Surface inspection apparatus and surface inspection method

1. A surface inspection apparatus which inspects a plurality of surfaces formed in a peripheral edge portion of a plate-like object, the apparatus comprising:

a photographing mechanism, which photographs the peripheral edge portion of the plate-like object having a plurality of surfaces; and

an image processing device, which processes an image obtained by the photographing mechanism;

the photographing mechanism including an optical system which guides images of the plurality of surfaces of the plate-like object in one direction, and a camera unit having an image pickup surface, on which the images of the plurality of surfaces guided by the optical system in the one direction are formed;

wherein the peripheral edge portion of the plate-like object includes a circumferential surface of the plate-like object, a first tapered surface formed by chamfering a first edge portion made by the circumferential surface and a first surface of the plate-like object, and a second tapered surface formed by chamfering a second edge portion made by the circumferential surface and a second surface of the plate-like object; and

the optical system includes a first guide mirror which reflects an image of the first tapered surface and guides the image to the camera unit, a second guide mirror which reflects an image of the second tapered surface and guides the image to the camera unit, and a compensating lens which is mounted between the camera unit and the circumferential surface and forms the image of the circumferential surface on the image pickup surface of the camera unit.

2. The surface inspection apparatus according to claim 1 , wherein the optical system includes a direction changing mirror, which reflects the images guided through the first guide mirror, the second guide mirror and the compensating lens in a predetermined direction; and

the images reflected by the direction changing mirrors are formed on the image pickup surface of the camera unit.

3. The surface inspection apparatus according to claim 1 , further comprising a turntable on which the plate-like object is mounted, and which rotates the plate-like object.

4. A surface inspection method for inspecting a circumferential surface of a plate-like object, a first tapered surface formed by chamfering a first edge portion made by the circumferential surface and a first surface of the date-like object, and a second tapered surface formed by chamfering a second edge portion made by the circumferential surface and a second surface of the plate-like object, the method comprising:

forming an image of the first tapered surface on an image pickup surface of a camera unit by reflecting the image with a first guide mirror

forming an image of the second tapered surface on the image pickup surface of the camera unit by reflecting the image with a second guide mirror; and

forming an image of the circumferential surface on the image pickup surface of the camera unit by compensating the image by a compensating lens mounted between the camera unit and the circumferential surface.

5. The surface inspection method according to claim 4 , wherein the plate-like object is rotated, when the images of the circumferential surface, the first tapered surface, and the second tapered surface are formed on the image pickup surface of the camera unit.

6. The surface inspection apparatus according to claim 1 , further comprising:

a third guide mirror which reflects an image of a peripheral edge portion upper surface of the plate-like object and guides the image to the camera unit,

a fourth guide mirror which reflects an image of a peripheral edge portion lower surface of the plate-like object and guides the image to the camera unit, and

a compensating lens which is mounted between the camera unit and the peripheral edge portion upper surface of the plate-like object, and between the camera unit and the peripheral edge portion lower surface of the plate-like object, respectively, and forms the images of the peripheral edge portion upper and lower surfaces on the image pickup surface of the camera unit.