JPS6236531A - Measurement of optical lens characteristic and its apparatus - Google Patents

Abstract

PURPOSE:To enable simple detection of a focus of an optical lens for optical transmission, etc. without giving damage to the lens, by inspecting coincidence of the reference pattern image and a pattern image formed by a specimen lens. CONSTITUTION:The standard lens is placed in a position of a specimen lens 3 in place of the specimen lens; natural or room illuminating light is irradiated from the left side of a screen 1 and positions of screens 1, 2 are fixed at the distances of f1', f2' from the standard lens respectively. Next, the specimen lens 3 is placed instead of the standard lens and a carriage is displaced in the direction shown by the arrow to inspect it visually from the right side of a screen 2 to verify that focuses of the standard lens coincides with that of the specimen coincide by coincidence of the pattern on the screen 2 and that on the screen 1. Rapid identification can be made whether the specimen lens is within the allowable range or not be the overlapping condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] A method and apparatus for measuring characteristics of an optical lens for optical communication, comprising: disposing a measuring lens on a movable support of a measuring device calibrated in advance with a reference lens; The difference in characteristics between the reference lens and the measurement lens is tested in a non-contact manner by moving the support.

[Industrial application field]

The present invention relates to an optical lens characteristic measuring method and apparatus capable of verifying the difference in characteristics between a reference lens and a lens to be measured without causing equivalent damage to the lens. The present invention relates to an optical lens characteristic measuring method and apparatus that makes it possible to easily determine whether or not a lens to be measured is within a predetermined error by verifying coincidence with a pattern image formed by the present invention.

In order to check the quality of optical lenses used in optical communications and the like during acceptance inspections, it is desired to provide a measuring instrument that can perform simple and quick inspections and does not cause damage to the lenses to be measured.

Generally, when inspecting an optical lens, the curvature and refractive index of the lens are measured, but these methods require large-sized equipment and require time for measurement. Therefore, it is desired to provide a method and apparatus for measuring optical lenses that are easy to use and can be measured quickly in acceptance inspections and the like.

[Conventional technology]

In order to verify the shape, 2, curvature, material, etc. of a lens, high-precision measuring devices, typified by a refractometer, have been proposed. Such a high-precision measuring device is complicated to handle during measurement and is expensive. On the other hand, there is a method of measuring focal length as a simple measuring method. However, in order to measure the focal length, a collimated light source is required, and it is also necessary to actually measure the distance from the lens end face to the focal point. In order to accurately measure the focal length, it is also necessary to bring a gauge into contact with the end face of the lens.

[Problem that the invention seeks to solve]

In this conventional method, the apparatus becomes large and expensive, and handling is not only complicated, but also there is a risk of damaging the surface of the lens to be measured.

The present invention was created with these points in mind, and an object of the present invention is to provide a method and device for measuring optical lens characteristics that can easily test the focus of an optical lens used for optical communication, etc., without damaging equivalent lenses. It is an object.

[Means for solving problems]

FIG. 1 shows a principle diagram of the optical lens characteristic measuring device of the present invention.

In FIG. 1, 1 and 2 indicate semi-transparent screens on which patterns are printed. 3 indicates the measurement lens;
It is configured to be movable between the screens 1 and 2 in the direction shown by arrow 4 by means of a moving table (not shown). In addition, in the figure f, ',
f2' indicates the focal length from the measuring lens 3 to the screen 1.2, respectively.

[Effect]

4 instead of a measurement lens! A quasi-lens is placed at the position of the measurement lens 3, and natural light or indoor lighting is irradiated from the left side of the screen l, and f, ', f2 are measured from the standard lens, respectively.
The positions of screens 1 and 2 are fixed at focal positions at a distance of . Next, a measuring lens 3 is placed in place of the standard lens, and a moving table (not shown) is moved in the direction shown by arrow 4 to visually check from the right side of the screen 2 to check whether the pattern on the screen 2 matches the pattern on the screen 1. Verify. When the focal points of the standard lens and the lens to be measured are the same, the patterns on the screens 1 and 2 overlap with each other by movement of the movable table, so that the measurement lens can be easily verified. Furthermore, it can be quickly determined from the degree of overlap whether the lens to be measured is within the allowable range. Note that by using a movable table, there is no need to firmly fix the lens, and the lens surface is prevented from being scratched.

〔Example〕

FIG. 3 shows an embodiment of the present invention, in which parts having the same functions as those shown in FIG. 1 are designated by the same reference numerals. In the figure, numerals 1 and 2 are translucent screens on which patterns as shown in FIG. 1 are printed. Also,
Reference numeral 3 denotes a lens to be measured, which is placed on a movable table 9. 8
is a bellows, which maintains light-shielding properties and protects the screen holder 7.
It is configured to be expandable and retractable in response to a change in the relative position between the movable table 9 and the movable table 9. Reference numeral 6 denotes a magnifying lens, which is provided to facilitate confirmation of the degree of overlapping of patterns on the screens 1 and 2 and the focal position. When operating this device, a standard lens is placed at the position of the measuring lens 3 on the movable table 9, natural light or room lighting is irradiated from the left side of the screen 1, and the position of the screen 1.2 is set at the focal position of the standard lens. Fix it. Next, the measurement lens 3 is placed on the movable table 9 instead of the standard lens, and the magnifying lens 6 is moved while the movable table 9 is moved in the direction shown by the arrow 4 using the handle 9A.
Visually check the pattern on screen 2 from the right side of
Verify the match with the pattern on screen l. When the focal lengths of the standard lens and the lens 3 to be measured are the same, the patterns on the screens 1 and 2 overlap with each other by movement of the movable table 9, so that the measurement lens 3 can be easily inspected.

Furthermore, it can be quickly determined from the degree of overlap whether the lens to be measured is within the allowable range.

FIG. 2 is a principle diagram of another embodiment of the present invention, which uses a screen 1' on which relatively small black dot marks are drawn and an adjustment means (variable pinhole) 5 that can adjust the pinhole diameter. This is different from that shown in FIG. During operation, the left and right focal positions f of the standard lens are adjusted in the same way as shown in Figure 1.
, ", f2", place the screen 1' and the adjustment means 5, and then adjust the pinhole diameter, and the pattern on the screen 1' makes it appear that the amount of light passing through the pinhole is reduced compared to the monitoring position on the right side of the adjustment means 5. Fixing the adjustment means in position. Next, instead of the standard lens, a 3° lens to be measured is placed on a moving table (not shown), and the moving table is moved in the direction indicated by 4'' in the figure to monitor the state of the amount of passing light at the monitoring position. Similar to the one shown in Fig. 1, it is possible to inspect the characteristics of the lens to be measured, especially the difference in focus from the standard lens.In addition, the pinhole diameter can be adjusted in place of the screen 2 shown in Fig. 13. By using possible adjustment means 5, the present principle can be easily implemented.

〔Effect of the invention〕

As described above, according to the present invention, the focus of an optical lens used for optical communication etc. can be easily and quickly verified without damaging the equivalent lens, and is extremely useful in practice.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram of an optical lens characteristic measuring device according to the present invention, FIG. 2 is a principle diagram of another embodiment of the present invention, and FIG. 3 is a side sectional view of an embodiment of the present invention. In FIG. 3, 1.2 is a screen, 3 is a lens to be measured, 6 is a magnifying lens, 7 is a screen holder, 8 is a bellows, and 9 is a moving table. 1-) of the first day of publication
Figure 2

Claims (4)

[Claims] (1) A predetermined relationship is set between the light pattern incident on the standard lens and the light pattern transmitted through the standard lens, and the same light pattern as the light pattern incident on the standard lens is measured. An optical lens characteristic measuring method comprising: measuring the characteristics of the lens to be measured based on the difference between a light pattern that is incident on a lens and transmitted through the lens to be measured and the set standard lens transmission pattern. (2) an optical pattern generator (1, 1'); an optical pattern receiver (2, 5) movable relative to the optical pattern generator (1, 1'); and an optical pattern generator (1). , 1') and a light pattern receiver (2
, 5), a mechanism (9) for movably disposing a standard lens or a lens to be measured between the lenses, and a mechanism (9) for setting a predetermined relationship between the incident light pattern on the lens and the transmitted light pattern from the lens. An optical lens characteristic measuring device comprising: means (9A) for measuring the characteristics of an optical lens. (3) Optical lens characteristic measurement according to claim 2, wherein the optical pattern generator (1, 1') and the optical pattern receiver (2, 5) have the same pattern. Device. (4) The optical lens characteristic measuring device according to claim 2, wherein the light pattern image receptor (5) is a variable pinhole.