Apparatus for inspecting plate-like bodies

An apparatus for inspecting plate-like bodies to inspect a side surface of a plate-like body with sheeted coating materials on a top side and bottom side of the plate-like body, the apparatus comprising:

• at least one light emitting unit configured to irradiate the side surface of the plate-like body with light;
• at least one light receiving unit configured to receive light reflected with respect to the side surface of the plate-like body;
• a conveying unit configured to move at least one among the light emitting unit and the plate-like body and to vary a position of the light on the side surface of the plate-like body, emitted by the light emitting unit;
• and
• a determining unit configured to determine whether the side surface of the plate-like body has a defect, by using the light emitted by the light emitting unit, upon occurrence of a condition under which the conveying unit varies the position of the light on the side surface of the plate-like body, emitted by the light emitting unit,
• wherein the at least one light emitting unit includes a light emitting unit for first edge detection and a light emitting unit for second edge detection,
• wherein the at least one light receiving unit includes a light receiving unit for first edge detection and a light receiving unit for second edge detection,
• wherein the light emitting unit for first edge detection and the light receiving unit for first edge detection are disposed on a side of a first side surface of the plate-like body,
• wherein the light emitting unit for second edge detection and the light receiving unit for second edge detection are disposed on a side of a second side surface of the plate-like body opposite the first side surface thereof,
• wherein a straight line connecting a position of light on the first side surface of the plate-like body to be emitted by the light emitting unit for first edge detection, and a position of light on the second side surface of the plate-like body to be emitted by the light emitting unit for second edge detection, is parallel to a third side surface of the plate-like body located between the first side surface and the second side surface thereof, and
• wherein, in a case where the conveying unit moves, along a longitudinal direction of the first side surface, the position of the light on the first side surface of the plate-like body, emitted by the light emitting unit for first edge detection, while moving, along a longitudinal direction of the first side surface, the position of the light on the second side surface of the plate-like body, emitted by the light emitting unit for second edge detection, respective positions of the light including points at edges of the third side surface of the plate-like body,
• the determining unit is configured to determine that there is a defect at an edge of the third side surface of the plate-like body, upon occurrence of a condition under which a time point at which the light emitting unit for first edge detection starts receiving the light and a time point at which the light emitting unit for second edge detection starts receiving the light do not match, or a condition under which a time point at which the light emitting unit for first edge detection terminates receiving the light and a time point at which the light emitting unit for second edge detection terminates receiving the light do not match.

An apparatus for inspecting plate-like bodies to inspect a side surface of a plate-like body with sheeted coating materials on a top side and bottom side of the plate-like body, the apparatus comprising:

• at least one light emitting unit configured to irradiate the side surface of the plate-like body with light;
• at least one light receiving unit configured to receive light reflected with respect to the side surface of the plate-like body;
• a conveying unit configured to move at least one among the light emitting unit and the plate-like body and to vary a position of the light on the side surface of the plate-like body, emitted by the light emitting unit;
• and
• a determining unit configured to determine whether the side surface of the plate-like body has a defect, by using the light emitted by the light emitting unit, upon occurrence of a condition under which the conveying unit varies the position of the light on the side surface of the plate-like body, emitted by the light emitting unit,
• wherein the at least one light emitting unit includes a light emitting unit for detecting a first length and a light emitting unit for detecting a second length,
• wherein the at least one light receiving unit includes a light receiving unit for detecting a first length and a light receiving unit for detecting a second length,
• wherein the light emitting unit for detecting a first length and the light emitting unit for detecting a second length are disposed along a longitudinal direction of a first side surface of the plate-like body,
• wherein the light receiving unit for detecting a first length is disposed at a location at which light that is emitted by the light emitting unit for detecting a first length and that is reflected with respect to the first side surface of the plate-like body is to be received, and the light receiving unit for detecting a second length is disposed at a location at which light that is emitted by the light emitting unit for detecting a second length and that is reflected with respect to the first side surface of the plate-like body is to be received, and
• wherein, in a case where the conveying unit moves, from one edge of the first side surface to another edge thereof and along the longitudinal direction of the first side surface, a position of light on the first side surface of the plate-like body, emitted by the light emitting unit for detecting a first length, while moving, from one edge of the first side surface to another edge thereof and along the longitudinal direction of the first side surface, a position of light on the first side surface of the plate-like body, emitted by the light emitting unit for detecting a second length,
• the determining unit is configured to determine that there is a defect at a longitudinal edge of the first side surface of the plate-like body, upon occurrence of a condition under which a time difference between a time point at which the light receiving unit for detecting a first length starts receiving the light, and a time point at which the light receiving unit for detecting a second length terminates receiving the light, is shorter than a predetermined time period, the predetermined time period being set in accordance with a longitudinal length of the first side surface and a speed at which the conveying unit moves each of the position of the light on the first side surface of the plate-like body, emitted by the light emitting unit for detecting a first length, and the position of the light on the first side surface of the plate-like body, emitted by the light emitting unit for detecting a second length.