Ultrasonic transmitter, ultrasonic transceiver and sounding apparatus

• US 7,372,775 B2
• Filed: 05/28/2004
• Issued: 05/13/2008
• Est. Priority Date: 05/29/2003
• Status: Active Grant

• Current Assignee: Furuno Electric Co, Ltd
• Original Assignee: Furuno Electric Co, Ltd
• Inventors: Hayashi, Tatsuo
• Primary Examiner(s): Lobo; Ian J.
• Application Number:
  US10/855,481
• Publication Number:
  US 20040240628A1
• Time in Patent Office: 1,446 Days
• Field of Search: 367/137, 367/138, 600/447
• US Class Current: 367/138
• CPC Class Codes: B06B 1/0238 of a single frequency, e.g. a sine-wave
• CPC Class Codes: B06B 1/0269 for generating multiple frequencies
• CPC Class Codes: B06B 2201/74 Underwater
• CPC Class Codes: G01S 7/521 Constructional features
• CPC Class Codes: G01S 7/524 Transmitters
• CPC Class Codes: G10K 11/346 using phase variation

Abstract

A driver circuit for generating a driving pulse signal to activate a vibrating element includes a half-bridge circuit formed essentially of first and second switching devices to which drive signals are supplied through a driver interface. A driving voltage is supplied to a source of the first switching device, a drain of the second switching device is grounded, and an output terminal of the half-bridge circuit is connected to the vibrating element. The half-bridge circuit is controlled such that the two switching devices alternately turn ON. When the first switching device is ON, the driving voltage is supplied as the driving pulse signal to the vibrating element, and when the second switching device is ON, the vibrating element and the second switching device together form a low-impedance closed loop. As the switching devices are caused to alternately turn ON at specific intervals, the vibrating element vibrates at a natural resonant frequency, transmitting thereby an ultrasonic signal.

Claims

1. An ultrasonic transmitter comprising:

a plurality of vibrating elements driven by specific pulse signals, the vibrating elements being arranged on the surface of a transducer; and

a transmitting beamformer for forming an ultrasonic transmitting beam by activating individual vibrating elements by feeding the pulse signals thereto, the transmitting beamformer including;

a bridge circuit including at least first and second switching devices connected in series between a ground potential and a driving voltage which determines the amplitude of each pulse signal, wherein the bridge circuit generates the pulse signal based on drive signals fed into the individual switching devices; and

a drive signal generator means for generating the drive signals to set the first and second switching devices of the bridge circuit ON and Off, the drive signal generator generating the drive signals to set the second switching device of the bridge circuit to an OFF state throughout a period when the first switching device of the bridge circuit is in an ON state, and forming a low impedance closed loop resonant circuit of the second switching device and the vibrating element by generating the drive signals to set the second switching device to the ON state throughout a period when the first switching device is in the OFF state.

2. An ultrasonic transceiver comprising:

the ultrasonic transmitter according to claim 1; and

a receiving beamformer for producing an ultrasonic receiving beam by controlling signals produced from ultrasonic waves received by a plurality of vibrating elements of the transducer.

3. A sounding apparatus comprising:

the ultrasonic transceiver according to claim 2; and

a device for controlling the receiving beamformer to scan successive azimuthal directions within the transmitting beam and pick up echo signals from the individual directions and for displaying detected echo data obtained from the echo signals.

4. The ultrasonic transmitter according to claim 1, wherein the bridge circuit further includes third and fourth switching devices connected in series and parallel to the first and second switching devices, the series connected third and fourth switching devices are also connected between the ground potential and the driving voltage, which determines the amplitude of each pulse signal, wherein the circuit generates the pulse signal based on the drive signals fed into the individual switching devices, and

wherein the drive signal generator means generates drive signals to set the second and third switching devices of the bridge circuit to an OFF state throughout a period when the first switching device of the bridge circuit is in an ON state, to set the first and fourth switching devices to the OFF state and the second switching device to the ON state throughout a period when the third switching device is in the ON state, and to set the second and fourth switching devices to the ON state throughout a period when both of the first and third switching devices are in the OFF state.

5. An ultrasonic transmitter comprising:

a vibrating element driven by a pulse signal; and

a bridge circuit including at least first and second switching devices connected in series between a ground potential and a driving voltage which determines the amplitude of the pulse signal, wherein the bridge circuit generates the pulse signal based on drive signals fed into the individual switching devices, with the pulse signal supplied to the vibrating element; and

a drive signal generator means for generating the drive signals to set the first and second switching devices of the bridge circuit ON and Off, the drive signal generator generating the drive sianals to set the second switching device of the bridge circuit to an OFF state throughout a period when the first switching device of the bridge circuit is in an ON state, and forming a low impedance closed loop resonant circuit of the second switching device and the vibrating element by generating the drive signals to set the second switching device to the ON state throughout a period when the first switching device is in the OFF state.

6. The ultrasonic transmitter according to claim 5, wherein the bridge circuit further includes third and fourth switching devices connected in senes and parallel to the first and second switching devices, the series connected third and fourth switching devices are also connected between the ground potential and the driving voltage, which determines the amplitude of each pulse signal, wherein the circuit generates the pulse signal based on the drive signals fed into the individual switching devices, and

the drive signal generator means generates drive signals to set the second and third switching devices of the bridge circuit to an OFF state throughout a period when the first switching device of the bridge circuit is in an ON state, to set the first and fourth switching devices to the OFF state and the second switching device to the ON state throughout a period when the third switching device is in the ON state, and to set the second and fourth switching devices to the ON state throughout a period when both of the first and third switching devices are in the OFF state.