JPS60170823A - Light beam scanner - Google Patents

Abstract

PURPOSE:To facilitate adjustment and maintenance inspection by forming a signal optical element which functions as a reflecting mirror and a dustproof member, and incorporating this at such a proper position that a light beam is converged on a photosensitive body. CONSTITUTION:The light LB from a light source is deflected by each deflecting surface according to the rotation of a rotary polygon scanning mirror 1 and converged 2, then made incident on a prism type optical element 6 from an incidence surface 60 and reflected by a reflecting surface 61, and projected from a projection surface 62 through a projection window to illuminate a specific scanning line on the photosensitive drum 5. The prism type optical element 6 is so arranged as to reflect and bend the light beam LB by its reflecting surface 61 and also close the projection window 60 of the projection surface 62, thereby functioning as both the projection surface 62 and dustproof member. Consequently, the number of optical parts is decreased to reduce the trouble of adjustment, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to light beam feeding of sardines using laser printers, etc., and particularly to cost reduction and adjustment of equipment,
Concerning improvements to the structure of the chamber to facilitate maintenance and inspection.

[Conventional technique]

FIG. 1 is a 11111 view conceptually showing the configuration of a conventional light beam scanning device used in a laser printer, etc., which includes a rotating polygonal scanning mirror 1, a focusing lens 2, a reflecting mirror 3, a dustproof member 4, and a photoreceptor. It is configured to include at least a drum 5. In a scanning device having such a configuration, a light beam (laser light) LB irradiated from a light source (not shown) is deflected by one deflection surface of the rotating multifaceted scanning bell 1, and then deflected by the focusing lens 2.
The light passes through and enters the reflecting mirror 3, is reflected by the reflecting surface, passes through the dustproof member 4, and is irradiated onto the photosensitive drum 5. Here, the scanning of the light beam LB on the photosensitive drum 5 is performed based on the deflection for each deflection according to the rotation of the rotary multi-surface scanning mirror 1.
At this time, the focusing lens 2 functions to focus the light beam LB onto the photoreceptor drum 5, and the reflecting mirror 3 functions to focus the focused light beam LB onto the photoreceptor drum 5, as described above.
The function is to guide the photosensitive drum 5 onto the upper scanning line of the photosensitive drum 5 by reflection.

Further, the dustproof member 4, which is disposed so as to block the exit window 4o of the light beam LB after the reflection function of the reflection mirror 3, is configured by the above-mentioned components, and prevents external damage to the optical system. This is provided to perform the function of preventing dust from entering.

According to the conventional light beam scanning device, iL, the light beam LB
Since the reflecting mirror 3 and the dust-proofing member 4, which are required for scanning and the dust-proofing function of the optical system, were arranged separately, the number of optical parts increased due to changes in the device configuration. This has disadvantages in that it increases the cost of the device and complicates adjustment, maintenance and inspection.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and provides an original beam scanning device that can reduce the cost of the device and simplify adjustment and maintenance inspection by reducing the number of parts. The purpose is to

[Structure of the invention]

Therefore, in the present invention, a single optical element is created which has the functions of a reflecting mirror 3 and a dustproof member 4 that are required in the conventional device configuration, and this optical element is used to direct the light beam in the light beam scanning optical system to the photoreceptor. The above objective is achieved by incorporating the lens at a suitable position where it can be focused on the top.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 2 is a side view of a light beam scanning device showing an embodiment of the present invention. An incident surface 60 of the beam LB, a reflecting surface 61 . Injection surface 6
A single prism type optical element 6 having two three end faces is used. This prism-type optical element 6 has a reflective surface 61 interposed in the optical path through which the light beam LB passes, and an exit surface 62 of the prism-type optical element 6 which is located at an exit window 4 for the light beam LB.
It is arranged in such a way that it blocks 0.

In a light beam scanning device having such a configuration, a light beam LB irradiated from a light source (not shown) and deflected every deflection according to the rotation of the rotating polygonal scanning mirror 1 is focused by a focusing lens 2. After that, to the prism type optical element 6,
The light enters from the incident surface 60, is reflected by the reflective surface 61 and is bent, and then emerges from the exit surface 62.
The light is emitted through the photoreceptor drum 5 and irradiated onto the /311 constant scanning line on the photoreceptor drum 5. Here, the prism-type optical element 6 includes: a light beam L at the reflecting surface 61 as described above;
and the exit window 40 of its exit surface 62.
However, the prism type optical element 6 can independently perform the separate functions performed by the reflecting mirror 3 and the dustproof member 4 in the conventional device. Therefore, it is possible to reduce the number of optical components and the effort required for adjustment. Further, FIG. 3 shows a side view of the configuration near the position of the prism type optical element 6 in a light beam scanning device according to another embodiment of the present invention.

As shown in FIG. 3, regarding the reflective surface 61 of the prism type optical element 6, in addition to the embodiments described above, a reflective layer 610 may be formed on the reflective surface 61 by vapor deposition or the like. Further, total reflection may be used for the Fi or the integrated reflection 61. [Effects of the Invention] As explained above, according to the light beam scanning device of the present invention, a single prism type The optical elements are configured and arranged to have the functions of a reflective mirror and a dust-proof member, making it possible to reduce the number of optical parts.This has the advantage of contributing to lower equipment costs and easier adjustment and maintenance. It has a great effect.

[Brief explanation of drawings]

FIG. 1 is a linear plane configuration diagram showing an embodiment of a conventional light beam scanning device, FIG. 2 is a side configuration diagram of a light beam scanning device showing an embodiment of the present invention, and FIG. 3 is a diagram of the present invention. FIG. 6 is a side view showing a configuration of the vicinity of a prismatic optical element arrangement according to another embodiment of the invention. 1... Rotating polygonal scanning mirror, 2... Focusing lens, 5...
・Photosensitive drum, 6... Prism type optical element, 60・
...Incidence surface, 61...Reflection surface, 62...Emission surface, 6
10...Reflection layer, LB...Light beam.

Claims (1)

[Claims] A prismatic single element is disposed on the dustproof window, and the single optical body reflects a light beam that is deflected in a fixed direction and is focused to form an image on the photoreceptor. 1. A light beam scanning device M, characterized in that it has both the function of a reflecting mirror that guides the beam onto a scanning line, and the dust-proofing function of an optical system including the deflection and focusing means.