Abstract: The circuit comprises an amplitude setting transistor 5Q for controlling the amplitude of high-frequency current I2QB flowing through the second current mirror circuit 2, by using an input of reference direct current signal Bias. Direct current component I4QB generated based on reference direct current signal Bias is subtracted from direct current I1 flowing through the other side line of the first current mirror circuit 1. In this case, level fluctuation of driving current IZ can be significantly suppressed, since the increment of the direct current component included in high-frequency current I2QB is proportional to direct current component I4QB which is subtracted from direct current I1 flowing through said other side line of the first current mirror circuit 1.

Abstract: An apparatus comprises a fiber optic device having a plurality of cores buried in a cladding, a first luminescent screen fixed to an input face of said fiber optic device, and a first CCD image sensor fixed to an output face of the fiber optic device. The CCD image sensor comprises a package, a CCD chip fixed in the package, lead pins penetrating said package, and bonding wires connecting said lead pins to said CCD chip. The CCD chip comprises an image pickup region for converting a ray incident thereto into an electric signal, and bonding pads in contact with said bonding wires and wherein said output face is in contact with said image pickup region and said output face is not in contact with said bonding pads.