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US 4,698,496 AGranted
Image dissector tube with light filter
AssigneeU.S. Philips Corporation
InventorPierre Dolizy
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AssigneeU.S. Philips Corporation
InventorPierre Dolizy
Estimating the term…
Photoelectric detection device comprising a vacuum chamber provided with a window having a substrate which bears a photocathode on the internal surface of the vacuum chamber is sensitive to incident light radiation between a short wavelength .lambda..sub.1 bottom threshold and a longer wavelength .lambda..sub.2 upper threshold. Electrons emitted by the photocathode are focused, accelerated and deflected by electronic means to deliver signals or an image representative of luminous events projected onto the photocathode. Window is provided with at least one light filter which determines the wavelength range for which the detection device is operational, eliminating wavelengths greater than a wavelength .lambda..sub.f such that .lambda..sub.1 <.lambda..sub.f <.lambda..sub.2. This light filter can be a pass-band filter which also eliminates wavelengths lower than a wavelength .lambda.'.sub.f such that .lambda..sub.1 <.lambda.'.sub.f <.lambda..sub.f. This filter is preferably an interference filter, arranged on the outside and/or the inside of the vacuum chamber, constituted by a series of thin layers applied to the substrate. The invention has its principal application in image dissector tubes.
Photoelectric detection device comprising a vacuum chamber with a window formed by a substrate having an external surface outside the vacuum chamber and an internal surface inside the vacuum chamber, said substrate bearing a photocathode inside the vacuum chamber, the device being sensitive to incident light radiation between a short wavelength lower threshold .lambda..sub.1 and a longer wavelength upper threshold .lambda..sub.2, said thresholds defining the initial sensitivity range, the electrons emitted by the photocathode being focused, accelerated and deflected by electronic means to deliver signals or an image representative of luminous events projected onto the photocathode, characterized in that the window is provided with light filter means which eliminates wavelengths greater than a wavelength .lambda..sub.f in the initial sensitivity range, such that .lambda..sub.1 <.lambda..sub.f <.lambda..sub.2, where .lambda..sub.f is determined when the initial sensitivity of the detection device is a given percentage of its maximum initial sensitivity.
An image dissector tube comprising a vacuum chamber with a window formed by a substrate having an external surface outside the vacuum chamber and an internal surface directly on its internal surface, said substrate bearing a photocathode inside the vacuum chamber, the device being sensitive to incident light radiation between a short wavelength lower threshold .lambda..sub.1 and a longer wavelength upper threshold .lambda..sub.2, said thresholds defining the initial sensitivity range, the electrons emitted by the photocathode being focused, accelerated and deflected by electronic means to deliver signals or an image
Dependencies are inferred from the claim text.