JPS61188516A - Rotating polygon mirror - Google Patents

Abstract

PURPOSE:To prevent easily the dividing angle error of respective reflecting surfaces and to improve the quality with a low-priced constitution by providing a groove in a central direction from an edge between respective reflecting surfaces of the rotating polygon mirror. CONSTITUTION:The groove is formed in the central direction from the edge between respective reflecting surfaces 3 of a rotating polygon mirror main body 2, the groove is easily further opened at the core-shaped part 5 of the inner edge part of the groove, the crack is prevented to occur and a taper- shaped female screw 6 is formed at the external edge part. A taper screw 7 is screwed into the screw 6, the width of the groove is further opened, the angle of respective reflecting surfaces 3 is changed, the dividing angle error of respective reflecting surfaces can be easily corrected by adjusting the screw 7, and without the processing accuracy, a polygon mirror 1 having the high quality can be manufactured, the electrical dividing angle correction as well is not needed, and the device can be obtd. with low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rotating polygon mirror used in laser beam printers, facsimile machines, etc., which scan laser beams to read or record images.

2. Description of the Related Art Recently, single-rotation polygon mirrors have been widely used in fields such as laser beam printers, laser scanners, and facsimile machines used as computer output terminals.

A conventional rotating polygon mirror will be explained based on FIG.

The '-0 rotation rotating mirror 101u is formed into a polygonal shape.The outer surface in the circumferential direction is formed as a reflective surface 1o2.

By irradiating the entire reflective surface 102 of the rotating polygonal mirror 161 with the laser beam, scanning with the laser beam can be performed. Since such a rotating polygon mirror 1o1 has a great influence on the output image quality of a laser printer or the like, it needs to have a very highly precise shape, and is manufactured by precision diamond machining of aluminum.

Problems to be Solved by the Invention However, it is extremely difficult to obtain the necessary precision by using such diamond processing, and production errors occur. Among the manufacturing errors of the rotating polygon mirror 101, each reflecting surface 1
The division angle error of o2 causes a scanning position error of the laser beam and deteriorates the output image quality of a laser printer or the like.

A method of correcting this error using electrical means has also been considered, but this method has the drawback of making the device expensive.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a rotating polygon mirror that can prevent errors in the dividing angles of each reflecting surface and that can achieve high quality at low cost.

Means for solving the problems and the technical means of the present invention for solving the above problems are as follows: a rotating polygon mirror body; It is provided with grooves formed therein and means for expanding these grooves.

Effect Since the present invention has the above configuration, the angle of the reflective surface divided between each groove can be accurately adjusted by widening the groove dividing each reflective surface as necessary. This makes it possible to correct the division angle error of each reflective surface.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a partially cutaway front view, in which the rotating polygon mirror body 2 of this embodiment is formed of aluminum into a polygonal shape (hexagonal in the illustrated example), and the outer surface in the circumferential direction is formed by precision diamond machining. It is formed on the reflective surface 3. Grooves 4 are formed so as to divide each reflective surface 3 toward the center from the ridge between each reflective surface 3. The inner end of the valley groove 4 is formed into an arcuate portion 6 to facilitate expansion of the groove 4 and to prevent cracks from forming. The outer end of the valley groove 4 is formed into a tapered shape that gradually widens toward the outer end, and a female thread 6 is formed on the inner surface thereof. A tapered screw 7 is screwed into each female screw 6 as a means for widening the groove 4.

Next, the operation of the above embodiment will be explained. The width of the groove 4 can be expanded by advancing each tapered screw 7, and since each reflective surface 3 is divided by the groove 4, the angle of each reflective surface 3 can be changed. Therefore, the error in the dividing angle of each reflecting surface 30 can be corrected by adjusting each taper screw 7, and accurate dividing angles can be obtained.

Effects of the Invention As is clear from the above explanation, according to the present invention, grooves are formed from the ridges between the respective reflecting surfaces of the rotating polygon mirror body toward the center, and a means for widening these grooves is provided. Since the i-turn polygon mirror can be easily corrected for each reflective surface division angle error, high-precision machining is not required in its manufacture, and a high-quality i-turn polygon mirror can be obtained at a low manufacturing cost.

Furthermore, since the dividing angle of each reflective surface is accurate, the output image of a laser printer or the like will be of high quality, and there will be no need to electrically correct the dividing angle, making it possible to realize an inexpensive device.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the rotating polygon mirror of the present invention, and FIG. 2 is a perspective view of a conventional rotating polygon mirror. 1...Rotating polygon mirror, 2...Rotating polygon mirror body, 3, □...Reflecting surface, 4...Groove, 7
...Taper screw. Name of agent: Patent attorney Toshio Nakao and 1 other person3-
Reflection fan 4-Ichisei WE2 figure

Claims (1)

[Claims] A rotating polygon mirror comprising a rotating polygon mirror body, grooves formed toward the center from the ridges between the reflecting surfaces of the rotating polygon body, and means for expanding these grooves. .