SU1585622A1 - Device for illuminating a narrow strip of subject plane of optical system - Google Patents

Abstract

The invention may be used in one-dimensional image scanning devices, such as reprographic apparatus or optical reading machines. The purpose of the invention is to increase the efficiency of using the light flux of the light source. A device for illuminating a narrow strip on the object plane of the optical system contains a main mirror reflector 1, made in the form of a segment of an elliptical cylinder with flat ends, a light source 2 and two additional mirror reflectors 5 and 6, the first of which is made in the form of an elliptical cylinder segment, and the second - in the form of a flat reflector or in the form of an elliptical cylinder. Part of the luminous flux of the light source 2 is assembled by the main reflector 1 on the subject plane 7 of the optical system 8. The remaining portion of the flux is focused on the subject plane 7 by jointly working additional reflectors 5 and 6. This makes it useful to redistribute almost the entire luminous flux of the light source 2 to the subject plane 7. 3 C.p. f-ly, 3 ill.

Description

6 g

The invention relates to illuminators and can be used primarily in one-dimensional image scanning devices, for example, in reprographic apparatus or optical reading machines.

The purpose of the invention is to increase the efficiency of using the light flux of a light source by concentrating the radiation on the object plane of the optical system within a narrow band of a given length.

Figures 1 and 2 schematically show a device for illuminating a narrow strip on the object plane of the optical system in two planes, exemplary embodiments; on fig.Z - view A in figure 1 and 2.

A device for illuminating a narrow band in the object plane of the optical system of FIG. 1 and 2 includes a main reflector 1, whose mirror surface is made in the form of an elliptical cylinder segment, a light source 2 located on the first focal line F1,1 of the main reflector 1, the first 3 and the second 4 flat reflectors (ends), the first additional reflector 5, the mirror surface of which is made in the form of a segment of an elliptical cylinder with a longitudinal slit, and a second additional reflector 6 transferring the luminous flux reflected by the first additional reflector 5 to the second focal line of the core New reflector 1. The latter can be made in the form of a flat reflector (figure 1) or in the form of a segment of an elliptical cylinder (figure 2). The first focal line F1,1 of the main reflector 1 coincides with the first focal line F1,2 of the first additional reflector 5, the second focal line F 2,1 of the main reflector 1 coincides with the intersection line of the subject plane 7 and the sagittal plane of the optical system 8, hereinafter referred to as the longitudinal axis the slits, and the first 3 and second. 4 flat reflectors are made overlying the area of the projections of the rays in the device onto the plane perpendicular to the subject plane 7.

The device of figure 2 may contain an additional source of light 9.

The device of figure 1 works as follows.

When the light source 2 is switched on, a part of the light flux falls on the mirror surface of the reflector T and is focused on its second focal line F 2,1 lying in the subject plane 7.

Another part of the luminous flux from the source 2 of light falls on the mirror surface of the reflector 5, which forms a luminous flux converging on its second focal line F 2,2. A flat reflector 6 located at an angle to the plane passing through the first F 1.2 and second F 2.2 focal lines of the reflector 5 so that the image F 2.2 of the second focal line F 2.2 coincides with the second focal line F 2.1 Reflector 1, transfers this converging beam to the second focal line F 2.1 Reflector 1.

Since the width of the longitudinal slit of the reflector 5 is small due to the fact that the axis of the longitudinal slit coincides with the focal 5 line F 2,1, the device provides an angle of coverage of the source 2 of light in the meridional plane, close to In rad. Therefore, a portion of the light flux incident on the mirror surfaces of the reflectors 3 and 4, 0 is also focused on the second focal line F 2.1.

As a result, a narrow band is formed on the object plane 7 of the optical system 8, the width of which is determined by the transverse size of the source 2 of the light. Since the flat reflectors 3 and 4 are made to overlap the area of the projections of the rays in the device onto a plane perpendicular to the object plane, the length of the illuminated narrow band is determined by the distance between them.

The device according to figure 2 works as follows.

When the light source 2 is turned on, part 5 of the light flux falls on the mirror surface of the reflector 1 and is focused on its second focal line F 2,1 lying in the subject plane 7.

Another part of the light flux from the source 2 of light falls on the mirror surface of the reflector 5 and is focused on its second focal line F 2.2, which coincides with the first focal line F 1.3 of the reflector 6. Then this part of the light flux 5 falls on the specular the surface of the reflector 6 and is focused on its second focal line F 2,3 lying in the subject plane 7.

In case the device is equipped with an additional source 9 of light located on the first focal line F 1.3 of the reflector 6, when it is switched on, part of the light flux from the source 9 of the light falls on the mirror surface of the reflector 6 and focuses on its second focal line F 2, 3 lying in the subject plane 7. Another part of the light flux from the source 9 of light falls on the mirror surface of the reflector 5 and focuses on its j-fial F 1.2 line, which coincides with Foi;

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fie.Z

Claims (4)

Claim 1. Device for illuminating a narrow strip on the subject plane of the optical system, comprising a main mirror reflector made in the form of a segment of an elliptical cylinder with two flat ends mounted perpendicular to the latter, and a light source located on the first focal line of the cylindrical part of the main mirror reflector, characterized the fact that, in order to increase the efficiency of use of the light flux of the light source, it is equipped with two additional mirror reflectors, the first of which is made in the form of a segment of an elliptical cylinder with a longitudinal slit and installed so that its first focal line is aligned with the first focal line of the main specular reflector, and the longitudinal axis of the slit of the first additional reflector is aligned with the second focal line of the main specular reflector a mirror reflector is placed on the side of the mirror surface of the first additional reflector and is designed to transfer the reflected additional first mirror reflector of the light source of the light source onto a narrow strip of the subject plane. 2. The device according to claim 1, characterized in that the second additional mirror reflector is made in the form of a segment of an elliptical cylinder and is installed as follows. that its first focal line is aligned with the second focal line of the first additional specular reflector, and the second focal line with the second focal line of the main specular reflector. 3. The device according to claim 1, characterized in that. that the second additional mirror reflector is made flat. and installed so that the image formed by it of the second focal line of the first additional mirror reflector is aligned with the second focal line of the main mirror reflector. 4. The device according to claims 1-3. characterized in that the flat ends of the main mirror reflector are made of such dimensions that in the working state they overlap the projection area of the light rays on the plane of installation of the ends. G2.2 in id A F2.1 FZ3 ---·-.......... 1........-...... ........- .......... t ---------------- _s • • A/. 2; F1.3 ', F2.2 g Fig.Z