Detection chip capable of cancelling baseline voltage
AssigneePixart Imaging Inc.
InventorSung-Han Wu
Life of this patent
Estimating the term…
Abstract
There is provided a detection chip including a charging circuit, a discharging circuit, a counter and a processor. The charging circuit provides a first charging current within a first charging interval, and provides a second charging current, smaller than the first charging current, within a second charging interval. The discharging circuit provides a first discharging current within a first discharging interval, and provides a second discharging current, smaller than the first discharging current, within a second discharging interval. The counter counts the second charging interval and the second discharging interval. The processor identifies a touch event according to the second charging interval and the second discharging interval.
Claims20
A detection chip, configured to be electrically coupled to an electrode, the detection chip comprising:
- a charging circuit, configured to provide a first charging current within a first charging interval, and provide a second charging current, smaller than the first charging current, within a second charging interval;
- a discharging circuit, configured to provide a first discharging current within a first discharging interval, and provide a second discharging current, smaller than the first discharging current, within a second discharging interval;
- a counter, configured to sequentially count the first charging interval, the second charging interval, the first discharging interval and the second discharging interval as a detection cycle;
- and
- a processor, configured to identify a touch event according to the second charging interval and the second discharging interval without according to the first charging interval and the first discharging interval.
A detection chip, configured to be electrically coupled to an electrode, the detection chip comprising:
- a charging circuit, configured to provide a charging current within a charging interval;
- a discharging circuit, configured to provide a discharging current within a discharging interval;
- a counter, configured to sequentially count the charging interval and the discharging interval as a detection cycle;
- and
- a processor, configured to subtract a charging reference time and a discharging reference time from the detection cycle to obtain a time of interest, and output a control signal according to a variation of the time of interest between successive detection cycles.
A detection chip, configured to be electrically coupled to an electrode, the detection chip comprising:
- a charging circuit, configured to sequentially provide a first charging current and a second charging current, smaller than the first charging current, within a charging interval;
- a discharging circuit, configured to sequentially provide a first discharging current and a second discharging current, smaller than the first discharging current, within a discharging interval;
- and
- a processor, configured to
- exclude time intervals associated with the first charging current and the first discharging current from a summation of the charging interval and the discharging interval to determine a time of interest, and
- output a control signal by comparing the time of interest with a variation threshold.
Dependencies are inferred from the claim text.