Digital display
View Patent ↗A display system that achieves a gamma characteristic different than 1, such as a gamma characteristic of 2 for example. The gamma characteristic may be selectable and it may be selectable via timing characteristics rather than by varying the intensity of the light source. Defective memory registers are also compensated for by selecting them to store bits of relatively lower significance.
1. A digital display, comprising:
an array of pixels arranged in rows and columns, each pixel having a selectable optical state; and
a plurality of pixel circuits, each pixel circuit associated with a pixel of the array of pixels, each pixel circuit including:
image data registers, the image data registers storing digital image data;
a logic circuit coupled to the image data registers, the logic circuit operable to select and read the digital image data from the image data registers and generate an output signal based on the digital image data and a digital logic signal; and
a pixel driver circuit that receives the output signal of the logic circuit and determines the optical state of the associated pixel based at least in part on the output signal;
wherein output nodes of the image data registers are coupled to a central node in the logic circuit through select switches, and wherein a plurality of the image data registers are selected in parallel, the output signal being dependent on a result of a function of digital image data of the plurality of selected image data registers and the digital logic signal.
2. A digital display as defined in claim 1 , wherein the image data registers in each pixel circuit include two banks of digital memory registers, and wherein each bank of digital memory registers stores a digital grayscale value for each component color for the associated pixel.
3. A digital display as defined in claim 2 , wherein each bank of digital memory registers stores an 8-bit digital grayscale value for each component color for the associated pixel.
4. A digital display as defined in claim 2 , wherein digital image data is routed to each bank of digital memory registers in each pixel circuit through local column data signals, wherein the local column data signals are local to each pixel circuit.
5. A digital display as defined in claim 1 , wherein the image data registers comprise dynamic memory registers.
6. A digital display as defined in claim 5 , wherein each pixel circuit includes sensing and refresh circuitry for each of the dynamic memory registers.
7. A digital display as defined in claim 1 , wherein the image data registers store image data as charge on FET transistor gates.
8. A digital display as defined in claim 1 , wherein the digital logic signal is coupled to and controls the select switches.
9. A digital display as defined in claim 1 , further comprising a column control circuit that drives a plurality of global column data signals, and wherein each pixel circuit includes a switch that selectably routes one of the plurality of global column data signals to a local column signal associated with the pixel group.
10. A digital display as defined in claim 1 , wherein the logic circuit reads a plurality of digital image data bits in parallel from the image data registers and the plurality of digital image data bits read by the logic circuit are used at the same time by the logic circuit to determine the output signal.
11. A digital display as defined in claim 10 , wherein the output of the logic circuit is dependent on a result of a wired-NOR function of the plurality of digital image data bits read in parallel and the digital logic signal.
12. A digital display as defined in claim 11 , wherein each pixel driver circuit selectably sets optical states of the pixels if the result of the wired-NOR function is a high logic state.
13. A digital display as defined in claim 1 , wherein the image data registers and the logic circuit of a pixel circuit are used to provide pulse width modulated drive waveforms between a plurality of optical states for each pixel of the array of pixels.
14. A digital display as defined in claim 13 , wherein a pixel electrode is driven to a first pixel voltage level at the beginning of a display phase for a component color and driven to a second pixel voltage level at a time dependent on a gray scale image data value for the component color stored in the image data registers.
15. A digital display, comprising:
an array of pixels in rows and columns, each pixel having a selectable optical state determined by a pixel driver circuit associated with the pixel;
image data registers that store digital image data for the array of pixels; and
a plurality of logic circuits that each select and read a plurality of the image data registers, the plurality of logic circuits each generating an output signal based on the selected plurality of image data registers and a digital logic signal;
wherein each logic circuit reads a plurality of digital image data bits in parallel from the image data registers and the plurality of digital image data bits read by the logic circuit are used at the same time by the logic circuit to determine the output signal, and wherein the output signal of the logic circuit is dependent on a result of a wired-NOR function of the plurality of digital image data bits read in parallel and the digital logic signal.
16. A digital display as defined in claim 15 , wherein the image data registers include two banks of digital memory registers, and wherein each bank of digital memory registers stores a digital grayscale value for each component color for the array of pixels.
17. A digital display as defined in claim 16 , wherein each bank of digital memory registers stores an 8-bit digital grayscale value for each component color for the array of pixels.
18. A digital display as defined in claim 16 , wherein digital image data is routed to each bank of digital memory registers through local column data signals, wherein the local column data signals are local to each pixel.
19. A digital display as defined in claim 15 , wherein the image data registers comprise dynamic memory registers.
20. A digital display as defined in claim 19 , wherein each pixel includes sensing and refresh circuitry for the dynamic memory registers.
21. A digital display as defined in claim 15 , wherein the image data registers store image data as charge on FET transistor gates.
22. A digital display as defined in claim 21 , wherein output nodes of the image data registers are coupled to a central node in the logic circuit through select switches.
23. A digital display as defined in claim 22 , wherein the digital logic signal is coupled to and controls the select switches.
24. A digital display as defined in claim 15 , further comprising a column control circuit that drives a plurality of global column data signals, and wherein each pixel includes a switch that selectably routes one of the plurality of global column data signals to a local column signal associated with the pixel.
25. A digital display as defined in claim 15 , wherein each pixel driver circuit selectably sets optical states of the pixels if the result of the wired-NOR function is a high logic state.
26. A digital display as defined in claim 15 , wherein the image data registers and the logic circuits are used to provide pulse width modulated drive waveforms between a plurality of optical states for each pixel of the array of pixels.
27. A digital display as defined in claim 26 , wherein a pixel electrode is driven to a first pixel voltage level at the beginning of a display phase for a component color and driven to a second pixel voltage level at a time dependent on a gray scale image data valve for the component color stored in the image data registers.