Foveated display
An electronic device such as a head-mounted device may have displays. The display may have regions of lower (L) and higher (M, H) resolution to reduce data bandwidth and power consumption for the display while preserving satisfactory image quality. Data lines may be shared by lower and higher resolution portions of a display or different portions of a display with different resolutions may be supplied with different numbers of data lines. Data line length may be varied in transition regions between lower resolution and higher resolution portions of a display to reduce visible discontinuities between the lower and higher resolution portions. The lower and higher resolution portions of the display may be dynamically adjusted using dynamically adjustable gate driver circuitry and dynamically adjustable data line driver circuitry.
1. An electronic device, comprising:
at least one lens;
an array of pixels configured to produce light that passes through the lens;
data lines;
data line driver circuitry configured to supply data signals to the pixels over the data lines with a dynamically adjustable resolution;
gate lines coupled to the pixels; and
gate line driver circuitry comprising a shift register formed from a chain of gate blocks, wherein each gate block is configured to receive a respective resolution mode control signal, and wherein each gate block is configured to supply output signals to the gate lines with a resolution that is based on the respective resolution mode control signal.
2. The electronic device defined in claim 1 wherein each respective resolution mode control signal comprises a two-bit control signal and wherein the gate blocks are configured to operate in at least first, second, and third modes.
3. The electronic device defined in claim 2 wherein each gate block includes at least first, second, third, and fourth outputs and wherein each gate block is configured to:
assert pulses on the first, second, third, and fourth outputs simultaneously in the first mode in response to receipt of a clock signal.
4. The electronic device defined in claim 3 wherein in the second mode each gate block is further configured to:
assert pulses on the first and second outputs simultaneously in response to receipt of a first clock signal; and
assert pulses on the third and fourth outputs simultaneously in response to receipt of a second clock signal that is different than the first clock signal.
5. The electronic device defined in claim 4 wherein in the third mode each gate block is further configured to:
assert a pulse on the first output in response to receipt of a first clock signal;
assert a pulse on the second output in response to receipt of a second clock signal that is different than the first clock signal;
assert a pulse on the third output in response to receipt of a third clock signal that is different than the first and second clock signals; and
assert a pulse on the fourth output in response to receipt of a fourth clock signal that is different than the first, second, and third clock signals.
6. The electronic device defined in claim 1 wherein the data line driver circuitry includes an adjustable shift register.
7. The electronic device defined in claim 6 wherein the adjustable shift register includes a plurality of shift register blocks each of which includes at least first, second, third, and fourth registers.
8. The electronic device defined in claim 7 wherein each of the shift register blocks is configured to operate in at least first, second, and third modes and wherein in the first mode data is loaded into the first, second, third, and fourth registers in parallel.
9. The electronic device defined in claim 8 wherein in the second mode data is loaded into the first and second registers in parallel on a first clock cycle and is shifted from the first and second registers into the third and fourth registers on a second clock cycle that is different than the first clock cycle and wherein in the third mode data is loaded into the first, second, third, and fourth registers on separate clock cycles.
10. An electronic device, comprising:
at least one lens; and
a display, wherein the display comprises:
an array of pixels configured to produce light that passes through the lens;
data lines;
data line driver circuitry configured to supply data signals to the pixels over the data lines with a dynamically adjustable resolution;
gate lines coupled to the pixels; and
gate line driver circuitry comprising a plurality of gate blocks, wherein each gate block is configured to receive a resolution mode control signal and supply gate line signals to the pixels over the gate lines with a dynamically adjustable resolution based on the resolution mode control signal, wherein each gate block has a plurality of outputs, and wherein each gate block asserts pulses on the plurality of outputs based on the resolution mode control signal.
11. The electronic device defined in claim 10 wherein the data line driver circuitry includes an adjustable shift register.
12. The electronic device defined in claim 11 wherein the adjustable shift register includes a plurality of shift register blocks each of which includes at least first, second, third, and fourth registers.
13. The electronic device defined in claim 12 wherein each of the shift register blocks is configured to operate in at least first, second, and third modes, wherein in the first mode data is loaded into the first, second, third, and fourth registers in parallel, wherein in the second mode data is loaded into the first and second registers in parallel on a first clock cycle and is shifted from the first and second registers into the third and fourth registers on a second clock cycle that is different than the first clock cycle, and wherein in the third mode data is loaded into the first, second, third, and fourth registers on separate clock cycles.
14. The electronic device defined in claim 10 , wherein the gate blocks are configured to operate in one of a first, second, and third mode based on the resolution mode control signal and wherein each one of the first, second, and third modes is associated with a unique respective timing scheme for asserting pulses on the plurality of outputs.
15. An electronic device, comprising:
at least one lens; and
a display, wherein the display comprises:
an array of pixels configured to produce light that passes through the lens;
data lines;
data line driver circuitry configured to supply data signals to the pixels over the data lines with a dynamically adjustable resolution;
gate lines coupled to the pixels; and
gate line driver circuitry configured to supply gate line signals to the pixels over the gate lines with a dynamically adjustable resolution, wherein the gate line driver circuitry includes a plurality of gate blocks each of which receives a two-bit resolution mode control signal and wherein the gate blocks are configured to operate in at least first, second, and third modes, wherein each gate block includes at least first, second, third, and fourth outputs, and wherein each gate block is configured to assert pulses on the first, second, third, and fourth outputs at different times in the first, second, and third modes.
16. The electronic device defined in claim 15 wherein each gate block is configured to:
assert pulses on the first, second, third, and fourth outputs simultaneously in the first mode in response to receipt of a clock signal.
17. The electronic device defined in claim 16 wherein in the second mode each gate block is further configured to:
assert pulses on the first and second outputs simultaneously in response to receipt of a first clock signal; and
assert pulses on the third and fourth outputs simultaneously in response to receipt of a second clock signal that is different than the first clock signal.
18. The electronic device defined in claim 17 wherein in the third mode each gate block is further configured to:
assert a pulse on the first output in response to receipt of a first clock signal;
assert a pulse on the second output in response to receipt of a second clock signal that is different than the first clock signal;
assert a pulse on the third output in response to receipt of a third clock signal that is different than the first and second clock signals; and
assert a pulse on the fourth output in response to receipt of a fourth clock signal that is different than the first, second, and third clock signals.