JPS58194004A - Superposition type phase plate - Google Patents

Abstract

PURPOSE:To superpose both phase plates on each other with high precision in such a way that their optical axes are at right angles, by linearly cutting one circular crystal plate so that its circumferential edge part is in series to the optical axis and the other so that the circumferential edge is in parallel to the optical axis, and superposing the both on each other. CONSTITUTION:Linearly cut parts 6 and 7 perpendicular and parallel to their optical axes 3 are provided to the outer circumferences of two circular phase plates 1 and 2, which are superposed on each other in such a way that the cut parts 6 and 7 are coincident with each other. For example, when crystal, etc., is used, phase plates of plase plates cut circularly are bonded together in an aligned optical-axis state to form a rod shape and cut while measured precisely by using an X-ray goniometer, so the direction of the optical axis is indicated with extremely high precision. It is easy to align straight-line edges 6 and 7 which are provided to those two phase plates 1 and 2 and have relatively large distance to each other precisely, so the optical axes of both phase plates are set precisely at right angles.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in superposed sitting phase plates, and more particularly to kneeling house type phase plates.

As is well known, in the Nieringhaus type phase plate, for example, the thickness difference between the two crystal plates is equal to the thickness of the zero-order A wavelength plate, and each optical axis is 1 [! By superimposing them so as to have Q, a pseudo wave plate having a zero-order thickness on an equal screen is obtained.

This type of wave plate has a relatively large plate thickness, so it is easy to add F of the crystal plate, and it has sufficient strength as a wave plate, so it has good characteristics as a wave plate. It is something that can be obtained.

However, when manufacturing this, it is necessary to be careful not to misdirect the optical axis, especially when setting the assembly to 1°, and this is especially true when manufacturing a small number of units, and when producing in large numbers. This was one of the factors that hindered production efficiency. .

The present invention has been made in order to solve the above-mentioned problems, and provides an overlapping seat plate in which the peripheral edges of crystal plates processed into a circular shape are aligned and overlapped to achieve desired characteristics. Let 1 be the target.

Hereinafter, the present invention will be explained in detail in comparison with a conventional method of assembling a phase plate.

First, as a method for indicating the direction of the optical axis of a conventional phase plate, as shown in FIGS. 1(a) to (C), the direction of the optical axis 3 and the optical In the direction perpendicular to the axis (either provide two small grooves m4 and 5 and overlap them so that a coincides with each other, or provide two phase plates 1 and 2 with a4 and 5 in the direction of the optical axis 3, respectively, so that the grooves are perpendicular to each other) or at a predetermined angle with the optical axis 3.

For example, various methods have been used, such as providing grooves 4 and 5 in the 45° direction and overlapping them so that they coincide.

However, in any of these methods, it is not easy to obtain the positional accuracy of the grooves, and it is also difficult to ensure that the optical axes are orthogonal. In particular, the grooves are provided at a predetermined angle with the optical axis as shown in Figure 1 (C). When this method is used, and it is necessary to coat one side of each of the phase plates 1 and 2 with an anti-reflection film, the coating has to be specified, which has the disadvantage that a great deal of care is required in the coating process. In order to solve the above-mentioned drawbacks, in the present invention, as shown in FIG. 2, straight cut portions 6 and 7 are provided on the outer periphery of the two circular phase plates 1 and 2, perpendicular and parallel to the optical axis 3, respectively. , the cant portions 6 and 7 are aligned and overlapped.

The above-mentioned processing is performed by precision measurement using an S-shape t=-r Since it is possible to cut while making a corner, it is possible to specify the direction of the optical axis extremely precisely.

Also, since it is easy to precisely align the relatively long straight edges 6 and 7 provided on the two phase plates 1 and 2, the optical axes of both phase plates must be precisely (=orthogonal to each other) Can be done.

Although it is common practice to apply an anti-reflection coating to the non-adhesive surface of such a phase plate to increase the efficiency of light energy use, it is not necessary to specify the coating, and it is not necessary to use coach ink. Therefore, there is no need to pay particular attention to the coating process.

Since the present invention is constructed as described in 1-1 below, it has extremely good characteristics as compared to the conventional stacked phase plate (2) since it ensures that the optical axes of both phase plates constituting this are orthogonal with high precision. It exhibits a remarkable effect in improving the yield of phase plates.

Furthermore, since there is no need to pay particular attention to the steps of anti-reflection coating and adhesion, it also has the effect of reducing the number of man-hours by 2, and thus the manufacturing cost.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are diagrams each illustrating optical axis indicating means of a conventional stacked phase plate, and FIG. 2 is a diagram illustrating the optical axis indicating means of the present invention. . 1.2...Crystal plate, 3...Optical axis. 6.7... Straight cut edge of crystal plate Patent applicant: Toyo Tsushinki Co., Ltd. ” Japan Patent Office ゛ (Kamo 2m1, Indication of the case 1982 Patent Application No. 771692, Title of invention Overlapping type phase plate 3, Person making amendment Related to the case Patent issue 1 Submitted person 5, Number of inventions increased by amendment None 6. Subject of amendment Brief description of the drawings 7. Contents of the amendment As shown in the attached appendix, the content of the amendment "Brief description of the drawings" is amended as follows: "4. Drawings A simple explanation of Figure 1 (al to (5) respectively...)
Let's say ``Simple 'fJ of 4 drawings, Explanation Figure 1 (a) to (cl are each...'').7

Claims (1)

[Claims] A predetermined thickness difference is created between two crystal plates, the optical axes of the two crystal plates are superimposed to be perpendicular to each other, and the light that passes through them is split into an ordinary ray and an anomalous ray. In a phase plate of the type that provides a phase difference of A superimposed phase plate characterized by overlapping the cut edges with their edges aligned.