Device and method for checking for surface defect, using image sensor

A device for inspecting a surface defect using an image sensor, the device comprising:

• a frame part that provides a transport path of a subject in a lengthwise direction parallel to a ground;
• a transport part installed on one side of the frame part to transport the subject along the transport path;
• an image sensor unit installed in a middle of the transport path to photograph a surface of the subject from an upper side of the transported subject;
• a lighting unit including a plurality of lighting lamps, which irradiate a photographing area, which is an area belonging to the surface of the subject and photographed by the image sensor unit, with light in different directions, and installed in the middle of the transport path;
• and
• a controller that controls operations of the transport part and the image sensor unit so that the photographing area is changed by a predetermined unit transport distance at each photographing by photographing the surface of the subject while moving the subject by the unit transport distance,
• wherein the controller controls an operation of the lighting unit so that any one of the plurality of lighting lamps is turned on in a predetermined order when the image sensor unit performs the photographing and thus irradiates each photographing area consecutively photographed with each other with the light in the different directions,
• wherein the lighting unit includes:
• a first lighting module including a plurality of lighting lamps configured to irradiate the photographing area with light from a front side of the image sensor unit and installed in the middle of the transport path;
• a second lighting module including a plurality of lighting lamps configured to irradiate the photographing area with light from a rear side of the image sensor unit and installed in the middle of the transport path;
• and
• a lighting controller configured to turn on the plurality of lighting lamps included in the first lighting module and the second lighting module in the predetermined order by a control signal from the controller,
• wherein the plurality of lighting lamps provided in the first lighting module are arranged to have different horizontal incidence angles that are angles between directions in which the lighting lamps irradiate light and a transport direction of the subject, and the plurality of lighting lamps provided in the second lighting module are arranged to have different horizontal incidence angles, and
• wherein the first lighting module includes:
• a first lighting module side lamp fastening member that has a sawtooth shape in which a first inclined surface and a second inclined surface facing the photographing area are serially connected to each other in a width direction of the frame part and is installed on the front side of the image sensor unit;
• a first lighting lamp including a plurality of light emitting diode (LED) light sources that are each coupled to the first inclined surface;
• and
• a second lighting lamp including a plurality of LED light sources that are each coupled to the second inclined surface, and
• the second lighting module includes a second lighting module side lamp fastening member that has the sawtooth shape, in which a third inclined surface and a fourth inclined surface facing the photographing area are serially connected to each other in the width direction of the frame part, and is installed on the rear side of the image sensor unit, a third lighting lamp including a plurality of LED light sources that are each coupled to the third inclined surface, and a fourth lighting lamp including a plurality of LED light sources that are each coupled to the fourth inclined surface.