JPS646707B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an azimuth adaptive phased array sonar that can be applied to ultrasound imaging devices and the like.

In particular, the present invention relates to an azimuth adaptive phased array sonar that reduces the loss of a tapped delay circuit used in connection with a cross point switch.

[Description of prior art]

In conventional phased array sonar cross point switch settings, or delay mapping, the summing up line is set around the diagonal intersection of the cross point switch, as shown in Figure 3. .

In this setting method, signals are input and output through the delay circuit even when the deflection angle is 0°, so there are disadvantages such as loss caused by the delay time and problems such as multiple reflections and dispersion within the delay circuit.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an azimuth-adaptive phased array sonar that improves the drawbacks caused by delay mapping as described above, reduces the resulting loss, and improves image quality.

[Features of the invention]

The present invention aims to improve the image quality by improving the usage of a delay circuit with a tap connected to a cross point switch, and the present invention aims to improve image quality by improving the usage of a delay circuit with a tap connected to a cross point switch. and a transmitting/receiving device that obtains an image of an object by phase-driving the probe and scanning the transmitted and received ultrasonic beam in a fan shape. a cross point switch into which received output signals of the plurality of transducers coming from the transducers are input; and a delay circuit with taps into which signals from the numerous output terminals distributed by the cross point switch are respectively input. and a control circuit for controlling opening/closing of the cross point switch, wherein the control circuit is arranged so that a pattern in which the cross point switch is closed is set at the cross point. - Among the output terminals of the switch, the output terminals connected to the taps close to the output of the delay circuit are set so that the density of closed circuits is large, and the density of output terminals connected to taps far from the output is set to be closed circuits is small. It is characterized by:

Further, the delay circuit is preferably set so that the difference in delay time between adjacent taps is small in a portion close to the output of the delay circuit and large in a portion far from the output of the delay circuit.

[Explanation based on examples]

Hereinafter, the apparatus of the present invention will be explained in detail using the drawings.

FIG. 1 is a block diagram showing the configuration of the main parts of an apparatus according to an embodiment of the present invention. The output of the trigger generator 1 is connected to the input of the transmission delay map circuit 2a, and the output of the delay map circuit 2a is connected to the pulser 3. The output of the pulser 3 is coupled to each transducer 4 of the oscillator. Each transducer 4 of the probe is connected to the input of a receiving amplifier 5, and the output of the receiving amplifier 5 is connected to the input of a delay map circuit 2b for reception. The output of this delay map 2b is connected to the input of the signal processing circuit 6. The trigger generator 1 and both delay map circuits 2a, 2b are controlled by a controller 7. In the same figure, the delay map circuit 2a
2b and the controller 7 are parts related to the present invention.

In FIG. 1, a trigger generated from a trigger generator 1 under timing control by a controller 7 is applied to a transmission delay map circuit 2a. In the delay map circuit 2a, the same number of delay lines are prepared for the transducer 4, and the delay amount of each delay line is controlled by the controller 7, and the deflection angle of the transmitted and received beams is adjusted by taking beam focusing etc. into consideration. The delay time distribution is determined so that the angle is a predetermined angle. The delayed output obtained through such a delay map circuit 2a is given to the pulser 3. The pulsers 3 are individually directly connected to the transducers 4 which are energized at the same time, and are energized by the output of the delay line corresponding to each pulser 3 to generate transducer drive pulses and to drive each transducer. Excite user 4. As a result, an ultrasonic beam is projected from the transducer 4 in a determined direction.

After that, each echo signal received by each element of the transducer 4 and converted into an electric signal is amplified by a predetermined amplification factor in the receiving amplifier 5, and
Next, the echo signals are combined into a single signal after correcting the simultaneity of each echo signal via the reception delay map circuit 2b, which is set to have the same delay time distribution as the transmission delay map circuit 2a, and then guided to the signal processing circuit 6. . The signal processed by the signal processing circuit 6 is connected to a video signal output terminal.

FIG. 2 is a block configuration diagram showing the configuration of a delay map circuit according to the present invention. The delay map circuits 2a and 2b are the delay circuits 1 with taps.
1. It is composed of a terminal impedance 13 and a cross point switch 12, and the row direction terminal of the cross point switch 12 is connected to the pulser 3.
Alternatively, it is connected to the array transducer 4 via the receiving amplifier 5, and the terminal in the column direction is connected to the tap of the delay circuit 11 with a tap.
The connection setting of the intersections formed by the rows and columns of the cross point switches, ie, the delay mapping, is performed by commands from the controller 7.

3 and 4 show the state in which delay mapping is performed by the cross point switch 11 in FIG. 2. FIG. 3 shows the conventional setting method, and FIG. The setting method of the present invention is shown.

Here, when the summing up line is set to a certain deflection angle, among the intersections of the rows and columns of the cross point switch, the intersections on or near this summing up line are closed all at once, Of the external circuits connected to this cross point switch, the parts connected to this row and column are connected as a pair.

Now, the feature of the present invention is that, as shown in FIG. The delay mapping is performed to match the row of cross point switches connected to the tap closest to the output end of the delay circuit with taps, rather than the row on the position. Furthermore, one end of the summing up line to which an arbitrary deflection angle is mapped is located on the row of cross point switches corresponding to the deflection angle of 0°.

According to the present invention, it is possible to eliminate losses due to delay time near a deflection angle of 0°, and drawbacks due to multiple reflections and dispersion within the delay circuit. The adverse effect on the image caused by moving to one corner can be processed and removed on a back-up signal processing circuit.

Next, in order to make the effects of the present invention even more remarkable, the tap distribution of the delay circuit with taps is as shown in FIG. It can also be made coarser.

That is, it is known in FIG. 4 that the closer the summing up line is to the row of cross point switches corresponding to the deflection angle of 0°, the higher the distribution density of the summing up line is. Therefore, by shortening the delay times given to these columns, the average value of the delay times can be shortened.

The invention can be implemented on either the sending side or the receiving side, or both.

With this configuration, the signal loss generated in the delay map circuit is reduced, so
The gain of the amplifier connected after the delay map circuit can be reduced. Therefore, the circuit on the transmitting side can transmit a signal with less distortion, and the receiving side can obtain a signal with less noise.

〔Effect of the invention〕

The present invention achieves the following by devising the settings of the controller section and the tap distribution of the delay circuit with taps, without adding any hardware to the conventional device.
Among the delay times associated with phase drive, the delay time that has no effect on phase drive is removed, and the loss caused by the delay time and the negative effects of multiple reflections and dispersion occurring within the delay circuit are eliminated, thereby improving image quality. It has the effect of improving.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram showing the configuration of essential parts of an apparatus according to an embodiment of the present invention. FIG. 2 is a block configuration diagram showing the configuration of the delay map circuit. FIG. 3 is a diagram explaining conventional day mapping. FIG. 4 is a diagram illustrating day mapping according to the present invention. Fifth
The figure is a schematic diagram illustrating the connection relationship between the tapped delay circuit and the cross point switch of the present invention. 1...Trigger generator, 2a, 2b...Delay map circuit, 3...Pulser, 4...Array
Transducer, 5... Receiving amplifier, 6... Signal processing circuit, 7... Controller, 8... Video signal output terminal, 11... Delay circuit with tap, 1
2...Cross point switch, 13...Terminal impedance, 14...Summing up...
line.

Claims (1)

[Scope of Claims] 1. An array probe configured by arranging a plurality of transducers, and an array probe configured by arranging a plurality of transducers, and an ultrasonic beam that is transmitted and received by scanning the probe in a fan shape by driving the phase of the probe. a transmitting/receiving device for obtaining an image; a receiving section of the transmitting/receiving device includes a cross point switch for inputting received output signals of the plurality of transducers coming from the array probe; An azimuth angle adaptive phased array sonar comprising a delay circuit with a tap, which receives signals from a large number of output terminals distributed by a point switch as tap inputs, and a control circuit that controls opening and closing of the cross point switch. In this case, the control circuit has a pattern in which the closed circuit of the cross point switch has such a density that output terminals connected to taps close to the output of the delay circuit among the output terminals of the cross point switch are closed circuits. An azimuth adaptive phased array sonar characterized in that output terminals connected to taps that are far from the output are set so that the density of closed circuits is small. 2. The delay circuit is set such that the difference in delay time between adjacent taps is small in a portion close to the output of the delay circuit and large in a portion far from the output of the delay circuit. Azimuth adaptive phased array sonar as described in Section.