Apparatus and method for modulating a flat panel display device
AssigneeRCA Corporation
InventorJan Aleksander Rajchman
Life of this patent
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Abstract
A flat panel display device has a cathodoluminescent screen which is bombarded by a flow of electrons. The screen becomes electrically charged due to the electron bombardment. The charge striking various points on the screen is directly related to the image brightness at those points. The flow of electrons to each point is modulated by sensing the electrical charge which strikes the screen's surface at each point and comparing it to the image brightness signal for the display. When a predetermined relationship between the charge and the signal exists, indicating that the proper brightness level has been reached, the electron flow is terminated. The sensing system may be multiplexed to reduce its complexity.
Claims21
A system for modulating a display device having a cathodoluminescent screen comprising:
- means for sensing an electrical charge on the screen;
- and
- means for regulating the flow of electrons to the screen in response to the sensed charge.
An image display device having an envelope with a cathodoluminescent screen comprising:
- a plurality of electron multipliers within the envelope to establish a flow of electrons to the screen for the bombardment of a number of elements in a line of the image display;
- a plurality of M first electrodes for addressing specific elements in the line, X first electrodes being connected in common to form Y groups of first electrodes wherein M equals X times Y;
- a plurality of M second electrodes for modulating the electron flow to the screen, each of the second electrodes being associated with one of the first electrodes, Y second electrodes being connected in common to form X groups of second electrodes so that no group of first electrodes has more than one electrode associated with an electrode in each group of second electrodes and;
- a plurality of M anodes on the screen, Y anode electrodes being connected in common to form X groups of anode electrodes.
A method for modulating an image display device to control the image brightness, the display having a cathodoluminescent screen upon which an image is displayed, the method comprising:
- regulating the flow of electrons to the screen by sensing the electrical charge incident on the screen.
A method for modulating an image display device to control the image brightness, the device having a cathodoluminescent screen upon which an image is displayed, said method comprising regulating the flow of electrons by sensing the electrical potential between the screen and a reference point.
Dependencies are inferred from the claim text.