Abstract: Improved methods and apparatus for the removal of plaque from interproximal areas of the dental anatomy and from periodontal pockets. An reciprocal or orbital vibratory motion about the longitudinal axis of the bristles is utilized to impart frictional forces from a multitude of bristles positioned within the interproximal area of two adjacent teeth and in the periodontal pockets of the gum. An advanced embodiment utilizes ultrasonically enhanced bristle tufts to transmit ultrasonic vibrations into the gingival fluids in the periodontal pockets, producing standing ultrasonic waves within the gingival fluids which augments and enhances the plaque removal capability of the reciprocally or orbitally vibrating nylon bristles.

Abstract: An electronic system for the purpose of generating special effects in both color TV and color motion pictures is disclosed. A luminance key amplifier determines the average strength of matrixed red, blue and green video signals from a foreground camera and compares the average with a reference value. Areas of the foreground image that cause the average strength of the color signals to exceed the reference value, such as white, cause the luminance key system to key the green, blue and red signals from a background source such as a camera to an encoder, a video tape recording system or a film recording system. When the average strength of the red, blue and green signals from the foreground camera is less than the reference value, such as black or gray, the luminance key amplifier responds by passing the color signals from the foreground camera only to the encoder, video tape recording system or film recording system.

Abstract: A video traveling matte system is disclosed in which the video signal from a foreground television camera is examined for the presence of a particular color by an arrangement employing multipliers to multiply the differences between the red and blue components of the video signal and a luminance signal derived from the video signal by the signals from a sine/cosine potentiometer. The combined signal from the outputs of the multipliers is fed to a first comparator for comparison with a reference value, and the resulting pulses are filtered by a 4-pole active Bessel filter and compared with a reference value in a second comparator to increase the width of the pulses by a selected amount. The pulses of increased width prevent the formation of a matte outline between foreground and background images as the true and complementary values thereof are applied to alternately gate the video signals from the foreground television camera and a background television camera to a common output.