JPS6332515A - Device which combined concave mirror and convex mirror, for shortening distance required for deflection of laser beam - Google Patents

Abstract

PURPOSE:To shorten a distance required for deflecting a laser beam, by overlapping the focuses of a convex parabolic mirror having a small window in the center and a concave parabolic mirror. CONSTITUTION:A convex parabolic mirror 1 and a concave parabolic mirror 2 are similar to each other, and the mirror 2 is (k) times of the mirror 1 in a similarity ratio. The mirror 1 and the mirror 2 have a small window centering around the optical axis, and its diameter is 1/k of the mirror 1. A vibrating mirror 3 is placed so as to reflect a laser beam by an origin. A laser beam 5 from a laser oscillator is reflected by the mirror 2 and becomes a light beam 6, passes through the small window of the mirror 1 and made incident on the mirror 3, reflected by the focus and becomes a light beam 7, reflected by the mirror 2 and becomes a light beam 8 being parallel to the axis X. Subsequently, the light beam 8 is reflected by the mirror 1 and becomes a light beam 9, reflected by the mirror 2 and becomes a light beam 10 being parallel to the axis X, and made incident on a screen 4. Said light beam can be made incident on an arbitrary point on the screen 4 by adjusting an inclination of the mirror 3. According to this method, a deflection distance can be shortened to about 1/k.

Description

DETAILED DESCRIPTION OF THE INVENTION The laser beam deflection device used in current laser displays is a method of applying a laser beam to a mirror and changing the inclination of the mirror to vibrate it, thereby changing the path of the reflected laser beam ( Figure 1).

Therefore, in order to obtain a large screen, it was necessary to increase the deflection angle of the chain or to increase the distance from 'xt to the screen (hereinafter referred to as deflection distance).

However, it is difficult to increase the deflection angle of a chain that vibrates at high speed, so in reality the only option is to increase the deflection distance.

Therefore, there was a problem in that the depth of the device became large. According to the method described below, this problem can be solved.

FIG. 2 of the specification is a perspective view of an example in which this method is applied to a laser display. And Figure 3 shows the X in Figure 2.

This is a cross-sectional view on the Z plane, and the following description will be made using FIG. 1 and FIG.

First, a brief explanation of Figure 3. ■ is a convex parabolic chain with a small window in the center.

■ is a concave parabolic mirror with a small window in the center.

■ is vibration j! (or rotational tIA) ① Screen ② ② ② ② [Co., Ltd.] Explains the features of the laser beam method by describing how this device works.

The paraboloids of ■ and ■ are similar, and the similarity ratio of ■ is twice that of ■.6■, ■ has a small window (Note 1) centered on the optical axis, and its diameter is the diameter of ■. It is in l/ of. Also, ■,■
have the X-axis as the optical axis, and both have the origin as the focal point. ■ is placed so that the laser beam is reflected at the origin. The laser beam ■ led from the laser oscillator is reflected by ■, becomes D, passes through the small window of ■, enters ■, and is reflected at the focal point ■
becomes. ■ is reflected by ■ and becomes ■, but due to the property of the paraboloid that the light coming from the focal point is changed into a ray parallel to the optical axis, ■ is linear parallel to the X axis, and ■ corresponds to ■. (Note that the extension of ■ passes through the focal point, t) becomes 0 parallel to the X axis and enters the screen. By adjusting the slope of (2), it is possible to make the light incident on any point on the screen.

According to this method, the deflection distance can be shortened to about 1/k of that of the conventional method, and the laser beam can be made perpendicular to the screen without depending on the inclination of (2).

In addition, the paraboloid in this example can be called a hyperboloid or an ellipsoid (Note 2).
The same thing can be done by replacing .

In this case, by arranging a spherical screen centered at F2, the laser beams can be made to enter the screen at right angles. This is shown in @4, Figure 5.

In addition, the parabolic mirror used in the first example has a surface of X=a (Z'+Y') (a is a constant), but in some cases, X=aZ"
It is also conceivable to configure the device with a mirror surface having no curve in the Y-axis direction, such as a surface +OY. This means that
This also applies when replacing a paraboloid with a hyperboloid or ellipsoid.

When the slope of specification note 1.0 is small, it is necessary to prevent the laser beam a@l from entering the parabolic mirror (■) instead of the screen.

Note 2. Hyperboloids and ellipsoids have two focal points, but a hyperboloid has the property of reflecting light from one focal point away from the other focal point, and an ellipsoid has the property of reflecting light from one focal point away from the other focal point. It has the property of reflecting the light that comes to it towards the other focal point.

[Brief explanation of the drawing]

Figure 1 shows a conventional deflection method.■ is a vibrating mirror (or one-turn mirror). ■ is a screen. ■ and ■ are laser beams. FIG. 2 is a perspective view of an example of the present invention in use. (2) is a convex parabolic mirror with a small window in the center. ■ is a concave parabolic mirror with a small window in the center. ■ is a vibrating mirror, (or rotating ia) ■ is a screen. Fig. 3 is a cross-sectional view of Fig. 2. ■ is a convex paraboloid with a small window in the center. Specification ■ is a concave paraboloid with a small window in the center. ■ is a vibrating mirror (or rotation j1 and ■ is a screen. ■, ■, ■, ■, ■, @ is a laser beam. Figure 4 is a diagram in which the paraboloid in Figure 3 is replaced with a hyperboloid. ■ is a convex hyperboloid chain. It has a small window in the center. ■ is a concave hyperboloid mirror with a small window in the center. ■ is a spherical screen at the center F2. Fl and F2 are the focal points of the hyperboloid. Figure 5 shows the paraboloid in Figure 3 as an ellipsoid. The figure replaced with ■ is a convex ellipsoidal mirror with a small window in the center. ■ is a concave ellipsoidal mirror with a small window in the center. ■ is a spherical screen at the center F2. Fl and F2 are the focal points of the ellipsoid.

Claims (1)

[Claims] A device that shortens the distance required to deflect a laser beam by using two quadratic curved mirrors with overlapping focal points.