Abstract: The present invention demonstrates a method and a device in the technique of using an image sensing member, preferably a CCD cell instead of a film sensitive to X-ray radiation. The method and the device is applicable to a general X-ray arrangement without any necessary direct connection between the image sensing member and the X-ray arrangement. A number of detector points for X-ray radiation are provided at or in the CCD cell. The method and device of the present invention result in minimizing of the radiation dose to exactly that which is needed for exact imaging exposure of an image, and therefore more images may be obtained within the same total normal radiation dose.

Abstract: A method and a device for compensating dark currents of a CCD sensor in dental imaging utilizes a compensation signal to guarantee that picture elements within faintly exposed image areas in dental x-raying will be located within a desired signal level interval, which, on a video monitor, corresponds to a light intensity which would have been obtained had a dental x-ray film been used. In this manner, a maximum imaging sensitivity for gray level variations is obtained, thereby facilitating the imaging of enamel and dentine in dental x-raying. The strong dependence of the dark current upon ambient temperature is compensated by a signal processing device upon generation of raw data to achieve a maximum possible image quality and resolution. The imaging of enamel and dentine is facilitated by this dark current compensation and by a non-linear digitalization of the output of the image sensor.