SU59045A1 - Ion detection lamp - Google Patents

Description

Currently, a whole series of schematic diagrams of three-color colorimeters are known, intended for measuring color by mixing three color beams in various proportions and visual color balance in the visual field. All of these devices belong to the discharge of additive colorimeters and differ from each other in ways of mixing color beams. The well-known device L. I. Demkina uses a mixture of beams that pass through different parts of the same lens, which are covered by three color filters. The resulting beams form a single image, in which the colors are mixed.

The device basically suits its purpose, however it is very cumbersome. The colorimeter Hilda uses the principle of mixing beams, you get them, they are not simultaneously in the eye, but so quickly one after the other, that the eye perceives one continuous impression. The so-called Maxwell turntables use the same principle of very fast flicker. There are a number of principles that can be put into. basis of additive color mixing.

Some advantages over the principles mentioned above can be given by the method of blending beams, according to which three colored light beams (for example, red, green and blue) converge on one white diffuse scattering platform at right angles to each other and form a crosshair, similar to three axes of a rectangular coordinate system at the beginning of which an illuminated platform is placed. If the pad, turning, changes its position with respect to the direction of the incident beams, then the ratio of the illuminances generated by the three beams will change according to the change in the cosines of the angles of incidence of the beams. Each of the beams creates maximum illumination if it falls perpendicularly to the surface of the site. In this position, the illuminations generated by each of the two other beams will be zero, respectively, the cosines of their angles of incidence. In the middle position, when the angles of incidence of all three beams will be equal to each other, the beams will be mixed in equal proportions. By turning the pad you can always choose any ratio for three

mixed beams. If, as the sighting direction, we select just the mentioned mean direction, which is equal angles with all three beams, then at all the turns the platform will be clearly visible to the observer.

 The proposed colorimeter is based on this last principle, and in it, as in other well-known colorimeters, a spherical surface is used to mix colors.

According to the invention, three beams of colored rays are directed into a hatch at the base of a hemisphere, covered from the inside with a layer of white diffusing paint, in three mutually perpendicular directions, and the hemisphere itself is pivoted about two axes in order to smoothly change the color of its integrating surface.

Such a device of a colorimeter makes it possible to free from defects of the above scheme with three mutually perpendicular rays converging on one diffusely scattering platform, associated with deviations in the emission of this latter from Lambert's law.

In FIG. Figure 1 shows a section of a hemisphere with a plane passing through two of the three intersecting rays; FIG. 2 is a schematic section of the proposed colorimeter (vertical plane) through the ocular p and the LyumvragBrogun cube; FIG. 3 is a plan view of a colorimeter.

As can be seen from FIG. 1, each of the beams of colored rays penetrates into the hemisphere in an amount proportional to the cosine of the angle of fall. Inside these hemispheres, after repeated reflections, they mix and form a mixture with an appropriate color at the sited wall C of the wall. The third beam falling on a hole perpendicular to the k-plane of the drawing will also go inside the hemisphere in proportion to the cosine of its angle of incidence. It should be expected that the chromaticity of the site of the hemisphere wall will correspond to the color that would have an ideally dissipative 1a surface that occupies the position of the aperture. .

An observer who looks through the eye of O (Fig. 2) will see the Lummer cube L, and the color of one floor will be determined by pattern A, which is located on the continuation of the axis of the ocular, and the color of the other will depend on the rotation of the hemisphere R. Lamp S sends to the opening of the hemisphere P three beams of light that pass through the light filters and are reflected from the mirrors, one of which is Zi seen in fig. 2 behind the cube L. The other two mirrors Z and Z. are on the other side of the cut plane (Fig. 3) and therefore in Figs. 2 are not visible. The scale B-B of the device, applied on a transparent glass, is visible above the hemisphere R. The reference pointer specifies the direction of the normal to the base of the hemisphere.

Test sample A is illuminated by the same S-lamp, the glow of which must be chosen so that its color temperature is 2848 ° K (internationally accepted source A). Mirror Z serves to illuminate the sample.

Since simultaneously with the change in the color of the opening of the hemisphere P, its brightness also changes during turns, it is necessary to place a device between lamp S and test sample A to change its illumination. Such a device, which will allow equalizing the luminance of the two parts of the field of view, can be carried out in the form of a neutral photometric wedge K (Fig. 2).

The author points out that the advantage of the described device is that its comparison field — the hemisphere P mounted on the ball joint, has two degrees of freedom, which allows the field to change color in an arbitrary direction.

Changing the readings on separate scales, the observer changes the color of the comparison field in one of two or three predetermined directions, but not in any direction. In addition, the proposed device allows a direct reading of the result on a two-dimensional scale, on which a grid is drawn in coordinate axes by means of preliminary calibration.

The device can be sufficiently compact and, since it uses only one lamp, it should be of little sensitivity to insignificant changes in mains voltage.

The subject matter of the invention.

A three-color colorimeter using an integrating hemisphere illuminated by three beams of colored rays, characterized in that the latter are aimed at the hatch of the hemisphere in three mutually perpendicular directions, and the hemisphere itself is rotatable about two axes in order to smoothly change the color of its integrating surface ..V

C .fig 1