to be scanned,
The opening of the housing that houses the light source, the deflector, and the optical element is closed by an elastic member that presses and fixes the optical element at a predetermined position;
It is characterized by.

  In the laser scanning optical device according to the present invention, since the opening of the housing is closed by the elastic member that presses the optical element, the opening of the housing is sealed with one relatively small elastic member, and The optical element is fixed. Therefore, the laser scanning optical device has a simple configuration and can be manufactured at low cost.

  In the laser scanning optical device according to the present invention, for example, a plate spring is used as the elastic member. The opening of the housing is a hole or the like formed when the elastic member fixing portion is formed when the housing is resin-molded. Further, by pressing and fixing the optical element on one end side of the elastic member and pressing and closing the opening of the casing on the other end side, it becomes difficult to transmit each pressing force to the other.

  The elastic member connects the portion that presses the optical element and the portion that closes the opening of the housing with the portion having relatively low mechanical strength, so that stress concentrates on the portion having low mechanical strength. Therefore, a stable pressing force can be obtained between the portion that presses the optical element and the portion that closes the opening of the housing.

  Further, the elastic member makes it difficult to transmit each pressing force to the other by making the pressing direction of the portion that presses the optical element substantially perpendicular to the pressing direction of the portion that closes the opening of the housing.

  Embodiments of a laser scanning optical apparatus according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram of a laser scanning optical device 20. The laser scanning optical device 20 includes a laser diode 1 as a light source, first optical elements 2a and 2b (collimator lens 2a and cylindrical lens 2b), a deflector 3, and a second optical element (scanning lens) 4a. , 4b, an elastic member 6 that presses the second optical elements 4a, 4b, and a housing 15 that houses these components 1-4a, 4b.

  The laser light L emitted from the laser diode 1 passes through the first optical elements 2a and 2b, is reflected by the deflector 3 that is rotationally driven at a predetermined speed, and is deflected at an equiangular speed. Further, the laser beam L passes through the second optical elements 4a and 4b, forms an image on a scanning surface (photosensitive member surface) (not shown), and is scanned linearly. Although not shown, an optical element such as a mirror that bends the optical path of the laser light L is also arranged.

  As shown in FIG. 2A, a leaf spring is used as the elastic member 6 for fixing the second optical elements 4a and 4b. The elastic member 6 includes a fixing portion 60 provided with an engagement hole 64, a portion 61 that presses the second optical element 4a (4b), and a portion 63 that closes an opening 50 (described later) of the housing 15. The portion 62 has a relatively low mechanical strength and a U-shaped curved portion 66. The fixed portion 60 and the portion 61 that presses the second optical element 4a (4b) are opposed to each other with the curved portion 66 interposed therebetween. The portion 61 is formed with a hemispherical protrusion 65 protruding outward. The portion 61 that presses the second optical element 4a (4b) and the portion 63 that closes the opening 50 of the housing 15 are connected by a portion 62 that has relatively low mechanical strength.

  As shown in FIG. 2B, the elastic member 6 having the above configuration is fitted with the elastic member fixing portion (locking portion) 51 of the support column 52 provided in the housing 15 with the engagement hole 64. Is attached to the housing 15. At this time, the distal end portion 63 of the elastic member 6 presses and closes the opening 50 of the housing 15. The opening 50 of the housing 15 is a hole made in the trace of the core portion forming the elastic member fixing portion (locking portion) 51 when the housing 15 is resin-molded.

  Further, by inserting the second optical element 4 a (4 b) between the elastic member 6 and the column 53 of the housing 15, the second optical element 4 a (4 b) is pressed by the protrusion 65 of the portion 61. And fix.

  With the above configuration, the opening 50 of the housing 15 is closed by the elastic member 6 that presses the second optical element 4a (4b), so the opening of the housing 15 is formed by one relatively small elastic member 6. 50 can be sealed and the second optical element 4a (4b) can be fixed. Therefore, the laser scanning optical device 20 can be manufactured at a low cost.

  Further, in the elastic member 6, a portion 61 that presses the second optical element 4 a (4 b) and a portion 63 that closes the opening 50 of the housing 15 are connected by a portion 62 that has relatively low mechanical strength. The stress concentrates on the portion 62 having a low mechanical strength. Therefore, a stable pressing force can be obtained between the portion 61 that presses the second optical element 4a (4b) and the portion 63 that closes the opening 50 of the housing 15.

  Further, in the elastic member 6 </ b> A shown in FIG. 3, a portion 63 that closes the opening 50 of the housing 15 is connected to a fixing portion 60 provided with an engagement hole 64. The elastic member 6 </ b> A is attached to the housing 15 by fitting the engagement hole 64 to the elastic member fixing portion (locking portion) 51 of the support column 52 provided in the housing 15. At this time, the portion 63 of the elastic member 6 </ b> A presses and closes the opening 50 of the housing 15.

  Further, by inserting the second optical element 4a (4b) between the elastic member 6A and the support column 53 of the housing 15, the second optical element 4a (4b) is pressed by the protrusion 65 of the portion 61. And fix.

  The elastic member 6 </ b> A having the above configuration has the same effects as the elastic member 6. Further, the second optical element 4a (4b) is pressed and fixed by the portion 61 on one end side of the elastic member 6A, and the opening 50 of the housing 15 is pressed and closed by the portion 63 on the other end side. Thus, it becomes difficult for each pressing force to be transmitted to the other, and a pressing force that is more stable to each other can be obtained.

  In the elastic member 6 </ b> B shown in FIG. 4, a portion 63 that closes the opening 50 of the housing 15 is connected to a fixing portion 60 provided with an engagement hole 64 via a curved portion 67. The elastic member 6 </ b> B is attached to the housing 15 by fitting the engagement hole 64 to the elastic member fixing portion (locking portion) 51 of the support column 52 provided in the housing 15. At this time, the portion 63 of the elastic member 6B presses and closes the opening 50 of the housing 15.

  Further, by inserting the second optical element 4a (4b) between the elastic member 6B and the column 53 of the housing 15, the second optical element 4a (4b) is pressed by the protrusion 65 of the portion 61. And fix.

  The elastic member 6 </ b> B having the above configuration has the same effects as the elastic member 6. Furthermore, the curved portion 67 of the elastic member 6 </ b> B can arbitrarily change the pressing force of the portion 63 that closes the opening 50 of the housing 15. Accordingly, the degree of sealing can be improved by pressing the opening 50 of the housing 15 with an optimal pressing force.

  Further, in the elastic member 6B, the pressing direction of the portion 61 that presses the second optical element 4a (4b) and the pressing direction of the portion 63 that closes the opening 50 of the housing 15 are substantially orthogonal to each other. It becomes difficult to transmit the pressing force to the other. As a result, mutually stable pressing forces can be obtained. The same applies to the elastic members 6 and 6A and the elastic member 6C described below.

  Also, the elastic member 6C shown in FIG. 5 corresponds to the second optical element 4a (4b) that is fixed at an inclination of approximately 45 degrees. By changing the angle of the opening 50 of the housing 15 according to the pressing direction of the portion 61 that presses the second optical element 4a (4b), the second optical element 4a (4b) of the portion 61 that presses the second optical element 4a (4b) is changed. The pressing direction and the pressing direction of the portion 63 that closes the opening 50 of the housing 15 are substantially orthogonal.

  The laser scanning optical device according to the present invention is not limited to the above-described embodiments, and can be variously modified within the scope of the gist thereof.

  In particular, the configuration and arrangement of the optical system of the light source unit and the optical system that scans the laser light are arbitrary. The elastic member may not only press and fix the lens, but may also press and fix the mirror.

The top view which shows schematic structure of a laser scanning optical apparatus. An elastic member is shown, (A) is an external appearance perspective view, (B) is sectional drawing which shows the state which the elastic member is pressing the optical element. Sectional drawing which shows the state which another elastic member is pressing the optical element. Sectional drawing which shows the state which another elastic member is pressing the optical element. Sectional drawing which shows the state which another elastic member is pressing the optical element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laser diode 3 ... Deflector 4a, 4b ... 2nd optical element 6, 6A, 6B, 6C ... Elastic member 15 ... Case 20 ... Laser scanning optical apparatus 50 ... Opening part 51 ... Fixed part for elastic members (engagement) Stop)
61: a portion that presses the optical element 62 ... a portion that has relatively low mechanical strength 63 ... a portion that blocks the opening of the housing

Claims (6)

A light source that generates laser light, a deflector that deflects the laser light, and an optical element that guides the deflected laser light onto the surface to be scanned,
An opening of a housing that houses the light source, the deflector, and the optical element is closed by an elastic member that presses and fixes the optical element at a predetermined position;
A laser scanning optical device.   The laser scanning optical apparatus according to claim 1, wherein the elastic member is a leaf spring.   3. The laser scanning optical device according to claim 1, wherein the opening of the housing is a hole formed when the elastic member fixing portion is formed in the housing. 4.   The said elastic member presses the said optical element in the one end part side, and has blocked the opening part of the said housing | casing in the other end part side. Laser scanning optical device.   5. The elastic member is characterized in that a portion that presses the optical element and a portion that closes the opening of the housing are connected by a portion that has relatively low mechanical strength. The laser scanning optical apparatus according to any one of the above.   6. The elastic member according to claim 1, wherein a pressing direction of a portion that presses the optical element is substantially orthogonal to a pressing direction of a portion that closes the opening of the housing. A laser scanning optical device according to claim 1.

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