JPS5823905B2 - cathode ray tube display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a distance marker display device used for measuring the distance to a detected object displayed on a cathode ray tube, for example, in an underwater detection device that detects in a wide range of directions.

FIG. 1 shows an example of an underwater detection device that detects a wide range of directions underwater using ultrasonic pulses.

In the figure, a keying pulse generation circuit 1 generates keying pulses at regular intervals, and an ultrasonic pulse is transmitted from a transducer 2 using the keying pulses.

The transducer 2 is composed of a large number of ultrasonic transducers arranged in a circumferential manner, and all the transducers are simultaneously excited by a keying pulse to transmit ultrasonic pulses in a wide range of directions.

The reflected waves returning from the underwater detection object are received by the transducer 2.

At this time, the transducer/receiver 2 includes a large number of receiver assemblies in which a plurality of transducers are combined and each has a different composite directivity direction.

The reflected waves from each directional direction returning to each receiver structure are sent out in a time-division manner by the switching device 3.

On the other hand, the sine wave sent out from the sine wave generator 4 is transmitted to the modulator 5.
The signal is sent to the X-axis deflection circuit TX of the cathode ray tube 6 via.

Further, in conjunction with the sine wave generator 4, the cosine wave generator 8 generates a cosine wave, and this cosine wave passes through the modulator 9 and is transmitted to the cathode ray tube 6.
is sent to the Y-axis deflection circuit 7Y.

The modulators 5 and 9 are connected to the sine wave generator 4 and the cosine wave generator 8 by the sawtooth wave sent out from the sawtooth wave generator 10.
Modulates the amplitude of the sine and cosine waves sent out in a sawtooth pattern.

The electron beam of the cathode ray tube 6 is deflected by the modulated sine wave and cosine wave, resulting in a spiral sweep.

Further, at the same time as the spiral sweep is performed, the brightness of the electron beam is modulated by return signals from each direction sent out in a time-division manner from the switch 3 via the amplifier 11.

Therefore, if the sawtooth wave of the sawtooth wave generator 10 is synchronized with the keying pulse, and the switching operation of the switch 3 is performed in synchronization with the sine wave of the sine wave generator 4, the waves can be transmitted and received from each direction. The reflected waves returning to the device 2 are displayed on the cathode ray tube 6 in corresponding directions and distance positions, respectively.

As described above, while the detected object is being displayed, the sawtooth voltage of the sawtooth generator 10 is compared in the comparator circuit 12 with the set voltage of the setter 13.

The comparison circuit 12 sends out a luminance pulse to the luminance terminal of the cathode ray tube 6 when the sawtooth voltage and the set voltage match.

A circular bright line 14 is displayed on the cathode ray tube 6 by this brightness pulse.

This circular bright line 14 can be changed to any size by changing the setting voltage of the setting device 13.

Therefore, the bright line 14 can be used as a distance marker to measure the distance to the detected object.

That is, the set voltage of the setter 13 is adjusted to match the bright line 14 with the detected object on the cathode ray tube 6.

Then, the radius of the bright line 14 is determined from the set voltage at this time, and the distance to the detected object is measured based on the radius.

In the above, a distance marker (bright line 14) is displayed each time the sawtooth wave matches the set voltage.

Then, the sawtooth wave is sent out in accordance with the sending period of the keying pulse.

Furthermore, since the transducer 2 transmits the detection pulse using a keying pulse, the period of the keying pulse becomes longer as the detection distance becomes longer.

For example, when the detection distance is 1600 m, the period of the detection pulse is 2.1 seconds.

Therefore, at this time, the distance marker will also be displayed once every 2.1 seconds.

As a result, the number of times the distance marker is displayed is very small, and it is only displayed momentarily, making it very difficult to see ((
There is a drawback.

The present invention addresses the above-mentioned drawbacks and provides a device that can easily measure distances by displaying distance markers related to detection distance at relatively short intervals.

This will be explained below with reference to the embodiments shown in the drawings.

FIG. 2 shows an embodiment, in which the same numbers as in FIG. 1 perform the same operations.

In FIG. 2, the integrator 15 operates similarly to the sawtooth wave generator 10 in FIG. 1, and has a changeover switch Sw1.
Integrate the voltage of voltage setting 16 led through.

Then, when the keying pulse is sent out from the keying pulse generator 1, the integrated voltage of the integrator 15 is discharged.

Therefore, the integrator 15 receives the keying pulse (FIG. 3a)
The sawtooth wave shown in Fig. 3 is sent out in accordance with the period of .

The sawtooth waveform of the integrator 15 is sent to the modulation circuits 5 and 9 via the changeover switch SW2.

The modulation circuits 5 and 9 modulate the amplitudes of the sine wave and cosine wave of the sine wave generator 4 and the cosine wave generator 8 in a sawtooth manner in the same manner as shown in FIG. , sweeps the electron beam of the cathode ray tube 6 in a spiral manner.

Then, in the same manner as shown in FIG. 1, this spiral sweep wave is intensity-modulated by the reflected waves from each direction sent out in a time-division manner from the switching device 3, so that the detected object in each direction is displayed. 3. While the underwater detection signal is displayed as described above, the sine wave generator 4 sends out a pulse wave to the counting circuit 17 for each period of the sine wave.

The counting circuit 17 counts these pulse waves and sends out pulse waves C1, C2, and C3 (FIG. 3) to the output terminal PI + P2 rP3 every time a certain number of pulse waves are counted.

The sine wave generator 4 sends out a sine wave of several six periods in one period of the sawtooth wave.

Therefore, if the counting circuit 17 sends out output pulses C1+C2+C3 every ten pulse waves, the output pulses c and lc2+c3 correspond to one cycle of the sawtooth wave, that is, one display period of the detection signal. at least 10 within
Sent more than once.

The output pulse c11c2+c3 of the counting circuit 17 is set so that its pulse width matches one period of the sine wave or cosine wave of the sine wave generator 4 or the cosine wave generator 8.

Of the output pulses CI+C2tC3, pulse waves C1 and 03 are sent to the brightness erasing circuit 18, and brightness is erased while the pulse waves C1 and 03 are being sent.

Further, the pulse wave C2 is sent to the brightness terminal of the cathode ray tube 6, and bright line display is performed while the pulse wave C2 is being sent.

Therefore, while the pulse wave C2 is being sent out, the modulation circuit 5
A circular bright line 6M is displayed by the sine wave and cosine wave sent from the sine and cosine waves.

At this time, the size of the circular bright line 6M is determined by the changeover switch SW.
As a result, the output voltage of the DA conversion circuit 20 is sent to the modulation circuits 5 and 9, and is determined by this output voltage.

The DA converter 20 converts the output numerical value of the latch circuit 21 into an output voltage corresponding to the numerical value and sends it out.

Then, the latch circuit 21 stores the count value of the counting circuit 22 and sends it out.

The counting circuit 22 counts the pulse train of the clock pulse source 23, and the count value is reset every time the pulse wave C1 is sent out.

Further, the pulse wave C1 resets the counting circuit 22 and activates the monostable circuit 24 at the same time.

The monostable circuit 24 is activated for the TM waiting time as shown in FIG. 3d every time the pulse wave C1 is applied.

The activation time TM of the monostable circuit 24 can be changed arbitrarily.

The starting output d of the monostable circuit 24 is sent to the latch circuit 21, and the count value of the counting circuit 22 is stored in the latch circuit 21 when the starting output d falls.

Therefore, the latch circuit 21 stores a numerical value corresponding to the activation period TM of the monostable circuit 24.

As a result, the circular bright line 6M displayed on the cathode ray tube 6 is
Its size corresponds to the activation period TM of the monostable circuit 24.

Therefore, when the activation period TM of the monostable circuit 24 is adjusted to match the circular bright line 6M with the detected object displayed on the cathode ray tube, the activation period TM of the monostable circuit 24 is read.
The size of the circular bright line 6M, that is, the distance to the detected object can be known from the activation period TM.

During the activation period of the monostable circuit 24, the numerical value stored in the latch circuit 21 is displayed on the display 25, and the displayed value is displayed as the distance to the detected object.

In the above, the circular bright line 6M is displayed every time the pulse wave C2 is sent out.

The number of times the pulse wave C2 is displayed is determined by the number of times the pulse wave C2 is transmitted, regardless of the transmission cycle of the detection pulse of the transducer 2.

Therefore, in practice, the circular bright line 6M appears to be displayed almost continuously, and when this circular bright line 6M is used as a distance marker, it becomes very easy to measure the distance to the detected object.

In addition, in the above, the circular bright line 6 is created by the pulse wave C2.
M is displayed, and pulse waves C1 and C are displayed before and after pulse wave C2.
3 is sent out, but this is for the purpose of smoothly switching display between the circular bright line 6M and the display operation of the detected object.

That is, when performing a switching display, the electron beam must move from the display position of the detected object to the display position of the circular bright line.

During this moving period, the pulse waves C1 and C3 erase the brightness so that no bright line is displayed.

Furthermore, during the movement period of the electron beam and the display period of the circular bright line 6M, the pulse waves C1+C2 and C3 are sent from the OR circuit 26 to the changeover switch Sw1 so that the integrator 15 suspends the integration operation. .

The changeover switch SW1 stops the integration operation by switching the input voltage to the integrator 15 to the ground potential while the pulse waves C1+C2 and C3 are being sent out.

In FIG. 3, since the pulse waves C1 and C3 are used as brightness erasing pulses, they do not necessarily need to be set to one cycle of a sine wave or a cosine wave.

Deflection circuit 7X of cathode ray tube 6. When the response speed of 7Y is sufficiently fast, the pulse width may be shortened to, for example, a % period of a sine wave or a cosine wave.

[Brief explanation of the drawing]

FIG. 1 shows an example of a conventional device, FIG. 2 shows an embodiment of the present invention, and FIG. 3 shows a waveform diagram for explaining its operation.

Claims (1)

[Claims] 1. In a cathode ray tube display device that sweeps an electron beam in a spiral manner, the first sweep circuit causes the spiral sweep, the second sweep circuit causes the electron beam to perform a circular sweep, and the first sweep circuit A cathode ray tube display device comprising: a switching circuit that switches to circular sweep based on the second sweep circuit a plurality of times within one display period based on the above, and displays bright lines based on the circular sweep.