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US 6,686,833 B2Granted
Compound acoustic actuator drive circuit and portable information terminal
AssigneeNEC Corporation
InventorChiemi Takahashi
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AssigneeNEC Corporation
InventorChiemi Takahashi
Estimating the term…
In a signal generation circuit for a compound acoustic actuator that generates a sound and a vibration in response to a frequency of a signal input to the compound acoustic actuator, the signal generation circuit comprising a plurality of signal data stored in a memory to generate a plurality of signals having mutually different frequencies, the plurality of signals at least including a signal, a frequency of which is equal to a resonant frequency causing the compound acoustic actuator to generate the vibration, a synthesizing means to synthesize a plurality of drive signals in accordance with the plurality of signal data so as to cause the compound acoustic actuator to generate the vibration, and a sweeping means to sweep the plurality of drive signals, repeatedly.
A signal generation circuit for a compound acoustic actuator that generates a sound and a vibration in response to a frequency of a signal input to said compound acoustic actuator, said signal generation circuit comprising:
A portable information terminal having a signal generation circuit for a compound acoustic actuator that generates a sound and a vibration in response to a frequency of a signal input to said compound acoustic actuator, said signal generation circuit comprising:
Dependencies are inferred from the claim text.
From the US filing history. Foreign family members aren’t listed.
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Term ended 10 Oct 2021 (estimated)
1. Field of the Invention
The present invention relates to a compound acoustic actuator drive circuit suitable for use in a portable information terminal having variations in the vibration resonant frequency of a compound acoustic actuator.
2. Related Art
FIG. 1(a) is a block diagram showing the configuration of the present invention.
FIG. 1(b) is a block diagram showing the PCM sound source circuit of the present invention.
FIG. 2 is a drawing illustrating the method of joining waveforms.
Embodiments of the present invention are described in detail below, with references made to relevant accompanying drawings.
(First Embodiment)
Specifically, FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. In the first embodiment, a signal generator 1 generates audible signal. At a PCM sound source (vibration signal generator) 4, a plurality of sine waveforms with a prescribed number of periods at prescribed frequency intervals are stored beforehand in a memory, and these are joined together and output. The signal generator 1 and the PCM sound source 4 form the drive signal circuit. An amplifier 2 amplifies the drive signal from the signal generator 1 and the PCM sound source 4, and output the amplified signal to a compound acoustic actuator 3. The compound acoustic actuator 3 generates a sound in accordance with the output from the signal generator 1 and generates a vibration based on the output from the PCM sound source 4.