JPS58184901A - Rotary mirror - Google Patents

Abstract

PURPOSE:To obtain an inexpensive optical scanner by machining a specular surface to form machining streaks in parallel or inclination to an optical scanning line so that beams of zero order and diffracted beams of higher order do not scan superposedly on the optical scanning line. CONSTITUTION:A reflection surface 2 is so machined that the machining streaks 2' thereof intersect orthogonally with a revolving shaft 8 so that the array of diffracted beams 6' and 7' of higher order intersect orthogonally with a scanning line 4. The line 4 of a scanning beam 5 and the beams 6', 7' scan in parallel apart at a certain space between each other but do not scan superposedly. A shielding plate is provided if the superposed harmful scanning arises by having a time lag on the scanning line of the beam 5 owing to the presence of the diffracted beams of higher order. The plate 9 is provided with an aperture of a fine slit 10 for allowing the passage of only the main scanning beam 5 to shut off the diffracted beams of higher order. The machining streaks are thus allowed to a certain extent and the stage of manufacture is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides ill! The present invention relates to a rotating mirror suitable for use in particular with optical scanning.

The object of the present invention is to cut the genus w&- and to cut the
This eliminates the troublesome work process in producing mulberry and provides a low-cost method of rotation.

In 111-surface finishing processing by cutting, it is extremely difficult to completely remove cutting marks. However, even if there is a slight amount of diffracted light due to cutting marks, it is not harmful unless the diffracted light is superimposed on the zero-order light within one travel distance, except for a slight decrease in reflection efficiency. Therefore, in order to reduce costs, some cuts have been made to P8II.
Even if the stripes remain, the high-order diffraction light can be blocked by a light-transmitting plate, making an inexpensive optical scanner a turning part.

Hereinafter, the present invention will be explained using FIAIIi.

Figure 1 shows the case of rotation -9 in which the cutting needle is parallel to the rotating mirror 8 and perpendicular to the scanning line, and is an explanatory diagram of a stone example without generating harmful higher-order diffracted light.

The outer periphery of Ichisen-1 is multi-faceted with a one-sided cutting finish.
One surface 2 has cutting marks 2' parallel to the rotation axis 8. This rotating mirror 1 is rotated about a rotating shaft 8, and the incident light 3 is reflected onto the reflecting surface 2.
The light is incident on the scan @ 4 according to the rotation of the polygon mirror. In this case, light is diffracted by the cutting streaks 2' on the reflective surface 2, and high-order diffracted light 6. and 7 occur. When the cutting streak 2 is perpendicular to the optical scanning #I4, the higher order folded beams 6 and 7 are scanned! ! - matches,
There are drawbacks to using the scanning light beam 5 and superimposed scanning.

The non-inventive work is the overlap of cutting marks by higher-order diffracted light'yI:
In order to eliminate the drawback of f, the direction of the cutting streaks is limited and 9 will be explained using a rotating mirror shown in Fig. m2.

The reflective surface 2 and the cut U-stripes 2' are cut so as to be perpendicular to the rotation axis 8, and the array of the 11th higher-order diffraction lights 6' and 7' scans! I made it perpendicular to 4. Therefore, the scanning line number of the scanning light 5 and the diffracted light e1. tl performs parallel scanning with stations between stations, but does not perform overlapping scanning.

However, if harmful scanning occurs due to the four divisions of higher-order diffracted light overlapping on the scanning line of the scanning light 5 with a time difference of t, as shown in FIG. It is a good idea to provide a board. In FIG. 3, the light shielding plate 9 has an Om original 1G (Z) opening for passing only the main scanning light 50, and blocks higher-order diffracted light.

When the cutting streaks are made parallel to the scanning line, the higher-order diffracted light is orthogonal to the scanning l1AVc, and the diffracted light is most likely to be blocked. 1 fermentation or curve 4') may be used for the striations.

The direction of the striations is not necessarily the rate! It must be parallel to the edge! It may be inclined instead, but the degree of this inclination is determined by the pitch gap between the cutting marks.

FIG. 4 is an explanatory diagram of scanning beam overlap, and the scanning beam diameter and
Although #4 of the diffracted light differs depending on the cutting pitch, if the streak is inclined by an angle lL#, the amount of dispersion in the direction perpendicular to the scanning line needs to be larger than the diameter of the scanning beam 5.

According to the present invention, there is no need to completely eliminate the cutting defect PA9kK, and the cutting length can be reduced by approximately 1 g. Therefore, - the manufacturing process can be simplified,
It is possible to reduce costs. 1

[Brief explanation of drawings]

Figure g1 is a diagram explaining optical scanning using a cut polygon mirror, Figure 2 is a diagram showing an embodiment of the present invention, Figure #G3 is a diagram showing another example of the present invention, and Figure 4 is a diagram explaining optical scanning. Here's a diagram to explain. ￥J 1 Figure 2 Figure ゛v6 J Figure

Claims (1)

[Claims] 1. In an optical scanning machine consisting of a cutting St+- surface reflection plane and a vibrating shelf or rotating shaft, the mirror cutting streaks are parallel or inclined to the optical scanning layer, and the zero-order light and higher-order diffracted light are transmitted on the optical scanning Tt-. A rotating mirror that makes the superimposed set meal t4$.