JPH0219780Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an optical scanning device that uses laser light and is used in optical printers, facsimiles, display devices, and the like.

Conventionally, as this type of optical scanning device, a mechanical optical scanner using a galvanometer mirror or a rotating polygon mirror, a non-mechanical optical scanner using an acousto-optic or an electro-optic crystal, etc. are known. Among these, rotating polygon mirrors rotate at high speed, have a large deflection angle, and can obtain high resolution, so they are widely used in laser marking devices such as printers, printing plate making, laser displays, and surface inspection equipment. .

FIG. 1 is a sectional view of a main part showing an example of a conventional optical scanning device using a rotating polyhedron. The rotation of the motor 1 is transmitted to the spindle 3 via the coupling ring 2, which rotates the rotating polygon mirror 4, which is installed on the collar 31 of the spindle 3 and is held down by the holding plate 5 (in this case, a nut). The reflective surface 41
Deflects a light beam incident on the. In this case,
The deflection that occurs at point A of the flange portion 31 of the spindle 3 during rotation is directly expressed as a variation in the inclination angle α of the reflective surface 41 of the rotating polygon mirror 4, and the resulting scanning line is located in a direction perpendicular to the scanning direction. This may cause misalignment or uneven pitch. In order to prevent this, conventional devices have had the problem of requiring high machining accuracy, such as grinding the flange portion 31 to suppress the runout at point A to within 0.6μ.

This invention was devised to solve the above problems, and has realized an optical scanning device using a rotating polygon mirror that can reduce fluctuations in the angle of inclination of the reflecting surface without requiring high precision during manufacturing. It is intended to.

According to the present invention, a rotating polygon mirror is sandwiched between the collar of the spindle and a holding plate, and the rotating polygon mirror is rotated by displacing the collar in a direction perpendicular to the plate surface using an adjustment screw provided on the plate surface of the holding plate. The above objective can be achieved by adjusting the angle of inclination of the reflective surface of the polygon mirror.

The present invention will be explained below based on the drawings.

FIG. 2 is a cross-sectional view of essential parts of an embodiment of the optical scanning device according to the present invention, in which a rotating polygon mirror 4 and a spacer 7 are provided between the collar 31 of the spindle 3 and the holding plate 51 (in this case, a nut). The holding plate 51 is provided with the same number of adjustment screws as the rotating polygon mirrors. When the adjusting screw 81 is tightened, the tip of the adjusting screw 81 pushes the spacer 7, rotating polygon mirror 4, and flange 31 together, causing displacement in a direction parallel to the axis of the adjusting screw 81. Since the flange portion 31 displaces (bends) more toward the outside from the central axis of the spindle 3, the angle of inclination of the reflective surface 41 of the rotating polygon mirror 4 also displaces accordingly. In this way, by turning the adjustment screw, it is possible to correct the error that occurs in the angle of inclination of the reflective surface 41 due to the bending of the surface of the flange portion 31. The amount of adjustment at this time can be read using the dial gauge 9.

FIG. 3 is a cross-sectional view of a main part showing another embodiment of the optical scanning device according to the present invention, in which the rotating polygon mirror 4 is pressed against the collar 31 of the spindle 3 by a pressing plate 52 having a cavity 10. The holding plate 52 and the center axis of the spindle 3 are connected to each other by adjusting screws in the same number as the number of surfaces of the rotating polygon mirror. When the adjustment screw is tightened, the peripheral part of the lower surface of the holding plate 52 presses the rotating polygon mirror 4 and the flange 31, so by turning the adjustment screw as in the first embodiment, the surface of the flange 31 is bent. Errors occurring in the angle of inclination of the reflective surface 41 can be corrected.

With the configuration shown in the above embodiment, the bending of the spindle collar surface can be corrected by adjusting the adjustment screw, which reduces the requirements for spindle machining accuracy and improves machining. It becomes easier. Further, by using a plurality of adjustment screws, it is possible to correct the twist of the rotating polygon mirror for each reflecting surface.
Furthermore, since it is possible to realize an optical scanning device with a strong structure, no vibration occurs during rotation, and stable optical scanning is possible. Furthermore, the structure is simple and can be realized by combining parts with a simple structure, making it easy to manufacture.

As described above, according to the present invention, it is possible to realize an optical scanning device using a rotating polygon mirror with a simple configuration, which can reduce fluctuations in the angle of inclination of the reflecting surface without requiring high precision during manufacturing. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an example of a conventional optical scanning device, FIG. 2 is a sectional view of a main part showing an embodiment of an optical scanning device according to the present invention, and FIG. 3 is a sectional view of a main part showing an example of a conventional optical scanning device. FIG. 3 is a sectional view of a main part showing an example. 3...Spindle, 31...Spindle collar, 4...Rotating polygon mirror, 41...Reflecting surface, 51,
52... Holder plate, 81, 82... Adjustment screw, α
...Inclination angle.

Claims (1)

[Scope of utility model registration request] In an optical scanning device using a rotating polygon mirror as a means for scanning light, there is provided a spindle having a flange, a holding plate attached to the spindle and sandwiching the rotating polygon mirror between the flange, and the rotating polygon mirror. and a plurality of adjustment screws provided on the plate surface of the holding plate corresponding to each reflective surface of 1. An optical scanning device characterized in that the angle of inclination of each reflecting surface of a rotating polygon mirror is adjusted by bending it in a certain direction.