Apparatus for inspecting object surface

Patent metadata

Field	Value
Publication number	US-10852243-B2
Application number	US-201816120551-A
Country	US
Kind code	B2
Filing date	Sep 4, 2018
Priority date	Jan 15, 2018
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

An apparatus for inspecting object surface according to an embodiment includes: an imaging device including an imaging area; an optical source; and a group of optical devices including a mirror and a lens, and causing a reflected light other than a regular reflection light from an object to be reflected by a mirror surface of the mirror, and to form an image in the imaging area of the imaging device through the lens, the regular reflection light being caused by a light incident to a surface of the object from the optical source, wherein the optical source, the mirror, the lens, and the imaging device are arranged in such a manner that the regular reflection light is not incident to the imaging area of the imaging device through the mirror and the lens.

First claim

The invention claimed is:

1. An apparatus for inspecting an object surface comprising:
an imaging device including an imaging area;
an optical source;
a first partial transmission device including a transmission portion in a central part, a part of a light emitted from the optical source passing through the transmission portion;
a second partial transmission device including a light interception portion in a central part;
a first lens disposed on one side of the first partial transmission device opposite from the optical source;
a second lens, a third lens, and a fourth lens having a common optical axis, the second lens being disposed between the third lens and the fourth lens, an optical axis of the first lens intersecting with a line connecting a center of the second lens to a center of the fourth lens; and
a half mirror disposed between the second lens and the fourth lens; wherein:
the first lens is disposed separate from the first partial transmission device at a focal length of the first lens;
the half mirror reflects a light from the first lens and propagates the light to the second lens;
the second lens propagates the light propagated from the half mirror to the third lens;
the third lens causes the light propagated from the second lens to be incident to a surface of an object and propagates a light reflected at the surface of the object to the second lens;
the second lens propagates the light reflected at the surface to the half mirror;
the half mirror passes the light propagated from the second lens and propagates the light to the fourth lens;
the fourth lens causes the light propagated from half mirror to form an image in the imaging area of the imaging device through the second partial transmission device; and
the light interception portion of the second partial transmission device blocks a regular reflection light in the light reflected at the surface of the object.

2. The apparatus according to claim 1 , wherein:
a distance between the second lens and the third lens is equal to a sum of a focal length of the second lens and a focal length of the third lens;
a distance between the second lens and the fourth lens is equal to a sum of the focal length of the second lens and a focal length of the fourth lens; and
a distance between the fourth lens and the second partial transmission device is equal to the focal length of the fourth lens.

3. The apparatus according to claim 1 , wherein:
f 1 denotes a focal length of the first lens;
f 4 denotes a focal length of the fourth lens;
r 1 denotes a radius of the transmission portion of the first partial transmission device;
r 4 denotes a radius of the light interception portion of the second partial transmission device; and
the following relationship expression is satisfied:
r 1 :r 4 =f 1 :f 4 .

4. The apparatus according to claim 1 , further comprising an image processor that obtains a surface information of the object based on the image formed by the imaging device.

Assignees

• Toshiba Kk

Inventors

• Kamikawa Takahiro
• Ohno Hiroshi
• Hato Takehiro

Classifications

• G01N21/8806 Primary

  Specially adapted optical and illumination features · CPC title

• G01N2201/0636

  Reflectors · CPC title

• G01N21/47

  Scattering, i.e. diffuse reflection (G01N21/25, G01N21/41 take precedence {G01N21/55 takes precedence}) · CPC title