Method and apparatus for measuring thickness of thin article
AssigneeHon Hai Precision Industry Co., Ltd.
InventorJhy-Chain Lin
Life of this patent
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Abstract
An apparatus (100) for measuring a thickness of a thin article according to an embodiment of the present apparatus is provided. The apparatus includes an optical fiber interferometer (101), a signal processor module (102) and a measuring module (103). The optical fiber interferometer is configured for obtaining an optical distance difference. This optical distance difference is a result of the thickness of the thin article between a first optical path in which the thin article is measured and a second optical path. The signal processor module is configured for converting an optical distance difference into a phase difference and processing the optical distance difference to obtain a linear signal. That linear signal is convertible into a thickness value of the thin article.
Claims14
An apparatus for measuring a thickness of a thin article comprising an optical fiber interferometer, the optical fiber interferometer being configured for obtaining an optical distance difference caused by the thickness of the thin article, the optical distance difference between a first optical path in which the thin article is measured and a second optical path, the optical fiber interferometer comprising:
- a laser light source adapted for providing a light beam to the optical coupler;
- an optical coupler configured for splitting the light beam into a first light and a second light;
- a first optical fiber coupled to the optical coupler, the first optical fiber being configured for transmitting the first light;
- and
- a second optical fiber coupled to the optical coupler, the first optical fiber being configured for transmitting the second light;
- and
- a signal processor module configured for converting the optical distance difference into a phase difference and for processing the optical distance difference to obtain a linear signal, the linear signal being convertible into a thickness value of the thin article.
The apparatus as described in claim 5, wherein the measuring module further comprises a supporter configured for securing the adjustable plane.
A method for measuring a thickness of a thin article, comprising:
- preparing a first optical path and a second optical path, the first optical path and the second optical path being coupled to each other at a certain point, both the first optical path and the second optical path ending at the certain point;
- providing a first light and a second light, respectively, transmitting in the first optical path and the second optical path, the first light and the second light interfering at the certain point;
- modulating at least one of the first light and the second light for making the at least one of the first light and the second light coherent and in phase at the certain point;
- settling the thin article into the first optical path in order to change an optical distance that the first light is traveled in the first optical path, a phase difference being created between the first light and the second light at the certain point;
- at least one of modulating and changing at least one phase of the first light and the second light to obtain an optical interference signal, the optical interference signal containing an information of a thickness value of the thin article;
- and
- processing the optical interference signal to obtain a linear value of the thickness of the thin article.
Dependencies are inferred from the claim text.