Navigation device with consistent output and 2-stage moving average filter thereof
AssigneePixart Imaging Inc.
InventorsZi-Hao Tan, Kevin Len-Li Lim
Life of this patent
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Abstract
There is provided a 2-stage moving average filter for a navigation device including a delta regulator and an N-taps average circuit. The delta regulator is used as a first stage to receive motion delta at a varied frequency, and combine or split the received motion delta to output a regulated motion delta at a fixed frequency. The N-taps average circuit receives and averages N regulated motion delta and outputs the averaged motion delta at a fixed frequency.
Claims15
A navigation device, comprising:
- an image sensor configured to output image frames based on a dynamic frame period;
- a delta calculator configured to generate a motion delta at the dynamic frame period;
- a delta regulator configured to combine the calculated motion delta generated at the dynamic frame period when the dynamic frame period is smaller than a fixed period, and output the combined motion delta at the fixed period;
- an N-taps average circuit configured to receive the combined motion delta every fixed period for N times and average the N combined motion delta;
- an accumulator connected downstream of the N-taps average circuit, and configured to receive and accumulate the averaged motion delta before the accumulated motion delta is polled at a polling period that is an integer times of the fixed period, wherein the polling period is larger than the fixed period;
- and
- a bypass path, configured to bypass the delta regulator and directly connect the delta calculator to the N-taps average circuit when the dynamic frame period is equal to the fixed period.
A navigation device, comprising:
- an image sensor configured to output image frames based on a dynamic frame period;
- a delta calculator configured to generate a motion delta at the dynamic frame period;
- a delta regulator configured to split the calculated motion delta generated at the dynamic frame period when the dynamic frame period is larger than a fixed period, and output the split motion delta at the fixed period;
- an N-taps average circuit configured to receive the split motion delta every fixed period for N times and average the N split motion delta;
- an accumulator connected downstream of the N-taps average circuit, and configured to receive and accumulate the averaged motion delta before the accumulated motion delta is polled at a polling period that is an integer times of the fixed period, wherein the polling period is larger than the fixed period;
- and
- a bypass path, configured to bypass the delta regulator and directly connect the delta calculator to the N-taps average circuit when the dynamic frame period is equal to the fixed period.
A 2-stage moving average filter for a navigation device, the 2-stage moving average filter being configured to receive motion delta, and comprising:
- a delta regulator configured to receive the motion delta at a dynamic frame period and output a regulated motion delta at a fixed period;
- and
- an N-taps average circuit connected downstream of the delta regulator, and configured to receive the regulated motion delta every fixed period for N times and average the N regulated motion delta, wherein
- the averaged motion delta is configured to be accumulated by an accumulator of the navigation device before the accumulated motion delta is polled at a polling period that is an integer times of the fixed period, wherein the polling period is larger than the fixed period, and
- the motion delta is directly received by the N-taps average circuit to be averaged by bypassing the delta regulator with a bypass path when the dynamic frame period is equal to the fixed period.
Dependencies are inferred from the claim text.