JP2001174546A - Distance detecting display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distance detecting display device capable of comparatively detecting and displaying the intensity change of a reflected signal of a detecting signal. SOLUTION: In this distance detecting display device having a receiver for radiating a pulse signal as the detecting signal and for receiving and amplifying the reflected signal thereof, for accumulating and memorizing the received and amplified reflected signal intensity in a memory, and for displaying it on a display device, the intensity change of the reflected signal is detected, and the detection result is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance detecting and displaying apparatus, and more particularly to a distance detecting and displaying apparatus for displaying a signal in a detecting distance direction and / or a signal strength change in a time lapse direction of the detecting signal.

[0002]

2. Description of the Related Art A conventional example of a distance detection display device will be described with reference to a fish finder shown in FIG. The fish finder drives the transmitter / receiver 2 with the transmission pulse signal of the ultrasonic wave generated by the transmitter 1 based on the detection sequence.
Radiates an ultrasonic pulse wave toward the sea floor as a detection signal. Then, the reflected wave of the detection signal from the fish school 21, the sea floor 20 and other objects is received by the transmitter / receiver 2. The reflected signal received by the transmitter / receiver 2 is received and amplified by the reception amplifier of the receiver 3. The reflected signal received, amplified, and detected by the receiver 3 is converted into a digital signal by the A / D conversion circuit 4, sampled by the sampling circuit 5, and temporarily stored in the buffer memory 51 as one detection information signal. Is done.

In order to display the detection information signal temporarily stored in the buffer memory 51 on the display device 9, the detection information signal is transferred from the buffer memory 51 to the main memory 6 before the next detection sequence is started. I do. The main memory 6
It has a storage capacity sufficient to store the detection information signals for the number of display pixels of the display device 9 or much larger than this. The detection information signal transferred and stored in the main memory 6 is further transmitted to the display memory 15 via the graphic processor 7.
Is transferred and stored as data for one screen. The detection information signal stored in the display memory 15 is displayed on the display screen of the display device 9 as one-screen display data by the graphic processor 7 and the display device driving circuit 8. In this display, one detection information signal is displayed on the display device 9.
Is displayed as one display line in the vertical direction at the right end of the display screen of FIG. The oldest one detection information signal is displayed on the display device 9.
Are displayed as one display line in the vertical direction at the left end of the display screen. That is, the new detection information signal for one time is always displayed as one display line in the vertical direction at the right end of the display screen of the display device 9 and is sequentially deleted from the oldest detection information signal for one time.

Each component of the fish finder is connected to a CPU 11 as shown in the figure. Then, the control is performed based on the control information stored in the ROM and the RAM as the internal memories. The operation of the fish finder is C
This is executed by the PU 11. Here, reference numeral 10 denotes an original oscillator that generates a clock pulse, a sampling signal, and other signals. Reference numeral 11 denotes a CPU that executes arithmetic processing.
Reference numeral 12 denotes a detection sequencer that controls the generation of transmission pulses of the transmitter 1 and the sampling control circuit 13 based on control programs and control data stored in the ROM 111 and the RAM 112, which are internal memories of the CPU 11. The sampling control circuit 13 performs sampling based on a control signal generated by the detection sequencer 12.
The detection information signal is sampled and taken into the buffer memory 51 of FIG. The detection sequencer 12 further controls the sampling control circuit 13 and performs an operation of capturing the detection information signal captured via the memory control unit 14 into the main memory 6.

The display of a reflected signal by the fish finder will be described with reference to FIGS. 5 and 6. FIG. FIG. 5A is a diagram showing a detection signal radiated from the transducer 2 toward the sea floor, and a reflected signal from a school of fish, the sea floor, and other objects. FIG.
FIG. 5B is an enlarged view of the reflected signals of the fish school and the seabed in FIG. 5A. FIG. 5E is a diagram illustrating color conversion. The received reflected signal of the school of fish in FIG. 5A is amplified and detected, converted into a digital signal in the A / D conversion circuit 4, and then displayed in color according to the color conversion level. Referring to FIG. 5 (e), the reflected signal exceeding the maximum display color level is unified to the color displaying the maximum intensity, similarly to the saturated signal shown in FIG. 5 (g). FIG. 6A shows this display example. The vertical cross section AA ′ in FIG. 6A corresponds to the reflected signal of the school of fish in FIG. 5A.
According to this, the high intensity area near the center is displayed with the same color and the maximum display color level.

[0006]

The above-described fish finder employs a configuration in which an object is displayed and recognized by focusing on the strength of the reflected signal of the detection signal. In particular, all reflected signals exceeding a certain intensity are treated as reflected signals having the same intensity and the maximum display color level. For this reason, even if there is any variation or difference in these reflected signals while the intensity exceeds this fixed intensity, it cannot be displayed and recognized.

When the reflected signal intensity is displayed in color, the high-intensity reflected signal corresponds to an enhanced color such as red. When a monochrome display is performed, a high-intensity reflected signal corresponds to a dark display. However, if a high-intensity reflected signal is displayed in accordance with a dark display or an enhanced color such as red, it becomes difficult to visually recognize a low-intensity reflected signal displayed adjacent to a peripheral region where a high-intensity display is performed. There are cases. Further, it is not possible to display a strong change in the strong reflected signal level exceeding the display conversion level.

The present invention provides a distance detection display apparatus which detects and displays a change in the intensity of a reflection signal of a detection signal and solves the above-described problem.

[0009]

Means for Solving the Problems Claim 1 has a receiver 3 and / or 3 'for radiating a pulse signal as a detection signal and for receiving and amplifying the reflected signal, and for receiving and amplifying the reflected signal strength. In the distance detection display device that stores and stores the information in the memory 6 and displays it on the display device, a distance detection display device that detects a change in the intensity of the reflected signal and displays the detection result is configured. Claim 2: In the distance detecting and displaying apparatus according to claim 1, the receiver 3 'constitutes a distance detecting and displaying apparatus including a differentiating circuit section 32 for detecting and outputting the intensity change rate of the reflected signal. did.

In a preferred embodiment of the present invention, the first receiver 3 'includes a differentiating circuit 32 for detecting and outputting the intensity change rate of the reflected signal.
And a second receiver 3 that receives and amplifies the reflected signal and outputs the reflected signal as it is. Further, in the distance detection display device according to the present invention, the receiver 3 ′ has a distance detection display device including a switch unit 62 for selecting an input to the differentiating circuit unit 32. .

Here, in the distance detection display device according to claim 5, the display of the output of the first receiver 3 'and the display of the output of the second receiver 3 are performed. A distance detection display device that switches to the same screen and displays the image is configured.
Claim 6: In the distance detection display device according to claim 3, display of the output of the first receiver 3 ';
The distance detection display device is configured to simultaneously display the output of the second receiver 3 on the same screen.

Here, claim 7: in the distance detection display device according to claim 1, a level difference for comparing and detecting the intensity of the reflected signal stored and stored in the memory 6 for each bit adjacent to each other in the depth axis direction. A distance detection display device including the detection processing unit 70 was configured. Claim 8: In the distance detection display device according to claim 1, a level difference detection processing section 7 for comparing and detecting the intensity of the reflected signal stored and stored in the memory 6 for each bit adjacent to each other in the time axis direction.
0 was constructed.

Claim 9: In the distance detection display device according to any one of claims 7 and 8, the output of the level difference detection processing unit 70 and the reflection stored in the memory 6 are stored. A distance detection display device configured to switch and display the signal strength is configured. Claim 10: Claim 7
9. The distance detection display device according to claim 8, wherein the output of the level difference detection processing unit 70 and the reflected signal strength stored and stored in the memory 6 are simultaneously displayed on the same screen. The distance detection display device is constructed.

In a preferred embodiment of the present invention, the receiver 3 comprises a distance detecting and displaying device including a log amplifier. . Here, claim 12: In the distance detection display device according to any one of claims 9 and 10, the detection result of the level difference detection processing unit 70 is multiplied by a coefficient to emphasize the detection result. The distance detection display device is constructed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to embodiments. (First Embodiment) In a first embodiment of the present invention, in a fish finder illustrated and described with reference to FIG. 1, a receiver 3 is provided with a differential for detecting and outputting the intensity change rate of a received amplified reflection signal. The circuit 32 corresponds to the receiver 3 ′ of FIG. 2 in which the circuit 32 is connected to the reception amplifier 31.

Hereinafter, a specific description will be given also with reference to FIG. The transmitter / receiver 2 is driven by an ultrasonic transmission pulse signal generated by the transmitter 1, and the pulse signal is emitted from the transmitter / receiver 2 toward the sea floor as a detection signal. The emitted detection signal is reflected by the school of fish 21, the seabed 20, and other objects,
It arrives at the first receiver 3 'and is received. The received reflected signal is input to the reception amplifier 31 and amplified. FIG.
(A) shows the reflected signal after amplification output from the reception amplification unit 31. When a part of the amplified reflected signal is shown in an enlarged manner, the intensity of the signal changes in a complicated manner as shown in FIG. 5B. In other words, the waveform of the reflected signal is not simply a waveform that monotonically increases and decreases from the beginning to the end of the reflected signal, but a waveform that constantly increases and decreases depending on the condition of the fish school, the quality of the seabed, the shape, and other conditions. It is. The reflected signal that changes by repeatedly increasing and decreasing the intensity is input to the differentiating circuit unit 32, and is subjected to a differentiating operation. FIG.
The waveform shown in FIG. 5C shows the waveform after the waveform shown in FIG. The differentiated waveform is then input to the waveform shaping section 33, where the waveform is shaped and output. The waveform shaping uses, for example, a clamp circuit that corrects a negative level to a reference zero level. In this case, the differentiated waveform after the waveform shaping is shown in FIG. The reflected signal subjected to the differentiation operation and the waveform shaping is supplied to the A / D conversion circuit 4. A / D conversion circuit 4
The processing operation of the reflected signal in the subsequent circuit unit is the same as the processing operation in the conventional example. That is, the reflected signal is subjected to a differentiation operation and then supplied to the A / D conversion circuit 4, converted into a digital signal, sampled in the sampling circuit 5, and temporarily stored in the buffer memory 51 as one detection information signal. Is done.

Here, one detection information signal stored in the buffer memory 51 arrives at the first receiver 3 ',
It is not the intensity of the amplified reflected signal itself, but the rate of change of the reflected signal intensity obtained by performing a differential operation on the incoming reflected signal. In this embodiment, the display is made on the display device 9 based on the change rate of the reflected signal intensity. That is, if the reflected signal intensity itself shown in FIG. 5E is displayed in correspondence with the color conversion level, the strong signal intensity portion is saturated and rounded to the same maximum display color level, so that the maximum display Changes in signal strength above the color level are no longer distinguishable. However, in this embodiment, the detection information signal is obtained for the rate of change of the intensity of the reflected signal, and the level range of the rate of change of the intensity of the reflected signal is relatively narrow as shown in FIG. There is no need to consider saturation. A change in the intensity of the strong reflected signal at or above the maximum display color level sufficiently falls within the color conversion level, and is not saturated and expressed in the same color.

(Second Embodiment) A second embodiment will be described with reference to FIG. In the second embodiment, the second receiver 3 of the conventional example and the first receiver 3 'of the first embodiment are provided in parallel, and the second receiver 3 and the first receiver 3 are provided. '
And a changeover switch unit 61 for switching and connecting the A / D converter 4. Switch 61
To switch the A / D converter 4 to the first receiver 3 ′ or switch the A / D converter 4 to the second receiver 3. When the second receiver 3 is switched to the A / D converter 4 by controlling the switch 61, the display device 9 detects and displays the absolute intensity of the reflected signal. When the first receiver 3 ′ is connected to the A / D converter 4 by switching the switch 61 in the opposite direction, the display device 9 detects and displays the intensity change rate of the reflected signal. The fisherman can perform more appropriate fish school detection by switching between the detection display of the absolute intensity and the detection display of the intensity change rate and referring to the display.

(Third Embodiment) A third embodiment will be described with reference to FIG. This third embodiment differs from the second embodiment shown and described with reference to FIG.
Instead of an amplifier unit switch unit 62 for switching the reception amplifier unit 31 to the differentiating circuit unit 32 and the switch unit 61. The changeover switch unit 61 and the amplification unit changeover switch unit 62 switch in conjunction with each other. By switching the changeover switch unit 61 and the amplification unit changeover switch unit 62 to the upper side, the reception amplification unit 31 is switched and connected to the differentiating circuit unit 32, and the reception amplified signal is changed as the change rate of the reflection signal intensity. Is sent to the A / D converter 4 via the. By switching the changeover switch section 61 and the amplification section changeover switch section 62 to the lower side, the reception amplification section 3
1 is directly connected to the A / D converter 4 via the amplifying section changeover switch section 62 and the changeover switch section 61.
The intensity of the amplified reflected signal itself is sent to the A / D converter 4. As described above, in the third embodiment,
It is possible to switch and display the intensity of the reflected signal and the change rate of the intensity of the reflected signal more easily than in the second embodiment of FIG.

(Fourth Embodiment) A fourth embodiment will be described with reference to FIG. The reflected signal received by the second receiver 3 is received and amplified, converted into a digital signal by the A / D conversion circuit 4, sampled by the sampling circuit 5, and temporarily stored in the buffer memory 51 as one detection information signal. And transferred to the main memory 6 via the buffer memory changeover switch 63. on the other hand,
The reflection signal received by the first receiver 3 ′ is amplified by the reception amplifier 31 and differentiated by the differentiator 32.
The waveform is shaped by the waveform shaping unit 33, and the A / D conversion circuit 4
Is converted into a digital signal by the sampling circuit 5
Are temporarily stored as one detection information signal in the buffer memory 51 and transferred to the main memory 6 via the buffer memory changeover switch 63.

The above buffer memory changeover switch 6
Reference numeral 3 denotes an electronic switch for performing a high-speed switching operation. The second receiver 3 and the first receiver 3 ′ are connected to the output terminal of the transducer 2 and the buffer memory switch 63.
, And the same reflected signal is supplied from the transmitter / receiver 2 in time. By switching the buffer memory changeover switch 63 at high speed, the buffer memories 5
1 by temporarily transferring the detection information signal temporarily stored in the main memory 6 to the main memory 6, thereby storing the stored contents of the intensity of the reflected signal passing through the second receiver 3 and stored in the main memory 6. The stored contents of the rate of change of the intensity of the reflected signal passing through one receiver 3 ′ are the same at the same time in time.

The two types of detection information signals stored in the main memory 6 are read out by the graphic processor 7,
The data is written to the display memory 15. Thereby, two types of detection information signals are simultaneously displayed on the display device 9. The fisherman can execute more appropriate fish school detection by simultaneously referring to the detection display of the intensity change rate and the detection display of the absolute intensity. Here, the buffer memory changeover switch 63 is not switched, and is fixed in the upward direction, so that only the change rate of the reflected signal intensity can be displayed. Then, by switching and fixing the buffer memory changeover switch 63 downward, only the reflected signal intensity itself can be displayed.

(Fifth Embodiment) In the above embodiments, the distance detection display device displays the rate of change of the signal strength for the signal in the detection distance direction. However, it is also possible to configure a distance detection display device that converts not only the signal in the detection distance direction but also the change rate of the signal intensity in the time lapse direction by color conversion and displays it. This will be described as a fifth embodiment with reference to FIG.

In the fifth embodiment, the receiving amplifier 31 of the second receiver 3 is a log amplifier in the conventional example shown and described with reference to FIG. 1, and the output terminal of the main memory 6 and the input terminal of the graphic processor 7 are used. And a level difference detection processing unit 70 is connected between them. In FIG. 8, the reception amplifier of the second receiver 3 is particularly configured by a reception log amplifier circuit. The A / D converter 4 is constituted by the high-resolution A / D converter 4. The reception amplifying section is constituted by a reception log amplifier circuit section, amplifies the reflected signal in a wide signal intensity range without saturating the signal, further A / D-converts the signal by the high-resolution A / D converter 4, and converts this into a sampling circuit. 5 is stored in the buffer memory 51. As a result, A / D conversion can be performed and stored without saturating even at a strong signal intensity and without losing a change at a strong signal intensity.

In the fifth embodiment described with reference to FIG. 8, the detection information signal transferred and stored in the main memory 6 is transferred and stored as data for one screen in the display memory 15 via the graphic processor 7. At this time, it is supplied to the level difference detection processing unit 70. When the level difference detection processing unit 70 performs the setting y for obtaining the level difference, the reflection signal intensity of the point on the display line shown in FIG. The intensity of the read bit at the point before the bit is compared with the intensity of the reflected signal. The display color level is determined in accordance with the difference between the reflected signal intensities. Here, in order to determine the display color level, the intensity difference of the obtained reflected signal is selectively multiplied by a coefficient to increase or decrease the intensity difference of the reflected signal. As an example, when the intensity difference of the obtained reflected signal is small, a large coefficient can be selectively multiplied by this to emphasize the intensity difference of the reflected signal, and display on the display device 9 can be optimized. Conversely, when the level difference detection processing unit 70 performs the setting n that does not take the level difference, the level difference detection processing unit 70 converts the detection information signal transferred and stored in the main memory 6 into
Display memory 1 directly via graphic processor 7
5 is transferred and stored as data for one screen.
The detection information signal stored in the display memory 15 is directly displayed on the display screen of the display device 9 as one-screen display data by the graphic processor 7 and the display device driving circuit 8. That is, by setting the level difference detection processing unit 70 to the setting y for obtaining the level difference, the display device 9 detects and displays the intensity change rate of the reflected signal. By setting the setting n so as not to take a level difference, the display device 9 detects and displays the absolute intensity of the reflected signal. As shown in FIG. 9B, when a configuration is used in which the reflected signal intensity of the read bit at a point on the display line is compared with the reflected signal intensity of the read bit at a point one bit earlier, the fish school shown in FIG. This is suitable for observing the vertical state of the reflected signal.

In the above-described embodiment, the description has been made of the case where the reflected signal intensity is displayed only with the signal compared and detected by the level difference detection processing unit 70 and the case where the reflected signal intensity is displayed only with the signal which does not take the level difference. Here, when reading the detection signal from the main memory 6, the detection signal is written in the display memory 15 while the operation of taking the level difference and the operation of not taking the level difference are performed alternately, so that the reflection signal is applied to the display device 9. A signal whose intensity is compared and detected by the level difference detection processing unit 70,
It is possible to simultaneously display signals that do not take a level difference. As described above, when simultaneously displaying a signal detected and a signal that does not take a level difference and a signal that does not take a level difference, the display device is divided into a signal display and a signal display that does not take a level difference. Can be realized by giving necessary instructions to the graphic processor 7.

FIG. 10 shows a case where the level difference detection processing unit 70 is set to the setting y for obtaining a level difference, as shown in FIG. 10 (b) according to the flowchart shown in FIG. 10 (a).
The reflected signal intensity of the read bit between two points on the display line adjacent to each other in the time axis direction is compared. The display color level is determined in accordance with the difference between the reflected signal intensities. Here, to determine the display color level, the intensity difference of the obtained reflected signal is selectively multiplied by a coefficient to increase the intensity difference of the reflected signal,
Or weaken. As an example, when the intensity difference of the obtained reflected signal is small, a large coefficient is selected and multiplied to emphasize the intensity difference of the reflected signal, and the display on the display device 9 can be optimized. Conversely, when the level difference detection processing unit 70 is set to n which does not take a level difference, the detection information signal stored in the main memory 6 is directly sent to the display memory 15 via the graphic processor 7. An operation of transferring and storing the data for the screen is performed. Display memory 15
Is directly displayed on the display screen of the display device 9 as one-screen display data by the graphic processor 7 and the display device driving circuit 8 as it is. That is, by setting the level difference detection processing section 70 to the setting y for obtaining the level difference, the display device 9 detects and displays the intensity change rate of the reflected signal. By setting the setting n so as not to take a level difference, the display device 9 detects and displays the absolute intensity of the reflected signal. In the case of employing a configuration for comparing the reflected signal strengths of read bits between two adjacent points on adjacent display lines as shown in FIG. 10B, the horizontal state of the reflected signal of the school of fish shown in FIG. It is suitable for observation.

In the above-described embodiment, the description has been made of the case where the reflected signal intensity is displayed only by the signal which is compared and detected by the level difference detection processing section 70, and the case where the reflected signal intensity is displayed only by the signal which does not take the level difference. Here, when reading the detection signal from the main memory 6, the detection signal is written in the display memory 15 while the operation of taking the level difference and the operation of not taking the level difference are performed alternately, so that the reflection signal is applied to the display device 9. A signal whose intensity is compared and detected by the level difference detection processing unit 70,
It is possible to simultaneously display signals that do not take a level difference. As described above, when simultaneously displaying a signal detected and a signal that does not take a level difference and a signal that does not take a level difference, the display device is divided into a signal display and a signal display that does not take a level difference. Can be realized by giving necessary instructions to the graphic processor 7.

FIG. 6B shows that the intensity of the reflected signal is as shown in FIG.
FIG. 9 shows a display image according to the present invention when the strong intensity portion does not change as shown in FIG. This is shown in FIG.
It can be understood from the result of differentiating (g) and shaping the waveform as shown in FIG. FIG. 6C shows a display image in the case where the intensity of the reflected signal also changes in the strong intensity portion as shown in FIG. 5E. This is understood from the fact that the differential waveform in FIG. 5E is as shown in FIG. FIG. 6 (d)
Shows another reflected signal display image when the strong intensity portion is changed. That is, it is possible to display a difference in a change in a strong intensity portion.

[0030]

As described above, the conventional example of the fish finder detects and recognizes the target by displaying the intensity of the reflected signal of the detection signal, and sufficiently displays the change in the intensity. It was hard to say that I could do it. In particular, even if there is any variation or difference in the reflected signal intensity in a region of the signal intensity exceeding the maximum display color level, this is saturated at the maximum display color level and cannot be recognized. And I was disturbed by the display of strong signal strength,
In some cases, it is difficult to visually recognize a reflected signal having a weak signal strength displayed adjacent to the peripheral area where the display is performed.

On the other hand, the present invention employs a configuration for detecting and displaying a change in the intensity of the reflection signal of the detection signal, and displaying a detection result of the change in the intensity of the reflection signal of the detection signal to thereby display a strong signal. Even if an intensity change occurs within the intensity range, it can be naturally recognized and displayed. That is,
In the conventional fish finder, even when the display shown in FIG. 6A is made, according to the present invention, the intensity change within the strong signal intensity range is also displayed.
As shown in FIG. 6 (c) and FIG. 6 (d), a difference is given to the display, so that a change in intensity within a strong signal intensity range can be recognized. This is the density of the school of fish, the movement of the fish,
It is useful for discriminating fish species and for determining the quality and shape of the seabed.

In general, a large fish school and a dark plankton layer on the surface layer receive a strong intensity reflected signal continuously. In this case, in a color fish finder that displays in a color-coded manner according to the intensity of the reflected signal of the detection signal, a uniform color corresponding to the large fish school and the dark plankton layer is displayed. According to the present invention, the change in the intensity of the reflected signal within the strong signal intensity range is also displayed, so that if there is a change in the intensity of the reflected signal, the color display changes accordingly. This change in the color display can be used as a reference for discriminating the properties of fish schools and fish species.

Further, according to the present invention, a configuration for amplifying and detecting a reflection signal of a received detection signal and outputting it as it is, and a configuration for detecting and outputting a change in the reflection signal intensity of the received detection signal are provided. By additionally providing and switching, the conventional intensity detection display emphasizing the absolute intensity of the reflected signal and the intensity detection display emphasizing the intensity change are performed together. This allows the fisherman to recognize the detection display of the intensity change occurring within the strong signal strength range exceeding the maximum display color level, in addition to the detection display of the absolute intensity below the maximum display color level. Appropriate fish detection can be implemented.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a fish finder.

FIG. 2 is a diagram illustrating a first embodiment.

FIG. 3 is a diagram illustrating a second embodiment.

FIG. 4 is a diagram illustrating a third embodiment.

FIG. 5 is a diagram showing a reflection signal and the differentiation of the reflection signal.

FIG. 6 is a diagram illustrating a display image.

FIG. 7 is a diagram illustrating a fourth embodiment.

FIG. 8 is a view for explaining a fifth embodiment;

FIG. 9 is a diagram illustrating a level difference detection processing unit.

FIG. 10 is a diagram illustrating another level difference detection processing unit.

Claims (12)

[Claims] 1. A distance detecting display which radiates a pulse signal as a detection signal and receives and amplifies a reflected signal thereof, and stores and stores the received amplified reflected signal intensity in a memory and displays it on a display device. An apparatus for detecting a distance, wherein a change in intensity of a reflected signal is detected and a result of the detection is displayed. 2. The distance detection display device according to claim 1, wherein the receiver includes a differentiating circuit for detecting and outputting the intensity change rate of the reflection signal. 3. The distance detection display device according to claim 1, further comprising: a first receiver including a differentiating circuit for detecting and outputting the intensity change rate of the reflected signal; and receiving and amplifying the reflected signal and outputting it as it is. And a second receiver. 4. The distance detection display device according to claim 2, wherein the receiver includes a switch unit that selects an input to the differentiation circuit unit. 5. The distance detection display device according to claim 3, wherein the display of the output of the first receiver and the display of the output of the second receiver are switched and displayed on the same screen. A distance detection display device characterized by the above-mentioned. 6. The distance detection display device according to claim 3, wherein the display of the output of the first receiver and the display of the output of the second receiver are simultaneously displayed on the same screen. Characteristic distance detection display device. 7. The distance detection display device according to claim 1, further comprising a level difference detection processing unit for comparing and detecting the reflected signal strength stored and stored in the memory for each bit adjacent to each other in the depth axis direction. A distance detection display device characterized by the above-mentioned. 8. The distance detection display device according to claim 1, further comprising a level difference detection processing unit for comparing and detecting the intensity of the reflected signal stored and stored in the memory for each bit adjacent to each other in the time axis direction. A distance detection display device characterized by the above-mentioned. 9. The distance detection display device according to claim 7, wherein an output of said level difference detection processing unit and a reflection signal intensity stored and stored in said memory are stored. And a distance detection display device characterized by switching and displaying. 10. The distance detection display device according to claim 7, wherein an output of said level difference detection processing unit and a reflection signal intensity stored and stored in said memory are stored. And a distance detection display device for simultaneously displaying on the same screen. 11. The distance detection display device according to claim 7, wherein the receiver includes a log amplifier unit. 12. The distance detection display device according to claim 9, wherein the detection result of the level difference detection processing unit is multiplied by a coefficient to emphasize the detection result. Characteristic distance detection display device.