JPS5925031Y2 - Underwater detection recording device - Google Patents

Description

[Detailed explanation of the invention] This invention records underwater conditions by periodically emitting ultrasonic pulses into the water and applying reflected signals based on the detection pulses to a recording pen whose tip slides on recording paper. The present invention relates to an underwater detection recording device for drawing on paper, and particularly to an underwater detection recording device that can record even weak reflected signals without omission, regardless of the recording characteristics.

The case where this invention is applied to a fish finder using wet recording paper will be explained below.

It is well known that signals reflected from schools of fish are weaker than signals reflected from the seabed.

The fish finder operates as if it were to draw the underwater situation on a recording paper in shading, based on such weak reflection signals from the fish schools and strong reflection signals from the seabed.

The reflected signals from schools of fish are weak, so they are recorded faintly, and even if the reflected signals are of the same level, they may not be recorded if the wet recording paper is not sufficiently moist, or even if they are recorded, they may be too faint to be seen by the observer. I couldn't identify it.

Furthermore, the minimum value of the signal at which recording begins on the wet type recording paper differs from recording to recording, and this is particularly noticeable when the manufacturers are different.

This invention provides an underwater detection recording device that can record and display underwater conditions by effectively utilizing the dynamic range regardless of the wetness of the wet recording paper or even when using wet recording paper made by different manufacturers. The purpose is to

FIG. 1 shows an embodiment of this invention.

A wet type recording paper 1 is stretched between rollers 2 and 3 and is sequentially fed in the printing direction.

The recording pen 4 is suspended between a driving pulley 5 and an idler pulley 6, one end of which slides on the recording paper 1 as the belt rotates, and the other end of the recording pen 4 slides on a conductive plate 7. ing.

The transmitter 8 emits ultrasonic detection pulses into the water from the transducer 10 at a predetermined period in synchronization with the rotation of the belt 9, and also supplies them to the receiver 11.

A reflected signal from a school of fish, the seabed, etc. is supplied to one input terminal of an adder 12 via a receiver 11.

The adder 12 is configured by, for example, an operational amplifier.

The output signal of adder 12 is supplied to conductive plate 7 via gate 13 and OR circuit 14.

The output signal of the DC signal generator 15 is supplied to the other input terminal of the adder 12 and also to the gate 16 and the OR circuit 14.
It is supplied to the conductive plate 7 through.

The DC signal generator 15 first drives the selection circuit 17 to open the gate 16 and supplies the output signal to the rotating recording pen 4 via the conductive plate 7.

The DC signal generator 15 sends out a DC voltage signal whose value increases sequentially, stops increasing the DC voltage signal when recording on the recording paper 1 starts, and thereafter sends out a DC voltage signal that is held at that value. do.

The DC signal generator 15 is composed of, for example, a variable resistor and an electric motor that moves a movable piece of the variable resistor while sliding it on the resistor.
In this case, one end of the variable resistor is connected to a DC power supply and the other end is grounded, and a DC voltage signal is taken out from the movable piece moved by the motor and supplied to the other input terminal of the adder 12 and the gate 16.

The DC signal generator 15 detects a sudden increase in the current value supplied to the recording paper 1 via the gate 16 and stops the motor, thereby generating an output signal of the voltage value when recording on the recording paper starts. At the same time, the selection circuit 17 opens the gate 13.

Therefore, a composite signal obtained by adding the reflected signal to the DC voltage signal sent by the DC signal generator 15 is applied to the recording pen 4 via the gate 13, the OR circuit 14, and the conductive plate 7.

When the fish finder is started, the DC signal generator 15 causes the selection circuit 17 to open the gate 16, and outputs an output signal whose voltage value increases sequentially through the gate 16, the OR circuit 14, and the conductive plate 7 to record the rotation. Supply to pen 4.

When the recording pen 4 starts recording on the recording paper, the output current sent from the DC signal generator increases rapidly, and from this point on, the value of the DC voltage signal sent from the DC signal generator 15 is kept constant. It will be done.

At the same time, the gate 13 is opened by the selection circuit 17 while the gate 16 is closed, so that the recording pen 4 is supplied with a composite signal of the DC voltage signal sent by the DC signal generator 15 and the reflected signal.

Therefore, even weak reflected signals from schools of fish etc. are recorded without omission.

As mentioned above, this idea determines the minimum recording start voltage value for each recording paper used before actually operating the fish finder and applies it to the recording pen in advance, so it is possible to determine how weak the reflected signal is. Even if it is, recording is performed on the recording paper based on the reflected signal.

Therefore, it is possible to provide a recording device for an underwater detection device that can always record even weak signals without omission, regardless of the quality or wetness of the wet recording paper.

In the above embodiment, the case where wet type recording paper is used has been described, but this invention can be implemented in the same way when dry type recording paper is used.

In the above embodiment, a recording pen that is fixed to a belt and slides on the recording paper is used, but it is also possible to use a so-called multi-pen in which a large number of recording pens are arranged side by side in a direction perpendicular to the traveling direction of the recording paper. .

Note that the adder that adds the reflected signal and the DC setting value is not limited to the adder in the above embodiment, and the same effect can be obtained by using a transistor and a bias circuit provided on its base side. Obtainable.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of this invention.

Claims (1)

[Claim for Utility Model Registration] Ultrasonic detection pulses are periodically emitted into the water, and a composite signal obtained by adding the reflected signal based on the detection pulse and the minimum value DC signal that starts to be recorded on the recording paper is printed on the recording paper. In an underwater detection recording device that draws an underwater situation on a recording paper by applying it to a sliding recording pen, the DC signal generator supplies a DC signal whose value changes to the recording paper, and the reflected signal and the DC signal. An adder that adds the output signal of the generator, and a DC signal generator that automatically detects that it is supplying the minimum DC signal that starts recording on the recording paper and continues to generate this signal from then on. a controller for controlling the DC signal generator; and a selection circuit that selects the output signal of the DC signal generator or the adder and supplies it to recording paper. .