Image pick-up device
AssigneeU.S. Philips Corporation
InventorGijsbertus Bouwhuis
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Abstract
An image pick-up device with an electronic image sensor (IS.sub.1 IS.sub.2) is described, which includes a matrix of sensor elements (SE) and a low-pass filter for suppressing image frequencies exceeding the sampling frequency of the sensor. The low-pass filter has a first, composite filter function (F.sub.com) consisting of a variable component and a constant component and the device has a second filter function (F.sub.c) in conformity with the constant component which is optically or electronically subtracted from the first filter function.
Claims7
An image pick-up device comprising an imaging lens system, an optical radiation-sensitive detection system having discrete detection elements arranged in a periodic pattern with a given period, and low-pass filter means for suppressing image frequencies which exceed the spatial frequency of the detection system, characterized in that the low-pass filter means comprises, for each image-information transporting channel:
- first filter means constituted by an optical filter having a filter function composed of a required variable component and an additional constant function forming a composite filter function;
- and
- second filter means having a filter function corresponding to said additional constant function, wherein the combination of said first and second filter means constitutes said low-pass filter means and provides the required variable filter function whereby the filter function of said second filter means is subtracted from the filter function of said first filter means thereby cancelling said additional constant functions and leaving said required variable filter function.
Dependencies are inferred from the claim text.