JPS5937472B2 - Fish species identification fish finder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an improved fish species discriminating fish finder.

Conventionally, this type of fish finder displays the reflected signals of ultrasonic waves of multiple frequencies in different colors, and when two reflected signals are input at the same time, the one with the higher level is displayed. The reflected signal is displayed in color.

In general, low-frequency ultrasonic waves are difficult to reflect on schools of small fish, but they have the ability to reach deep seas, and high-frequency ultrasounds have the ability to reach only relatively shallow waters. It has the property of being highly reflective.

Therefore, conventional fish finders such as those described above use high and low frequency ultrasonic waves to display schools of large and small fish in relatively shallow waters and schools of large fish in relatively deep waters. However, it is said that it is not possible to distinguish and color-display schools of relatively shallow water that are a mix of large and small fish, or schools of relatively deep water that are a mix of large and medium-sized fish. There were drawbacks.

In order to eliminate the drawbacks of the conventional example, the present invention transmits a plurality of ultrasonic waves with different frequencies and collects the difference signal between two ultrasonic reflected waves with adjacent frequencies among the reflected waves. When two or more difference signals are input at the same time, a predetermined difference signal is prioritized and selected, thereby distinguishing and displaying schools of small and large fish. It provides an opportunity for

Hereinafter, the actual feeding will be explained in detail with reference to the drawings.

FIG. 1 shows one embodiment of the present invention, 1a*1
bslc and lct are transducers, 2a and 2b.

2c, 2d are transmitters, 3a, 3b, 3c, 3d are receivers, 4a, 4b, 4c are difference signal output circuits, 5 is a priority selection circuit, 6 is a color identification circuit, 7 is a storage device, 8 is a color C
It is an R tube.

Next, the operation of this embodiment will be explained with reference to FIG.

In general, high-frequency ultrasonic waves have short wavelengths, so they are reflected from even small schools of fish and have a large amount of attenuation, so they do not reach the deep sea.

Furthermore, because low-frequency ultrasound waves have long wavelengths, they are difficult to reflect from small objects, have less attenuation, and can reach deep seas.

Therefore, at the same depth, the relationship between the size of the fish and the reflected signal level due to the difference in frequency is as shown in Figure 2, and the relationship between the depth and the attenuation of the reflected signal level due to the difference in frequency is as shown in Figure 3. It will be as shown.

Next, the frequency of the ultrasonic waves output from the transceiver 1aslbsic*1d is set to 200)G (zs 5
0IG (z # 28KH2* 14KH2), and the reflected signals from the underwater bodies received by these transceivers 1a to 1d are amplified by each of the receivers 3a to 3d.
* When the output signal of 3b is input to the difference signal output circuit 4a and the output of the receiver 3b is subtracted from the output of the receiver 3a, the output signal of the difference signal output circuit 4a is a relatively shallow portion, and a small A reflected signal from a school of fish is output.

In addition, the output signals of the receivers 3b and 3c are output to a difference signal output circuit 4b.
K input and subtracting the output of the receiver 3c from the output of the receiver 3b, the output of the difference signal output circuit 4b is 5 in the slightly deeper part.
0 IG (Reflected signals are output only from schools of medium-sized fish that are well reflected by the ultrasonic waves of z.

Furthermore, when the output signals of the receivers 3c and 3d are input to the difference signal output circuit 4c and the output signal of the receiver 3d is subtracted from the output of the receiver 3c, the output signal of the difference signal output circuit 4C is a slightly deeper frequency of 28KHz. A difference signal output circuit 4a outputs reflected signals only from a school of slightly larger fish, from which the ultrasonic waves are well reflected.

The outputs of 4b and 4c are simultaneously input to the priority selection circuit 5.

This priority selection circuit 5 includes difference signal output circuits 4a, 4b, 4c.
When there are two or more inputs at the same time, only one output signal is selected.For example, if you want to highlight a school of small fish, give top priority to the output of the difference signal output circuit 4a. to select it and input it to the memory circuit 7.

If there is no output signal from the difference signal output circuit 4a, the output signal from the difference signal output circuit 4b is selected.

In this way, when the outputs of the difference signal output circuits 4a to 4c are selected, the outputs of these difference signal output circuits 4a to 4c are input to the color identification circuit 6 in order to identify which signal has been selected. The color of the selected output is determined and the signal is input to the memory circuit 7.

The signals are read out repeatedly from the memory circuit 7 in which the signals are stored in this way and are displayed on the color CR tube B trc.

In this embodiment configured as described above, for example, if a school of medium-sized or large-sized fish is mixed in a school of small-sized fish, the reflection signal of the small fish will be displayed with the medium-sized or large-sized fish. Since the reflected signal from the fish is inserted, it is possible to easily identify the parents of medium-sized or large-sized fish that are eating small fish.

In addition, the frequency of ultrasonic waves is 14 K) (z s 28 K)
Hz *1 50 KHz -200KHz,
This frequency can be chosen arbitrarily.

Moreover, although the low frequency is subtracted from the high frequency of the reflected signals of ultrasound waves of adjacent frequencies, it goes without saying that this may be reversed.

Furthermore, in the priority selection circuit, the signal of the difference between ultrasonic waves with a higher frequency is selected preferentially, but the signal of the difference between ultrasonic waves with a lower frequency may be given priority.

As explained above, according to the present invention, signals representing differences in reflected waves of ultrasound waves of adjacent frequencies are displayed in different colors, making it easy to distinguish between schools of fish with different fish bodies. It has the advantage of being

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention;
The figure shows the relationship between the size of the fish body and the reflected level of ultrasonic waves of different frequencies. Figure 3 shows the relationship between the depth and the attenuation of the reflected signal level due to the difference in frequency. be. 1a to 1d... Transducer/receiver, 2a to 2d...
...Transmitter, 3a-3d...Receiver, 4a-4
c... Difference signal; signal output circuit, 5... Priority selection circuit, 6... Color identification circuit, 7...
...Memory circuit, 8...Color CR tube.

Claims (1)

[Claims] 1 A plurality of transducers each transmit ultrasound waves of different frequencies and receive their reflected waves, and among the received reflected waves, the reflected waves of two ultrasound waves of adjacent frequencies are respectively inputted, and the difference signal is obtained. A plurality of difference signal output circuits that output a plurality of difference signals, a priority selection circuit that inputs the output difference signals and selects a predetermined difference signal with priority when two or more difference signals are input simultaneously, and each difference signal. 1. A fish finder for identifying fish species, comprising a color identification circuit that determines the color to be displayed for each color, and a display device that displays information on a selected difference signal in color.