JPS60175015A - Optical axis adjusting method - Google Patents

Abstract

PURPOSE:To adjust an optical axis easily and accurately by adjusting inclination of a main photodetector in accordance with outputs from optical axis adjusting photodetectors attached around the main photodetector. CONSTITUTION:Inclination in the vertical direction of a light receiving means 1 is detected by optical signals which are converged by optical axis adjusting light receiving lenses 13 and 13a, and this inclination is corrected by a vertical- direction adjusting circuit. Inclination in the horizontal direction of the means 1 is detected by outputs of optical axis adjusting light receiving lenses 27 and 28 and is adjusted by a horizontal-direction adjusting circuit. Signals of lenses 13, 13a, 27, and 28 are added by an adding circuit, and the result is outputted to a display circuit.

Description

TECHNICAL FIELD The present invention relates to a method for adjusting the optical axes of a light projecting means and a light receiving means.

BACKGROUND ART For example, when a light receiving means is arranged at a distance of 10 m or several hundred meters from a light projecting means, if the angle of the optical axis of the light receiving means deviates even slightly, the travel distance of the light path from the projector becomes large. It was very hot.

Therefore, the optical axis of the light receiving means is set to s, 1. + A light receiving means that can be adjusted is desired.

Purpose It is an object of the present invention to provide an optical axis adjustment method that can easily adjust the optical axes of a light projecting means and a light receiving means to a positive 41 ft' VC.

Embodiment FIG. 1 is a diagram showing an embodiment of the light receiving means l constructed according to the present invention. The light projecting means 2 irradiates the light receiving means 1 with infrared rays having a light lpHl13 and a luminous flux 4. The light projecting means 2 sends out a coded optical signal, and the light receiving means 1 decodes the optical signal. In this way, the optical signal from the light projecting means 2 is transmitted to the light receiving means l.

The light projecting means 2 sends out a normal optical signal instead of a coded optical signal, and when a moving object (not shown) passes by, the light receiving means 2 detects the moving object. Good too.

FIG. 2 is a front view of the light receiving means l, and a simplified sectional view taken from the section line at-tu in FIG. 3 Fi+42. The support plate 5 has a focusing lens 6.

The light incident on the focusing lens 6 is irradiated onto the main light receiving element 7. An electrical signal having a level corresponding to the amount of light received by main light receiving element 7#i is derived. The optical axis of the optical system consisting of the focusing lens 6 and the main light receiving element 7 is indicated by reference numeral 8. The present invention achieves that the optical axis 3 of the light projecting means 2 and the optical axis 8 of the optical system comprising the focusing lens 6 and the main light receiving element 7 are aligned on a straight line.

The support plate 5 has four optical systems 9, 1 having the same configuration.
0, 11.12 are arranged. The optical system 9 includes a light receiving lens 13 for adjusting the optical axis and a light receiving element 14 for adjusting the optical axis. The optical axis adjustment light receiving element 14 outputs four electrical signals having levels corresponding to the amount of received light. The optical axis of the light receiving lens 13 for adjusting the optical axis is indicated by reference numeral 15. optical axis m
The light-receiving end face 1 of the light-receiving element 14 for adjusting the optical axis is located at the imaging position when a ray parallel to the optical axis 15 enters the light-receiving lens 13 for adjusting the optical axis.
There are six. The centroid 17 of the light-receiving end surface 16 is arranged offset from the optical axis 15, as shown in FIG. Optical axis 8 and optical axis 15 are parallel. Optical axes 8, 1 centering on optical axis 8
A portion 18 of the light-receiving end face 16 that is perpendicular to the optical axis 8 with a radius of 5 and that is radially inward of the gc imaginary circle in the plane that includes the light-receiving end dJJ16 is the light-receiving end face 16 outside the imaginary circle. is larger than the remaining portion 19 of . The centroid 17 lies in the plane containing the optical axis 8.15. In front of the light-receiving lens 13 for adjusting the optical axis, a mask 24 is arranged which can freely change the diameter of a relatively small aperture 230 centered on the optical axis 15.

Similarly, the optical system IO also includes a light receiving lens 13a for adjusting the optical axis,
Corresponding parts of the optical system 9 are indicated with a subscript a.

The remaining optical systems 11 and 12 have the same configuration as the optical systems 9 and 10, and as shown in the second figure, have masks 25 and 26 similar to the mask 24, and are used for adjusting the optical axis. It has light-receiving lenses 27 and 28 for optical axis adjustment similar to the light-receiving lens 13.

The optical axis 15 of the light-receiving lens 13 for optical axis adjustment and the optical axes of the light-receiving lenses 13a, 27.28 for optical axis adjustment are parallel to the optical axis 8, and spaced apart by 90 degrees around the optical axis 8. Placed.

The procedure for adjusting the optical axis will be explained below with reference to FIG. The light projecting means 2 is displaced to a position indicated by an imaginary line 31 and fixed at a fixed position so that the optical axis 3 of the light projecting means 2 becomes an ideal optical axis 30. Next, the light receiving means 1 is fixed at the position shown by the imaginary line 32 so that the optical axis 8 of the light receiving means 1 coincides with the ideal optical axis 30. This causes the optical axes 8 and 30 to coincide. Optical axis 3
The light intensity distribution having , is symmetrical within a plane 1α perpendicular to the optical axis 3, as indicated by reference numeral 34 on the reference line 33 perpendicular to the optical axis 3.

Referring to FIG. 6, the aperture 23 of the mask 24,248 is
, 23a are narrowed down. The light that covers the aperture 23.23a is received by the light receiving element 14.degree. 14a for optical axis m. The light-receiving layer of the light-receiving element 14 for optical axis adjustment in the armor shown in FIG. 6 is shown in FIG. When the aperture 23 is small, all of the incident light beam is incident on the light receiving element 14. Optical axis adjustment light receiving element 14 and optical axis adjustment light receiving element 14. The light projecting means 2 is moved to the y position and brought to the position shown by the imaginary line 31 so that the output level of a is the same.

Hypothetical light receiving means 2 with reference to FIG. 8! The aperture 23.23a of the mask 24.24a is fully opened in order to bring the mask 24.24a to the position indicated by 32 and align the optical axis 8 with the ideal optical axis 30. The aperture 23.23a of the mask 24.24a is enlarged to allow all the light beams incident on the optical axis adjustment light receiving lens 13.13aiC to be incident on the optical axis adjustment light receiving element 14.14a. When the light receiving means 1 is tilted in the direction indicated by reference numeral 40, the light beam incident on the optical axis adjustment light receiving element 14 is deviated as shown in FIG. 9 due to the influence of aberration. At this time, the light receiving element 14a for adjusting the optical axis receives all the light flux that is incident on the light receiving lens 14a for adjusting the optical axis because the upper part thereof is longer than the light receiving element 14 for adjusting the optical axis.

Therefore, the amounts of received optical signals incident on the optical axis adjustment light receiving elements 14 and 14a are different. Light receiving element for optical axis adjustment 14.1
The optical axis 8 of the light receiving means 1 can be made to coincide with the ideal optical axis 30 by displacing the angle of the light receiving means 1 so that the amount of light received by the light receiving means 4a becomes 1-1.

When the light receiving means 1 is tilted in the direction indicated by reference numeral 41, the amount of light received by the light receiving element L4aK for optical axis adjustment is smaller than the amount of light received by the light receiving element 14 for adjusting the optical axis. By matching the amount of light received by both, the optical axis 8 of the light receiving means 1 can be made to match the ideal optical axis 30.

As described above, the light receiving means 1 is
However, the operation of adjusting the horizontal tilt of the light receiving means l using the outputs of the optical systems 11 and 12 is the same as that for the optical systems 9 and 10.

FIG. 1O is a block diagram showing the configuration of the light receiving means 1. As shown in FIG. The optical system 1a has a support plate 5, a focusing lens 6, and a light receiving lens 13.13a for optical axis adjustment, 27°28. The reed optical system 1a has an optical axis Ill# light receiving lens 1 for festival light receiving.
The optical signals focused by 3a, 27, 28, respectively, are converted into electrical signals and output via lines 11-1!4, respectively. The differential circuit lb calculates the difference between the signals from the optical axis adjusting light receiving lenses 13 and 13a inputted via lines 11 and 12. The result requested by the differential circuit 1bK is input to the vertical adjustment circuit 1c.

The vertical direction determination circuit 1c determines the vertical direction inclination of the light receiving means 1 based on the output from the differential circuit 1b. The vertical direction adjustment circuit 1d adjusts the light receiving means 1 in the vertical direction in response to the output from the vertical direction determination circuit 1c. The vertical direction determination circuit 1c also outputs the determination result to the display circuit 1e.

The differential circuit 1f is connected to the line I! 3. Calculate the difference between the signals of the optical axis adjustment light receiving lenses 27 and 28 inputted through /4. The horizontal direction determination circuit 1g determines the horizontal direction inclination of the light receiving means 1 based on the signal from the differential circuit 1f. The horizontal direction of the light receiving means l is adjusted by the output from the horizontal direction adjustment circuit lhI''i and the horizontal direction determination circuit 1g.
I will appear on e.

Addition circuit 1iij, light receiving lens for optical axis adjustment 13° 13a
, 27. Add the signals from 28. The addition circuit 1i also outputs the addition result to the display circuit 1e.

The operation of the light receiving means 1 will be explained below using FIG. 1θ. The vertical tilt of the light receiving means 1 is detected by the optical signal focused by the optical axis adjustment light receiving lens 13.13a, and the vertical direction adjustment circuit 1d corrects the vertical tilt of the light receiving means 1. Also, light receiving lens 2 for adjusting light +11111
The horizontal inclination of the light receiving means l is determined based on the appearance of 7.28. After detecting the horizontal tilt of the light receiving means l,
The horizontal direction adjustment circuit 1h adjusts the horizontal direction inclination of the light receiving means l. Further, the vertical and horizontal inclinations are displayed by the display circuit 1e, and the inclination of the light receiving means 1 may be corrected manually. The adding circuit 1i can increase the amount of light received by the light receiving means 1 by adding the signals from the light receiving lenses 13.13a and 27.28 for adjusting the optical axis. After being added by the adding circuit 11, the display circuit 1e
Output the calculation result by.

As described above, after adjusting the aperture to a smaller size and setting the optical axis of the light projecting means, the aperture is made larger and the optical axis of the light receiving means is set, so that the optical axis can be set accurately.

In the above embodiment, the distance 1 between the optical axes 15, 15a and the distance fM8 is
Although 46 P Q (see FIG. 3) were the same value, different f values may be used in other embodiments.

When the distance PQ is set to a different value, the light receiving element 14 for adjusting the optical axis
．． 14a is the light receiving means 1 so as to have a predetermined value.
, adjust the light projecting means 2.

In the embodiment described above, infrared light is emitted from the light projection means 2, but other light may be used as long as it has a wavelength different from that of natural light.

Effects As described above, according to the present invention, the light-receiving element for adjusting the light 1lIlII is arranged around the main light-receiving element, and the inclination of the main light-receiving element is adjusted by the output from the light-receiving element for adjusting the optical axis. The optical axis can be adjusted to 8 easy and positive (11).

[Brief explanation of drawings]

1 is a diagram showing an embodiment of the light receiving means 1 constructed according to the present invention, FIG. 2 is a front view of the light receiving means 1, and FIG. 3 is a simplified view of the cutting curve 111-II in FIG. 2. FIG. 4 is a front view of the light receiving element 14 for adjusting the optical axis.
FIG. 5 is a diagram showing the operation of the light receiving means 1 and the light projecting means 2;
FIG. 6 is a diagram showing the operation when adjusting the light projecting means 2, FIG. 7 is a simplified side view of the light-receiving lens 13 for adjusting the optical axis and the light-receiving element 14 for adjusting the optical axis, and FIG. 8 is a diagram showing the light-receiving means. FIG. 9 is a simplified side view of the optical axis adjustment light receiving lens 13 and the optical axis adjustment light receiving element 14, and FIG. 1θ is the configuration of the light receiving means 1. FIG. l... Light receiving means, 2... Light projecting means, 13, 13a. 27.28 ・Light receiving lens for light sleeve adjustment festival, 14, 14a・
...Photo-receiving element for optical axis adjustment Figure 2 Figure 3 Figure 4 Figure 6 Figure 7 Figure 8, /4 Figure 10 Procedural amendment document September 25, 1980 Patent application 1982-30764 2, Name of the invention: Optical axis adjustment method 3, relationship with the case of the person making the amendment Applicant address name (583) Matsushita Electric Works Co., Ltd. Representative Nagisa 4, agent address 38 Nishihonmachi 1-chome, Nishi-ku, Osaka Shin-Nisan Building Country equipment EX 0525-5985 INi'APT
J International FAX GIIl&GII (06)538-
02476, Detailed explanation of the invention column 7 of the specification to be amended, contents of the amendment No. io*fjS, lines 2 to 3, 1 t calculation result'' is corrected to ``result of accrual'' do. that's all

Claims (1)

[Scope of Claims] A plurality of optical axis adjustment light receiving elements capable of receiving light from a light source are arranged around the outer periphery of the main light receiving element whose optical axis is to be adjusted. The light-receiving element for optical axis adjustment derives an electrical signal having an output level corresponding to the amount of received light, and the relationship between the output levels from the light-receiving element for optical axis adjustment is in a predetermined state. An optical axis adjustment method characterized by displacing a main light receiving element and an optical axis adjustment light receiving element so that