METHOD AND DEVICE FOR INSPECTING PATTERN MEMBER

PURPOSE:To effectively inspect a foreign matter even in the case of plural colors by irradiating a pattern member with light including respective light components, separating reflected detecting light at least to two colors, selecting the maximum signal value of the color and comparing the selected value with a reference value. CONSTITUTION:The surface of a color filter 10 is irradiated obliquely from above with a white laser beam (whose diameter is set smaller than the width of a light shielding pattern) 33 which is S-polarized. In the case that a defect, a projection caused by the foreign matter, exists in the pattern of the filter 10, reflected scattered light 34 includes the light of the P-polarized component. The light 34 is received and detected from a vertical direction and transmitted to a color separation means 40. The light is separated to blue, green and red by dichroic mirrors 41-43 and photo- electrically converted 51-53 respectively to be transmitted to a selection circuit 70. A selection circuit part 72 selects the maximum signal value out of the three colors and outputs it to a comparison and decision circuit 90. A reference value generation circuit 80 outputs the reference value of the pattern of the color corresponding to the maximum signal value in accordance with a control signal from a comparison circuit part 71 to the circuit 90. The circuit 90 compares an inputted signal, and when the detection signal is larger than the reference value, it is decided as the defect.