JP3088557B2 - Fish finder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fish finder which emits ultrasonic waves into water and displays the reflected signal on a CRT or the like to detect a fish school or the state of the sea bottom. More specifically, the present invention detects a sea bottom reflected signal. The present invention relates to a fish finder for displaying the bottom sediment state of the seabed.

[0002]

2. Description of the Related Art Conventionally, underwater acoustic equipment has been widely used for checking objects such as a school of fish existing under water, and a preferred example thereof is a fish finder. As is well known, a fish finder repeatedly emits a sound wave, particularly an ultrasonic pulse, into a predetermined range of water from a transducer including a single vibrating element or a plurality of appropriately arranged vibrating elements, and exists in the water. It receives a reflected signal reflected from an object or the sea floor or the like, and displays the state of the object or sediment on a display such as a CRT.

Next, the determination of the sediment state will be described. For example, as shown in FIG. 4A, when it is assumed that a reflected signal from the sea floor is received for a Tm time width after an ultrasonic wave is emitted, a display of a conventional fish finder is displayed. On the screen, Figure 4
As shown in (b), the seafloor reflection signal is displayed as a distance corresponding to the Tm time width. Time width T of seafloor reflection signal
m is determined by the seabed sediment. In general, when the seabed sediment is hard like a rock or a stone, the time width Tm is longer than usual, and when the sea sediment is soft like sand or mud, the time width Tm is larger than usual. It becomes shorter on the display, when the seabed is hard, and shorter when it is soft. In order to determine the bottom sediment state, it is determined from the change in the length of the seafloor reflection signal displayed on the display, but the depth of the seafloor was changed in order to always display the seafloor on the display screen. At times, the scale on the display is changed to always display the sea floor. In this case, the display length of the seafloor reflection signal also changes. As described above, since the display length of the seafloor reflection signal on the display changes depending on the change of the seafloor sediment and the change of the seafloor depth, the length of the seafloor reflection signal displayed on the display is reduced. In order to make an accurate determination, it is necessary to fully understand the correlation between the seabed sediment and the length of the seabed reflected signal displayed on the display, but this requires a long experience.

[0004]

As described above, the conventional fish finder has a problem that many years of experience are required to judge the seabed sediment. However, for example, in fishing trawls and nets using fishing nets, if the operation is performed without understanding the seabed sediment, the nets will be caught and damaged at rocky places, and catches may escape or the nets may be caught. They must be repaired, which wastes a great deal of effort and time and results in great losses. Therefore, in such an operation, it is indispensable to know the sea bottom sediment in advance by a fish finder.

The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a fish finder that allows anyone to grasp the bottom of the seabed without requiring any experience.

[0006]

A fish finder according to the present invention comprises: first measuring means for measuring an arrival time (T1) of a reflected signal after emitting a pulse signal each time an ultrasonic pulse is emitted; A second measuring means for measuring the time width (T2) of the arriving reflected signal; calculating T2 / T1; determining the seabed sediment by normalizing according to the water depth; and responding to the directional characteristics of the transducer.
And further comprising a display means for displaying weighted by a factor which defines Te, by the display means, the determined seabed sediment value edited by the display screen to a predetermined value or a predetermined seabed zone and wherein the benzalkonium be displayed in the corresponding graph.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention.
In the figure, 1 is a transmitting unit, 2 is a transducer, 3 is a receiving amplifier, 4 is an A / D converter, 5 is a fish finder buffer memory, 6 is a bottom sediment / fish finder memory, 7 is a comparator, and 8 is a first Counter,
9 is a second counter, 10 is a divider, 11 is a converter, 1
2 is a display control unit, 13 is an operation unit, 14 is a display unit, and 15 is a display.

Next, the operation of the fish finder shown in FIG. 1 will be described. The transmission unit 1 repeatedly generates a transmission signal that is a high-frequency electric signal having a constant pulse width, and transmits the transmission signal to the transducer 2. The transmitter / receiver 2 is generally installed on the bottom of the ship, is composed of, for example, an electrostrictive element, vibrates based on the transmitted transmission signal, and emits an ultrasonic pulse signal into water. The emitted ultrasonic pulse signal collides with a school of fish in the water or the sea floor and is reflected. The reflected signal is received by the electrostrictive element of the transducer 2, and the ultrasonic pulse signal is converted into a high-frequency electric signal and transmitted to the receiving amplifier 3. Sent and amplified.

The amplified reflected signal is sent to the A / D converter 4, converted into a digital signal corresponding to the strength of the reflected signal, and stored in the fish finder buffer memory 5. The fish finder buffer memory 5 has a capacity to store a digital signal corresponding to a reflected signal obtained by one transmission / reception,
The reflected signal obtained by one transmission / reception stored in the fish finder buffer memory 5 is read out as fish finder video data for one transmission and sent to the sediment / fish finder memory 6. Bottom material
The fish finder memory 6 has a capacity to store n pieces of fish finder video data for one transmission, and sequentially stores the transmitted fish finder video data. Then, when the storage area for n points prepared in the bottom sediment / fish finder memory 6 is filled, the oldest data, that is, the earliest transmitted fish finder video data is sequentially deleted.

Next, the organization of seabed sediment display data will be described. The reflected signal electrically amplified by the receiving amplifier 3 is also input to a comparator 7 where it is compared with a predetermined level LTH. Only a signal exceeding this LTH is output from the comparator 7 to the first level. Counter 8 and second counter 9
Output to The counter 8 measures the time from the emission of the ultrasonic wave to the detection of the reflected signal, and outputs the measured value (T1). The counter 9 measures the time width of the reflected signal exceeding LTH. And the measured value (T
Output 2).

FIG. 2 is a diagram for explaining the operation performed by the comparator 7 and the counters 8 and 9 described above.
2A shows the reflection signal input to the comparator 7 and a predetermined detection level LTH set in advance, and FIG. 2B shows the output of the comparator 7. In FIG. 2, 21 is a transmission signal, 22 is a submarine reflection signal, 23 is a comparator set level LTH <24 is an output value of the counter 8, 25 is an output value of the counter 9, 26 is a school of fish reflection signal, and t1 is a super-fish reflection signal. The time from the emission of the sound wave to the detection of the submarine reflected signal, t2 indicates the time width of the submarine reflected signal. The counter 8 measures t1 and outputs the measured value (T1). The counter 9 measures t2 and outputs the measured value (T2). The output values (T1) and (T2) of the counters 8 and 9 are input to the divider 10, and the divider 10 divides the measured value (T2) of the counter 9 by the measured value (T1) of the counter 8 to obtain T1 / T2. The operation is performed,
The time width of the seafloor reflection signal is normalized by the time from the emission of the ultrasonic wave to the detection of the seafloor signal to correct the change in the width of the seafloor reflection signal depending on the water depth, and is normalized and output by the water depth. Then, the output from the divider 10 is input to the converter 11 and is converted into a desired display output (for example, a sediment value weighted by a predetermined coefficient according to the directional characteristics of the transducer 2). Is sent to the sediment / fish finder memory 6.

The next display control unit 12 receives the information of the fish finder image display range set by the operator at the operation unit 13, calculates the reduction rate of the fish finder image display range on the CRT display screen, and calculates the sediment / fish finder. A preparation is made to display the sediment data and fish finder video data stored in the memory 6 on the CRT screen. That is, every time new data is stored in the sediment / fish finder memory 6, the latest fish finder video data for one transmission is read out by the display control unit 12, and the data is displayed in the depth direction for display in the fish finder video display range. Is appropriately reduced, for example, shallow depth data at the top and deep depth data at the bottom, and a fish finder image for one transmission in the vertical direction is converted into data having a different hue or brightness depending on the strength of the echo and displayed on the display unit. 14
At the same time, the sediment data stored in the sediment / fish finder memory 6 is read and sent to the display unit 14.

The display section 14 has a refresh memory for storing CRT screen information. The display section 14 converts output information from the display control section 12 into CRT screen information corresponding to the CRT of the display 15 and writes the CRT screen information into the refresh memory. At the same time, a video signal such as a fish finder image and a bottom quality value or a bottom quality graph read out from the refresh memory is transmitted in synchronization with the scanning of the display unit 15, and a desired image set by the operator on the operation unit 13 on the CRT. Is displayed.

FIG. 3 is a diagram showing a display example according to the present invention.
In the drawing, reference numeral 31 denotes a transmission line representing an ultrasonic emission signal, 3
2 is a seafloor reflection signal. Reference numeral 33 denotes a sediment value indicating the hardness of the seabed at the point where the ultrasonic pulse is currently emitted, 3
4 is a sediment curve showing a change in the hardness of the seabed in a certain range;
Reference numeral 35 denotes a depth scale, and although a conventional fish finder could obtain only information 31 and 32 as information, a bottom quality value of 33 and a bottom quality curve of 34 can also be obtained, which requires experience. Anyone can immediately judge the submarine sediment without having to do it.

In the above embodiment, two counters are provided. However, any configuration may be used as long as the means can measure the arrival time of the reflected signal and the time width of the reflected signal for each pulse. Further, the display is performed on a CRT, but the display method such as an LCD is not limited.

[0016]

As described above, the present invention can easily judge the sea bottom sediment from numerical values and graphs displayed on the display screen without requiring many years of experience, and can contribute to the safety and efficiency of operation. This has the effect.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a diagram for explaining a measurement principle of the present invention.

FIG. 3 is a diagram showing a display example of the present invention.

FIG. 4 is a diagram for explaining a detection method in a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmitting part 2 Transceiver 3 Amplifier 4 A / D converter 5 Fish finder buffer memory 6 Bottom material / fish finder memory 7 Comparator 8 First counter 9 Second counter 10 Divider 11 Converter 15 Display 33 Bottom material Value 34 Sediment curve

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-222852 (JP, A) JP-A-62-105075 (JP, A) JP-A-1-210886 (JP, A) 21794 (JP, U) Hikaru Hei 3-40583 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01S ⁷ /52-7/64 G01S 15/00-15/96

Claims (2)

(57) [Claims] A fish finder which emits an ultrasonic pulse signal into water, receives a reflected signal from a fish school or a seabed, and detects the presence of a school of fish or the bottom of the seabed. Measuring the time (T1) from the launching of the satellite to the arrival of the submarine reflection signal
Measuring means for measuring the time width (T2) of the arriving submarine reflection signal;
Measuring means performs a calculation of T2 / T1, normalized transducer by depth
A fish finder comprising display means for determining and displaying sea bottom sediment by weighting with a coefficient determined according to the directivity characteristics of the fish shoal. Wherein said the display unit, according to claim No. 1, characterized in the Turkey displays a graph corresponding to a predetermined value or a predetermined seabed area to edit and display screen a determined seabed sediment value Fish finder according to the item.