Flat panel display drive circuit with switched drive current
First Claim
1. A field emission display having a level of brightness, the display comprising:
- a. a pixelator for field emission, the pixelator conducting a drive current, the drive current corresponding to the level of brightness;
b. a resistor for providing a resistance between the pixelator and a node and for establishing the drive current, the resistor having a first value; and
c. varying means for varying the resistance from the first value, the varying means enabled by a control signal, thereby varying the brightness in response to the control signal, wherein the varying means comprises;
(1) a second resistor having a second value; and
(2) a switch for connecting the resistor in parallel with the second resistor, the switch being enabled by the control signal.
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Accused Products
Abstract
A Field Emission Display ("FED") is disclosed having a brightness to project images. To achieve this benefit, the FED includes a pixelator which coupled to a display for displaying and projecting the image. By design, the pixelator conducts a drive current passing through the display grid corresponding to a degree of brightness in the resulting panel display. A first resistor having a first value is coupled between the pixelator and a voltage node or ground. Moreover, a second resistor having a second value at most one half of the first value is employed. A switch for connecting the first resistor in parallel with the second resistor is closed when a control signal is received when the switch is enabled, the equivalent resistance between the pixelator and a voltage node or ground is substantially reduced. In another embodiment, a tapped resistor replaces the first resistor and the second resistor. When the control signal is received, a portion of the drive current is shunted through the switch.
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Citations
22 Claims
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1. A field emission display having a level of brightness, the display comprising:
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a. a pixelator for field emission, the pixelator conducting a drive current, the drive current corresponding to the level of brightness; b. a resistor for providing a resistance between the pixelator and a node and for establishing the drive current, the resistor having a first value; and c. varying means for varying the resistance from the first value, the varying means enabled by a control signal, thereby varying the brightness in response to the control signal, wherein the varying means comprises; (1) a second resistor having a second value; and (2) a switch for connecting the resistor in parallel with the second resistor, the switch being enabled by the control signal. - View Dependent Claims (2)
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3. A field emission display having a brightness to project images, comprising:
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a display; a pixelator for driving said display, said pixelator conducting a current, said current corresponding to said brightness; a first resistor for providing a first resistance between said pixelator and a node, said first resistor having a first value; a second resistor having a second value, said second value comprising at most one half of said first value; and a switch for connecting said first resistor in parallel with said second resistor, said switch enabled by a control signal.
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4. A flat panel display having a pixel, the pixel having a brightness, pixel display enabled by a drive circuit, the drive circuit comprising:
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a. a first switch for selectively enabling pixel display by conducting a drive current through the first switch; b. a first resistor in series with the first switch for providing a first portion of the drive current, the first resistor comprising a tap; and c. a second switch, coupled to the tap, for shunting a portion of the first resistor in response to a control signal so that the brightness is responsive to the control signal. - View Dependent Claims (5, 6, 7)
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8. A flat panel display having a pixel, the pixel having a brightness, pixel display enabled by a drive circuit, the drive circuit comprising:
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a. a first switch for selectively enabling pixel display by conducting a drive current through the first switch; b. a first resistor in series with the first switch for providing a first portion of the drive current, the first resistor comprising a tap; and c. a current source coupled to the tap, the current source for providing, when selectively enabled by a control signal, a second portion of the drive current so that the brightness is responsive to the control signal.
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12. A flat panel display having a pixel, the pixel having a brightness, pixel display enabled by a drive circuit, the drive circuit comprising:
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a. a first switch for selectively enabling pixel display by conducting a drive current through the first switch; b. a first current source in series with the first switch for providing a first portion of the drive current; and c. a second current source coupled in parallel with the first current source, the second current source for providing, when selectively enabled by a control signal, a second portion of the drive current so that the brightness is responsive to the control signal. - View Dependent Claims (9, 10, 11, 13, 14, 15, 16, 17, 18, 19)
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20. A field emission display comprising:
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a. a first pixel having a first brightness, the first pixel enabled for display by a first switch, the first switch for selectively passing a first drive current; b. a second pixel having a second brightness the second pixel enabled for display by a second switch, the second switch for selectively passing a second drive current; c. a first current source coupled to the first switch and coupled to the second switch, the first current source for providing a first portion of both the first drive current and the second drive current; and d. a second current source coupled in parallel with the first current source, the second current source for providing, when selectively enabled by a control signal, a second portion of both the first drive current and the second drive current so that the first brightness and the second brightness are responsive to the control signal. - View Dependent Claims (21, 22)
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Specification