Compaq Computer Corporation, Inc.

Hewlett-packard Development Company, L.P.

Compaq Information Technologies Group, L.p.

Mitchell A Markow

David E Gough

Jeremy M Ford

Ji-An Gong

Michael S Lempicki

Dennis D Lamberth

Steven S Homer

Kelly Kennedy Smith

Rabah S Hamdi

Steve S Homer

Stephen K Gustafson

A desktop computer which has a driver mounted in the back wall of the chassis. The chassis is acoustically a very leaky box, so the driver is designed as if it were a free-space driver (using large cone area and long throw). In one class of embodiments, a single driver is used, and is centered in the back of the box so that there is an equal left-right split, although not true stereo. The front of the box may be made more acoustically leaky to move the acoustic image forward. The treatment of the box as being acoustically leaky means that the airflow required for thermal management has not been restricted. The use of a long-throw driver permits the volume-velocity of the driver to be increased. Treatment of the box as very leaky also means that no user changes or custom configurations will significantly disturb the expected acoustic environment. An audio system incorporating a free-space driver with an equalizer designed for use with a free-space driver further improves acoustic quality. Gain staging may also be used to improve acoustic quality of the audio system.

Computer with acoustic driver built into acoustically leaky chassis

A portable electronic device having a rigid chassis. The portable electronic device utilizes a reinforcement structure within the chassis. The structure is designed for application in a space constrained area by incorporating one or more speaker mounts and speakers for audio output.

Portable electronic device having chassis reinforcement system

Custom designed polar patterns for a microphone of a portable computer are achieved. A custom designed polar pattern permits a microphone in a portable computer to suppress sources of spatially-dependent noise internal and external to a portable computer system. A custom designed polar pattern is generated by specially configuring the boot of a microphone by varying the hole sizes of the boot and/or varying location of the microphone element in the boot. In addition, the shape of a particular polar pattern may be adjusted by inserting acoustic absorption material into the boot, forming enclosed walls into the boot, or rotating the top shell of the portable computer which contains the microphone relative to the bottom shell of the portable computer. Thus, a directional response of a microphone may be form-fitted to a particular portable computer configuration.

Method of custom designing directional responses for a microphone of a portable computer

A speakerphone of a system with a digital signal processor, such as a computer, uses a filter set or network to provide acoustic coupling loss at a microphone to offset acoustic coupling gain produced by sound reflections resulting from various conditions in the system. The filter network processes an acoustic signal before the signal is provided to a digital signal processor to eliminate acoustic coupling gain that the digital signal processor is unable to cancel or offset. The filter network detects when the acoustic coupling gain in the acoustic signal at the microphone exceeds the maximum amount of acoustic coupling loss supplied by the digital signal processor. Alternatively, if acoustic coupling gain is desirable at the frequency location of the anomaly caused by the sound reflections, the filter network is used to boost the acoustic coupling gain produced by the anomaly. Thus, the present speakerphone uses equalization at the microphone to boost or attenuate acoustic coupling gain caused by frequency anomalies before acoustic echo cancellation by the digital signal processor.

Acoustic coupling compensation for a speakerphone of a system

An expansion base with a rearward-emitting expansion speaker for emitting low frequency audio and providing surround sound capability. The frequency response of the expansion speaker includes subwoofer frequencies, and is also extended to 600 Hz or higher, to enhance surround sound and spatial impression effects.

Portable computer expansion base with enhancement speaker

A high voltage flyback power supply provides slope-based primary feedback to control the off-time of the power supply. When a negative slope is detected at a low side of a primary winding of the power supply, an off-time cycle is terminated and a next on-time cycle is initiated. The slope-based off-time primary feedback helps to keep the off-time of the power supply in sync with ringing of the primary leakage inductance and the primary-side capacitance of the power supply. Such a power supply is particularly useful for battery-powered systems with low voltage rails. The power supply can also include on-time feedback to shorten the on-time of the power supply after the secondary-side voltage rises beyond a certain relatively high voltage level. In this way, the transformer of the power supply is charged less when the power supply is driving relatively light loads.

Slope-based primary feedback to control the off-time of a power supply

A method for improving spatial impression in a four-speaker system using dynamic and piezo transducers. The use of a piezo transducer eliminates the need for a low-pass filter.

Portable computer with both dynamic and piezoelectric transducers

A method and apparatus for controlling acoustic gain during a non-speakerphone audio mode of computer system independent of acoustic gain during a speakerphone mode of the computer system is provided. The BIOS code of the computer system detects whether the computer system is in a speakerphone mode or a non-speakerphone audio mode. If the computer system is in a speakerphone mode, an upper gain limit is not applied to the microphone path of the computer system. If the computer system is in a non-speakerphone audio mode, a predetermined upper gain limit is applied to the microphone path of the computer system. The predetermined upper gain limit is preferably applied to the microphone path at either a microphone pre-amplifier or an audio mixer chip in the microphone path of the computer system.

Method and apparatus for independent gain control of a microphone and speaker for a speakerphone mode and a non-speakerphone audio mode of a computer system

A stereo speaker system for portable computers which maximizes spatial impression by using rearward-firing speakers, mounted in the back of the display, in combination with forward-firing speakers mounted on the chassis or in the front side of the display.

Onboard speaker system for portable computers which maximizes broad spatial impression

Piezoelectric speaker achieves radiation efficiency at low frequencies by using a piezoelectric speaker panel as a lumped parameter resonator. The speaker panel is mounted in a resonant system for generating translational motion. The resonant system includes suspension devices for suspending the panel to allow for translational motion of the panel and isolators for tuning the speaker panel to a predetermined frequency. At the predetermined frequency, the speaker panel achieves resonance in a low order mode, producing improved radiation efficiency at lower frequencies and translational motion of the panel not possible with a piezoelectric activator alone. The speaker panel may be included in a portable computer system, a desktop computer monitor, or other sound systems. In a portable computer system, a display screen or front speaker panel serves as a lumped parameter resonator, and the lid or rear speaker panel serves as a structure born vibration resonator. The front speaker panel may be driven or excited by coupling a piezoelectric actuator or a plurality of actuators to the front speaker panel, the rear speaker panel, or both panels. When the piezoelectric actuator is coupled to the rear speaker panel, a connection between the panels transfers the vibration energy to the front speaker panel. Further, the actuator or actuators used may be placed at suitable locations on one or both panels.

Lumped parameter resonator of a piezoelectric speaker

A portable computer system having a loudspeaker enclosure defined by a printed circuit board, a keyboard section cover and a gasket. A second enclosure is defined by an existing frame, the keyboard section cover and a second gasket. Advantageously, a loudspeaker mounting system provides positive urging of the speaker with the keyboard section cover and all other openings, such as the grill attachment apertures and any other openings, are sealed to achieve the total enclosure concept for a speaker system for a portable computer.

Portable computer having loudspeakers in enclosures formed by gaskets

A signal processing apparatus for processing data digital signals is disclosed. The signal processing apparatus includes a high-efficiency power switching amplifier that optimizes processing during low-power applications. A signal equalizer is further coupled to the power switching amplifier and has a plurality of signal bands for defining equalization characteristic desired for the signal processing system. A gain control unit is coupled to the signal equalizer for adjusting gain of the equalized input signal handled by the signal equalizer. Lastly, a digital amplitude compressor is coupled to the gain controller and the power switching amplifier and is programmable so as to compress only those signals having an amplitude greater than a first threshold level without compressing those signals that fall below that first threshold level. Typically, low-power applications cover wattage ranging from two to seven watts of power.

Signal processing apparatus with selective power amplification

A laptop computer is disclosed that includes an improved audio speaker system. The laptop computer typically is designed to have a first shell and a second shell that are attached together. Typically located within the first shell are a central processing unit, a keyboard, and other circuits such as a battery, a hard disk storage, and other connectors such as a PCMCIA slot. A video monitor is typically located in the second shell of the laptop computer and is coupled to the central processing unit via a system bust, or a video driver is provided that may be subsequently coupled to the CPU, such that the video driver drives the video monitor. Then, an audio speaker system is provided that in one embodiment is mounted in a back portion of the second shell that is located opposite the video monitor. This audio speaker system includes a transmission line comprising a first piezo speaker and a second piezo speaker. The transmission line is set at such a distance so that the first piezo speaker can cover a selected range of frequencies while the second piezo speaker is set at a second distance in such a manner as to skew the frequency response between the first piezo speaker and the second piezo speaker, thereby providing frequency overlap to occur between the two speakers.

Multiple channel speaker system for a portable computer

A portable computer docking station has a molded plastic housing within the interior of which are a ported speaker structure operative at low, mid and high frequencies, and a nonported speaker structure operative only at mid-to-high frequencies. The ported speaker structure has a ported enclosure section formed integrally with an exterior wall portion of the housing and having an open side. A first speaker is mounted on a lid member at an opening therein, with the lid member being secured to the ported enclosure section over the open side thereof with a seal member being sandwiched between the lid member and the enclosure section, and a sound absorbing structure being disposed within the enclosure section under the first speaker. The nonported speaker structure includes a second speaker supported on a second wall portion of the housing. A mid-range enclosure, formed from an open cell foam material, engages a section of the second wall portion that circumscribes the second speaker and has a chamber therein that receives the second speaker. The input of the first speaker is connected to the output of a first amplifier having an input in turn connected to a first equalizing circuit. The input of the second speaker is connected to the output of a second amplifier, having a wattage capacity less than that of the first amplifier. A second equalizing circuit is connected to the input of the second amplifier.

Portable computer docking station having improved speaker apparatus

A speaker system for use in a thin film video monitor apparatus is disclosed. The video monitor apparatus includes a thin film video display panel as well as a stiffening panel adjacent to the thin film video display panel. Next, a plurality of piezo speaker transducers are attached to one of the sides of the stiffening panel. The stiffening panel typically is composed of a material such as aluminum honeycomb sheets or a polycarbonate sheet. Other materials for use as the stiffener may include magnesium shells or ABS plastic. The speakers are defined so that a first sound channel and a second sound channel are provided, and these sound channels can define a left and right channel for proper stereo imaging. Between the video monitor and the stiffening panel is located an electromagnetic interference (EMI) shield. Further, a transmission line is provided to connect a first piezo transducer to a second piezo transducer in such a way so that frequency overlap can occur between the two transducers based upon the transmission line distance defined for the first piezo transducer and for the second piezo transducer. Further, the transmission line may have the same distance between both speakers where frequency overlap is not a concern. The stiffening panel is provided to increase the mobile energy in the lower frequencies during operation.

Growing community of inventors

Spring, TX, United States of America

Mitchell A Markow