Abstract
A display substrate tester and a method thereof are provided to enhance the accuracy of a visual inspection by automatically producing the height of a protrusion formed on a display substrate. A display substrate tester(100) comprises a light source part(120), an image pickup part(130) and a measuring part(140). The light source part(120) emits light and provides it to a display substrate(200) on which a color filter layer is formed and which reveals a specific color using the light provided from the light source part(120). The image pickup part(130), such as a camera, etc., installed at the upper part of the light source part(120), photographs a protrusion area, where a protrusion is formed on the display substrate(200), and a peripheral area, which encloses the protrusion area, and creates a test image. The measuring part(140) receives the test image from the image pickup part(130), produces the color coordinate value of the protrusion area and the color coordinate value of the peripheral area on the basis of the test image, and obtains the height of the protrusion.