SU1413576A1 - Optical system of projection device - Google Patents

Abstract

The invention relates to an optical instrument, in particular, to a projection technique, and makes it possible to increase the illumination of the screen while maintaining equal illumination at the opposite edges of the screen. The optical system of the projection device contains a spherical reflector 7, the center of curvature of which is aligned with the center of a constant voltage arc lamp with a thickened positive electrode 5 and a negative electrode 6 and t with the first focus 8 of the ellipsoidal reflector 9. The image of the source from the first focus 8 is transferred to the second focus 12 reflector 9, which is optically coupled to the center 10 of the input

Description

with SP

O5

Phage / pupil 11 lens 1. Optical axis

13 lens 1 passes through the center

14 of the screen 3, the first focus 8, the second focus 12 and within the range of 2 degrees of the coverage of the capacitor 4 does not coincide with the optical axis 15 of the spherical reflector

7 by the angle determined depending on the characteristics of the lamp and the spherical reflector. The constant voltage arc lamp has an uneven indicatrix dissipated in the vertical plane, as a result of which, within the angle o, will go less

energy than within its equal angle of 0/2. The ellipsoidal reflector 9 changes the ratio of these energies in such a way that less energy goes to capacitor 4 within a smaller angle, and more energy goes to condenser 4 within a larger angle. The alignment of illumination at points A and B of screen 3 is provided by calculating the angle p, according to the dependencies given in the claims. 2 Il.

one

The invention relates to optical instrumentation and can be used in the development of projectors,

The aim of the invention is to increase the illumination of the screen while maintaining a uniform illumination at the opposite edges of the screen.

FIG. 1 shows a diagram of an optical system with a lens condenser; in fig. 2 - the same, with a mirror; condenser.

The optical system contains a lens 1 (FIG. 1), a personnel window 2, a screen 3 and an illuminator including a capacitor 4, an arc lamp with a thickened positive electrode 5 and a thin negative electrode 6 and a spherical reflector 7, the center of curvature of which is aligned with center of the lamp (middle of the interelectrode distance) and the first focus 8 of the ellipsoidal reflector 9. The center 10 of the entrance pupil 11 of the lens 11 is optically coupled to the second focus 12 of the reflector 9. The optical axis 13 of the lens 1 passes through the center 14 of the screen 3, the first focus 8 , second focus 1 2 and within an angle of 2 P | the coverage of the capacitor 4 does not coincide with the optical axis 15 of the spherical reflector 7 by the angle p. Angle / 5 does not depend on the characteristics of the lens and the condenser, which transmits beam of rays, symmetrical to the optical axis 13, but depends only on the characteristics of the lamp and the spherical reflector and is determined by the following relationship;

m

Pk is half the angle of coverage of the cook. Sensor;

mi i ko

,

m

total uniform radiation of the lamp;

-the uniform radiation of the lamp in the direction of the ellipsoidal reflector (the ratio of the luminous intensity measured on the indicatrix of the radiation of the lamp in the direction of the opposite edges of the screen;

-efficiency coefficient of a spherical reflector (the ratio of the forces of light in the direction of the optical axis of the reflector FROM the lamp to the ellipsoidal reflector without a spherical reflector

and with reflector).

Fig. 2 shows the optical layout of the projection device, in which the ellipsoidal reflector 9 simultaneously performs the role of a mirror condenser. In a variant of the scheme, a flat mirror 16 can be used for compactness of the device. In this case, the center 10 of the entrance pupil 11 of the lens 1 is aligned with the mirror reflection 12 of the second focus 12 of the ellipsoidal reflector 9.

The optical system of the projection device operates as follows.

3,

Claims (1)

Due to the spherical reflector 7 and the ellipsoid reflector 9, the image of the source formed between the electrodes 5 and 6 in the form of a ball of light, which is conventionally taken over a point source, is transferred to the second focus 12 of the ellipsoidal reflector 9, the Xenon lamp has an uneven display radiation in the vertical plane, as the thick electrode shields some of the energy. Thus, from the radiation source within the angle c /, there will be less energy than within the same angle d. An ellipsoidal reflector 9 installed in the path of the rays changes the ratio of these energies; less energy, coming out within the limits of the angle o, comes to the condenser within the smaller angle i / (j / 3 t and greater energy, coming out within the limits of the angle t (comes to the condenser within the larger angle. Depending on the angle / 3, the density The energy at the extreme points of the input surface of the condenser 4 changes in the direction of convergence of their values. Condenser 4 and lens 1, whose optical axes are aligned, do not change the ratio of these energy densities (illuminances). The alignment of illumination at points A and B is provided by calculating the angle p depending and the uniformity of the radiation lamp within a selected angle coverage and effectiveness of the reflector. invented Formula and The optical system of the projection device containing „ 3576 installed illuminator, including a spherical reflector, the center of curvature of which is combined with the center of a DC arc lamp, —and a condenser, frame window, lens and screen, which, in order to increase screen illumination while maintaining equitability at opposite edges screen, between the lamp and the condenser, an ellipsoidal reflector is additionally introduced, the first focus of which coincides with the center of the lamp, and the second focus is optically conjugated with the center of the entrance pupil of the lens, while the optical axis is about The lens passes through the center of the screen, the first and second foci of the ellipsoidal reflector do not coincide within the angle of the condenser with O five 0 the axis passing through the center of the spherical reflector, the angle R 1 - D1 1 + m to where half the angle of coverage of the capacitor; thirty m 1 + Kom five where m is the radiation uniformity lamps in the direction of the ellipsoidal reflector (the ratio of the luminous intensity measured on the indicatrix of the lamp radiation in the directions to the opposite edges of the screen); spherical reflector efficiency ratio. TO" 12 Figg