Abstract: An echo canceller device is provided with a first filter unit that generates a first output signal y1(k) by filtering a first input signal x1(k) with a filter coefficient h(k), an adaptation unit that modifies the filter coefficient h(k) on the basis of an adaptation algorithm so that a first error signal e1(k) becomes small, a first delaying unit that delays a first objective signal d1(k) by a certain time period ? and outputs the signal as a second objective signal d2(k), a second delaying unit that delays the first input signal x1(k) by the certain time period ? and outputs the signal as a second input signal x2(k), and a second filter unit that generates a second output signal y2(k) by filtering the second input signal x2(k) by the filter coefficient h(k) modified by the adaptation unit.

Abstract: An echo canceller device is provided with a first filter unit that generates a first output signal y1(k) by filtering a first input signal x1(k) with a filter coefficient h(k), an adaptation unit that modifies the filter coefficient h(k) on the basis of an adaptation algorithm so that a first error signal e1(k) becomes small, a first delaying unit that delays a first objective signal d1(k) by a certain time period ? and outputs the signal as a second objective signal d2(k), a second delaying unit that delays the first input signal x1(k) by the certain time period ? and outputs the signal as a second input signal x2(k), and a second filter unit that generates a second output signal y2(k) by filtering the second input signal x2(k) by the filter coefficient h(k) modified by the adaptation unit.

Abstract: The present invention relates to a switch device (100) for use in hand-held power tools. The switch device (100) may include at least one chamber (102) whose interior serves as an accommodation space. The chamber (102) may partially encase an operational member (104) for actuating the hand-held power tool through the switch device (100). Further, the switch device (100) is provided with multiple holes (202) on side walls (204) of the chamber (102) to create a passageway for external particulate materials. Also, a bottom surface (205) of the chamber (102) may be sloped to extend from an interior of the chamber (102) to each of the multiple holes (202), to enhance the discharging of the external particulate materials through the holes (202).

Abstract: The present invention relates to a switch device (100) for use in hand-held power tools. The switch device (100) may include at least one chamber (102) whose interior serves as an accommodation space. The chamber (102) may partially encase an operational member (104) for actuating the hand-held power tool through the switch device (100). Further, the switch device (100) is provided with multiple holes (202) on side walls (204) of the chamber (102) to create a passageway for external particulate materials. Also, a bottom surface (205) of the chamber (102) may be sloped to extend from an interior of the chamber (102) to each of the multiple holes (202), to enhance the discharging of the external particulate materials through the holes (202).