KR19990042846A - Gwangju Yarn Equipment - Google Patents

Abstract

According to the present invention, a beam emitted from a polygon mirror passes through an optical fiber bundle to form an image on a photosensitive drum, thereby forming a focal point. Therefore, it is not necessary to use a scanning lens that is difficult to process, thereby improving productivity and minimizing a product. In particular, it relates to a light source for emitting a laser beam; A condensing lens, a slit, and a focusing lens for focusing the beam emitted from the light source; A polygon mirror for deflecting the beam emitted from the focusing lens to a predetermined angle of view; An incident surface configured to have an arc shape so that the beam deflected from the polygon mirror is incident at a right angle; An optical fiber coupled to the incidence surface in a bundle to form a plurality of scanned beams into small spots; And the free end of the optical fiber bundle is characterized in that the exit surface is formed to be spaced apart from the entrance surface to form a focal point by the photosensitive drum.

Description

Gwangju Yarn Equipment

The present invention relates to an optical scanning device, and more particularly, by allowing a beam deflected in a polygon mirror to be imaged on a photosensitive drum by an optical fiber bundle without passing through a scanning lens, thereby reducing constraints on scanning width and resolution, and making it possible to reduce the thickness of the optical mirror. It relates to an optical scanning device.

In general, the optical device is provided with a rectangular housing (1) as shown in Figure 1 and is provided with a light source (2) with a built-in laser diode on one side of the housing (1). The light source 2 emits a beam toward the collimating lens 3 and parallel beams parallel to the horizontal main scanning direction and the vertical sub-scanning direction through the collimating lens 3. Is made. The parallel beam passes only the central portion of the beam while passing through the slit member 3a having a rectangular hole in the main scanning direction, and then converges in the sub scanning direction in the cylindrical lens 3b.

The beam converged in the sub-scanning direction is reflected by the polygon mirror 4 which is rotated at a high speed with a constant angle of view and exits to the scanning lens 5 which is an f-θ lens. The scanning lens 5 is composed of a toric lens and a focusing lens, and the incident beam converges in the main scanning direction to be emitted to the photosensitive drum 7. The emitted beam converges in the main scanning direction in the state of convergence in the sub-scanning direction, thereby forming a focus when incident on the photosensitive drum 7.

The optical scanning device configured as described above turns the beam emitted from the light source 2 through the collimating lens 3 into a parallel beam, and then the sub-scan while passing through the slit 3a and the cylindrical lens 3b. The beam in the direction converges. The beam converged in the sub-scanning direction is scanned from the polygon mirror 4 into the photosensitive drum 7 with a constant angle of view. Before the beam is scanned into the photosensitive drum 7, the main scanning direction is converged by the scanning lens 5, and when the beam is incident on the photosensitive drum 7, a focus is formed and a desired image is obtained.

However, the conventional scanning device is complicated in that two scanning lenses 5 must be used to converge the beam emitted from the polygon mirror 4. Since the two scanning lenses 5 are aspheric, they are difficult to process and have to be assembled with their optical axes coincident, and they have disadvantages such as limitations in scanning width or resolution.

SUMMARY OF THE INVENTION The present invention was developed in view of the conventional problems, and an object of the present invention is that a beam emitted from a polygon mirror passes through an optical fiber bundle to form an image on a photosensitive drum to form a focal point, thereby making it difficult to use a scanning lens that is difficult to process. As a result, it is possible to improve the productivity and to provide Gwangju-si which can be miniaturized.

1 is a perspective view of a conventional optical scanning device,

2 is a plan view of the present invention optical scanning device,

Figure 3 is a side view of the present optical scanning device.

<Description of Symbols for Main Parts of Drawings>

10 light source 11 condensing lens

12: Slit 13: Focusing Lens

14: polygon mirror 15: incident surface

16: optical fiber 17: exit surface

18: photodiode 19: photosensitive drum

The present invention to achieve the above object is a light source for emitting a laser beam; A condensing lens, a slit, and a focusing lens for focusing the beam emitted from the light source; A polygon mirror for deflecting the beam emitted from the focusing lens to a predetermined angle of view; An incident surface configured to have an arc shape so that the beam deflected from the polygon mirror is incident at a right angle; An optical fiber coupled to the incidence surface in a bundle to form a plurality of scanned beams into small spots; And the free end of the optical fiber bundle is characterized in that the exit surface is formed to be spaced apart from the entrance surface to form a focal point by the photosensitive drum.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a plan view of the optical scanning device of the present invention and Figure 3 is a side view of the optical scanning device of the present invention. A light source 10 for generating a laser beam of monochromatic light is provided, and a condensing lens 11 for converging the beam in front of the light source 10 is provided. In addition, the slit 12 and the focusing lens 13 are provided in front of the condensing lens 11, and the beam scanned by the focusing lens 13 is deflected to have a constant angle of view in the polygon mirror 14 at which the beam is rotated at high speed. . In addition, an incident surface 15 having an arc shape is provided in consideration of a change in the point of focus of the beam deflected in front of the polygon mirror 14 (change of the reflection angle when the beam is reflected by the polygon mirror). A plurality of optical fibers 16 are attached to the incident surface 15 in the form of bundles. These optical fibers 16 are perpendicular when coupled to the incident surface 15. Therefore, the beam scanned in the deflected state is incident perpendicularly to the incident surface 15 and then accurately scanned into each optical fiber 16.

An exit surface 17 is provided to be close to the photosensitive drum 19 while being spaced apart from the entrance surface 15 by a predetermined distance, and the free end of each bundle of optical fibers 16 coupled to the entrance surface 15 has an exit surface 17. ) Is combined. Therefore, an optical fiber bundle is formed between the entrance face 15 and the exit face 17. Part of the fiber bundle is used to detect the synchronization signal. That is, the optical fiber 16 coupled to one end of the incident surface 15 is extended to connect with the photodiode 18. In addition, the photodiode 18 may be directly coupled to one side end of the incident surface 15 so that the synchronization signal may be detected.

According to the present invention configured as described above, a laser beam of monochromatic light is emitted from the light source 10 and focused on the condensing lens 11. Then, the slit 12 or the pinhole is provided in the focusing part to remove the noise component due to the scattered light. The diffused beam forms a focal plane at a predetermined distance by the focusing lens 13, and a polygon mirror 14 for deflection is installed between the focusing lens 13 and the focal plane and scanned with the beam deflected. In addition, the beam scanned while being deflected is scanned to the incident surface 15 having an arc shape in consideration of the change of the object point by the reflection angle, and the beam is scanned to each of the bundle of optical fibers 16 coupled to the rear of the incident surface 15. The beam is scanned perpendicular to the incident surface 15 and then side by side with each optical fiber 16. Further, the beam passing through each optical fiber 16 is imaged on the photosensitive drum 19 in the form of a very small spot through the exit surface 17 to form an image.

As described above, according to the present invention, the effective scanning width and the resolution can be adjusted by arranging a plurality of optical fiber bundles and adjusting the optical fiber bundles appropriately. And there is an effect such that the length control of the optical fiber can be made small.

Claims (2)

A light source for emitting a laser beam; A condensing lens, a slit, and a focusing lens for focusing the beam emitted from the light source; A polygon mirror for deflecting the beam emitted from the focusing lens to a predetermined angle of view; An incident surface configured to have an arc shape so that the beam deflected from the polygon mirror is incident at a right angle; An optical fiber coupled to the incidence surface in a bundle to form a plurality of scanned beams into small spots; And an emission surface formed at a free end of the optical fiber bundle at a predetermined distance apart from the entrance surface to form a focal point with a photosensitive drum. The optical scanning device of claim 1, wherein the optical fiber through which the scanning start beam or the scanning completion beam passes through the optical fiber bundle is extended to a photodiode to detect a synchronization signal.