| 摘要 |
PURPOSE:To derive exactly a tracking point of a target by erasing effectively a pseudo light source, and executing a comparatively simple picture processing. CONSTITUTION:An infrared radiation from a target and a pseudo light source of the sun, etc. is made to form an image by an image forming optical system 1, and it is demultiplexed by a dichroic mirror 8. An infrared image of a near infrared light whose wavelength is about 1-2.5mum and a middle infrared light whose wavelength is about 3-4.5mum is brought to an image pickup to infrared solid image pickup elements 9a, 9b. In this case, there is a difference in a spectrum distribution of an infrared radiation emitted by the target and the pseudo light source, therefore, in the target picture element, an output 3a (level A) of an amplifier 10a is always smaller than an output 3b (level B) of an amplifier 10b, and in the pseudo light source picture element, it becomes opposite. Accordingly, the target picture element is discriminated by A/B by a discriminator 11, it is binary-coded, and a binary-coded signal 5 is outputted. Only the target picture element appears in the signal 5, and the pseudo light source is erased, therefore, a centroid point coordinate of only the target picture element is obtained in a centroid point operating circuit 6. |
