An insertion tool for inserting an intervertebral spacer is provided. One aspect of the invention relates to an integrated circuit die having an array of tiles arranged in columns. Dummy patterns are formed in the scribe region, which include a first dummy pattern and second dummy patterns for preventing dishing of the insulating film. An image signal processing characteristic control unit uses an output of the second line sensor as a control signal to control the processing characteristic of the image signal read by the first line sensor. The demodulation means includes a noise component removal means that removes noise components in the measurement signal through signal arithmetic processing with the pseudo-noise signal.