Handheld article with movement discrimination
View Patent ↗A digital camera has a pair of angular rate-sensing gyroscopic sensors with mutually perpendicular axes and an electronic circuit responsive to the sensor output signals to discriminate between voluntary and involuntary movements of the article as a function of the number of zero crossings per unit time of the signal and the average of the absolute amplitude of the signal.
1. A handheld article having at least one angular rate-sensing gyroscopic sensor and an electronic circuit responsive to a sensor output signal to discriminate between voluntary and involuntary movements of the article as a function of the number of zero crossings per unit time of the signal and the average of the absolute amplitude of the signal, and wherein the function is proportional to the number of zero crossings of the signal and inversely proportional to the average of the absolute amplitude of the signal.
2. An article as claimed in claim 1 , including first and second angular rate-sensing gyroscopic sensors with transverse axes, the electronic circuit being responsive to both sensor output signals to discriminate between voluntary and involuntary movements of the article.
3. An article as claimed in claim 2 , wherein the axes of the first and second angular rate-sensing gyroscopic sensors are substantially perpendicular to one another.
4. A handheld article having first and second angular rate-sensing gyroscopic sensors with transverse axes that are substantially perpendicular to one another, and an electronic circuit responsive to sensor output signals, to discriminate between voluntary and involuntary movements of the article as a function of the number of zero crossings per unit time of the signal and the average of the absolute amplitude of the signal, wherein the electronic circuit discriminates between the voluntary and involuntary movements by determining whether the function
NZC 1 /|W| 1 +NZC 2 /|W| 2
exceeds a predetermined threshold, where NZC 1 and NZC 2 are the number of zero crossings per unit time for the output signals from the first and second sensors respectively, and |W| 1 and |W| 2 are the averages of the absolute amplitude of the output signals from the first and second sensors respectively.
5. An article as claimed in claim 1 or claim 4 , wherein the article is a digital camera.
6. An article as claimed in claim 5 wherein the camera is provided with image processing software responsive to said circuit indicating either voluntary and involuntary movement to control the processing of said image accordingly.
7. An article as claimed in claim 6 wherein said image processing software comprises face detection software which is operable in the absence of said circuit indicating voluntary movement.
8. An article as claimed in claim 6 wherein said image processing software comprises de-blur software which is operable in the absence of said circuit indicating voluntary movement.
9. An article as claimed in claim 3 or claim 4 , wherein the electronic circuit further discriminates between involuntary movements and sensor noise by determining whether the said function falls below a second predetermined threshold less than the first threshold.
10. An article as in claim 9 , wherein the function is proportional to the number of zero crossings of the signals and inversely proportional to the average of the absolute amplitude of the signals.