JPS6057050B2 - Luminous flux rotation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a beam rotation device that rotates, for example, a two-split beam from a laser light source or a beam from a plurality of light sources.

This type of beam rotation device crosses two laser beams in a fluid or on the surface of a moving object to be measured, and obtains scattered light based on particles in the fluid or surface roughness of the moving object. It is used in devices that measure the speed, movement state, vibration state, etc. of a measured object by measuring the Doppler frequency.

An example of the basic configuration of a conventional beam rotation device of this type is as shown in FIG.
is split into, for example, 2a' and 2b' by a splitter 3, one of the split beams 2a' passes through a black cell 4, and the other beam 2b' remains as it is, and passes through two rhombic prisms 5, 5 and a converging lens 6 at the measurement point 2c.

Note that 7 indicates the central axis. Therefore, in this type of measurement, if it is necessary to rotate the divided beams together to change the irradiation direction of the beam at the measurement point 2c, force distortion often occurs, but the conventional configuration described above In the light source 1
and all the optical systems A) except the focusing lens 6, i.e. the splitter 3, the black cell 4 and the two prisms 5, 5 together, while maintaining their optical relative positions).
This operation is extremely complicated and requires considerable skill and time to adjust the relative positions of each optical element after rotation, resulting in extremely inefficient operation. It was something.

The present invention aims to provide a light beam rotation device that eliminates the above-mentioned drawbacks.

The present invention will be explained below with reference to FIG. 2 of a typical embodiment.

In the figure, a beam 2 from a laser light source 1 passes through an optical system similar to the conventional type described above, that is, a beam splitter 3, a black cell 4, and rhombic prisms 5, 5, and is split into two. The thus-split beams 2a and 2b intersect at the measurement point 2c by the focusing lens 6 via two opposing cylindrical lenses 8a and 8b which are integrally rotatable.

Incidentally, the lenses Ba and 8b are constructed integrally under predetermined conditions, and have a structure in which they do not move individually. In an embodiment having such a configuration, by rotating both the cylindrical lenses 8a and 8b, that is, the portion indicated by B, on the central axis 7, the cylindrical lenses 8a and 8b are crossed at the measurement point 2c. The irradiation direction of the two beams can be rotated.

This will be further explained in detail with reference to FIG. 3 (perspective view).
In addition, each figure shows the cylindrical lenses 8a and 8b as 445.
The figure shows the state in which the parts are rotated one after another. First, to explain Figure A, this figure shows the case where the respective axes x of the lenses 8a and 8b are set horizontally, and the two beams 2a and 2b entering from the incident side A of the lens 8a are both refracted. The light is emitted from the exit side opening of the lens 8b while maintaining the current state.

Next, explaining figure b, this figure shows the axis X of lenses 8a and 8b.
This figure shows a state in which the beam is rotated by 45 degrees from the state shown in FIG.

To further explain Figure C, this figure shows a state in which the lenses 8a and 8b have been rotated by 90 from the state shown in Figure A.
In this case each beam at the exit side is rotated by 1800 revolutions.

Similarly, Figure d shows a state in which the lenses 8a and 8b are rotated by 135 mm, and in this case, each negative beam at the exit side exit is further rotated by 180 degrees than in the case of Figure B. When the cylindrical lenses 8a and 8b are rotated by θ0 as described above, two beams 2a and 2
b is rotated 200 times relative to that of incident side a.

As described in detail in the embodiments, the present invention integrates two cylindrical lenses 8a and 8b, and by simply rotating them, it is possible to set the measurement point 2c with all other optical systems fixed. The irradiation direction of the two light beams can be rotated, and the operation is extremely simple, and since the optical system for rotation is integrally constructed, its optical accuracy is maintained), and it is not as simple as conventional There is no need to modify the arrangement of optical elements, and from these points of view it is extremely efficient and can provide a reliable beam rotation device, making it an extremely effective invention. .

[Brief explanation of the drawing]

FIG. 1 of the accompanying drawings shows an example of an optical system of a conventional beam rotation device.

Claims (1)

[Claims] 1 Two cylindrical lenses are configured to face each other and rotate integrally in the same direction, and the lenses are arranged on the central axis between the plurality of laser beams and the focusing lens, A light beam rotation device characterized in that the irradiation direction of each of the light beams at a measurement point is rotated by rotating the cylindrical lens.