SEAL INSPECTING METHOD

PURPOSE:To automate inspection by removing bubbles on surfaces of bodies to be inspected arrayed in a plane in a transparent liquid, scanning them with a line image sensor, and discriminating a defective body by a bubble output. CONSTITUTION:When a sensor drive switch is turned on, an ultrasonic-wave generator 3 is driven for a certain time and bubbles sticking on the surface of a body 6 to be inspected is removed. Then, after the set time of an off-delay timer 12 and an on-delay time 13, a sensor driving circuit 14 starts drive and outputs of respective picture elements from a line image sensor element 15 are outputted on time-division basis and amplified by an amplifying circuit 16. If the body 6 to be inspected has a defective, leaking air forms a bubble F, which moves up in a transparent liquid. When the bubble F enters into the visual field of the sensor device, the picture element output which corresponds to the position of the bubble decreases in level. This output is supplied to a discriminating circuit 17, which outputs a pulse which corresponds to the low-level part of the amplification output, driving a warning device 18 is response to the rise of the pulse.