Abstract: A buzzer assembly for a personal communications device changes geometry in order to emit sounds at a variety of frequencies at an approximately constant volume, such as for playing melodic alerts. The buzzer assembly incorporates a buzzer and gasket to create an air chamber with an associated acoustic impedance. A translational actuator moves a portion of either the buzzer or gasket, depending on the particular embodiment, to change the air volume and thus the associated acoustic impedance. By changing the acoustic impedance, the resonant frequency of the buzzer assembly is changed. When the buzzer is then operated at or near resonant frequency corresponding to the then-current acoustic impedance, the sound generated by the buzzer assembly is louder.

Abstract: A system for ink jet printing of messages on articles being fed forward one after another in a predetermined path. A terminal includes a keyboard for entering message data representative of the messages. A controller interconnected with the terminal processes the message data received from the terminal and stores the message data for the messages. The controller has an output port for providing serial output data in a bit map format representative of the messages. A plurality of ink jet printheads are serially connected and positioned adjacent the path of the articles to print the messages on the articles in response to the serial output data. A single cable connects the output port of the controller to the first printhead for providing the output data to the first printhead. A separate cable interconnects each printhead to its next succeeding printhead for serially providing the data to the remaining printheads so that the printheads are connected in a daisy chain configuration.

Abstract: A system for ink jet printing of messages on articles being fed forward one after another in a predetermined path. A terminal includes a keyboard for entering message data representative of the messages. A controller interconnected with the terminal processes the message data received from the terminal and stores the message data for the messages. The controller has an output port for providing serial output data in a bit map format representative of the messages. A plurality of ink jet printheads are serially connected and positioned adjacent the path of the articles to print the messages on the articles in response to the serial output data. A single cable connects the output port of the controller to the first printhead for providing the output data to the first printhead. A separate cable interconnects each printhead to its next succeeding printhead for serially providing the data to the remaining printheads so that the printheads are connected in a daisy chain configuration.

Abstract: In an audio system, a loudspeaker responds to an input signal producing a sound pressure wave having a linear component, which is linear function of the input signal, and an undesired non-linear component, which is a non-linear function of the input signal. Accordingly, it is desirable to reduce the non-linear component of the output sound pressure wave. An adaptive precompensating audio system for reducing this non-linear component includes a loudspeaker for producing a sound pressure wave and a precompensating filter for precompensating an input signal representative of the desired sound pressure wave. In addition, a microphone may be used to convert the resulting sound pressure wave into a sound signal and a precompensating filter modifier may be used to modify the precompensating filter in response to the sound signal. Preferably, the precompensating filter transforms the input signal using an inverse of an estimated transfer function for the loudspeaker.

Abstract: Central processing unit, responsive to the commands and print data signals, selectively stores the reference pattern signals from a pattern memory into a page memory. The central processing unit provides the first page pattern signal stored in the page memory to the laser printer engine for use in printing the first page while simultaneously providing the second page pattern signals from the pattern memory to the page memory to build the second page in the page memory. After the first page pattern signals have been provided to a laser printer engine, the central processing unit provides the second page pattern signals stored in the page memory to the laser printer engine for printing while simultaneously providing the subsequent page pattern signals from the pattern memory to the first page memory to build the subsequent page in the page memory. A bus interconnects the computer and the central processing unit, the pattern memory and the page memory and the page memory and the laser printer engine.