Underwater sensor

Abstract

To provide an underwater sensor capable of jointly changing luminance of light in a display area and in a predetermined area other than the display area and adjusting the luminance in the predetermined area with a simple configuration.SOLUTION: In an underwater sensor (fish finder 12), the luminance of light emitted from a display area (display 15) and the luminance of light emitted from a predetermined area (operation button 17 or the like) are controlled by a control section 200 on the basis of the degree of luminance received by a luminance reception section (power button 14). The control section 200 includes: a first luminance adjustment section for changing the luminance of light emitted from the display area (display 15) essentially continuously relative to a change in the degree of luminance received by the luminance reception section (power button 14); and a second luminance adjustment section for changing the luminance of light emitted from the predetermined area (operation button 17 or the like) in steps relative to a change in the degree of luminance received by the luminance reception section (power button 14).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an underwater detection device that detects a detection target based on the reflected waves of ultrasonic waves transmitted underwater. [Background technology]

[0002] Underwater detection devices such as fish finders are known as devices that detect underwater objects such as schools of fish by transmitting and receiving ultrasonic waves (for example, Patent Document 1). Underwater detection devices transmit (irradiate) thin beam-shaped ultrasonic waves from a transducer placed on the bottom of a ship, for example, toward the water or the bottom of the water. The transmitted ultrasonic waves are reflected from objects to be detected at various depths underwater and from the bottom of the water.

[0003] Based on the received signal obtained when a transducer receives reflected waves from a detection target or the bottom of the water, the underwater detection device forms a detection image indicating, for example, the location of the object that reflected the ultrasound and its reflection intensity (level), and displays the image on a display device.

[0004] The main body of such an underwater detection device (a housing having a display device and operation buttons) is usually used on the bridge or cabin of a ship, or outdoors, such as on a lake. Users will operate the underwater detection device in a variety of situations, such as before dawn when it is still dark, or during the day when it is bright. For this reason, underwater detection devices are designed to allow the brightness (luminance) of the display screen in the display area to be adjusted. Some operation buttons are also equipped with backlights to improve visibility.

[0005] For example, the display device described in Patent Document 2 includes a backlight light source that illuminates the display from behind in accordance with the brightness of the surroundings, an LED that illuminates the operation buttons, and a light source control unit that adjusts the brightness of the backlight light source and the LED in conjunction with each other. This light source control unit includes a first driver that reads out a duty ratio corresponding to an input brightness setting value from a table and controls the brightness of the backlight light source according to a PMW signal of the read duty ratio, and a second driver that controls the brightness of the LED. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2013-079813 A [Patent Document 2] JP 2012-129004 A Summary of the Invention [Problem to be solved by the invention]

[0007] The light source control unit described in Patent Document 2 precisely sets the LED brightness when the operation button is illuminated in conjunction with the brightness of the display backlight light source, but the LED brightness does not require finer adjustment than the backlight light source that illuminates the display. However, if the LED brightness is finely adjusted in the same way as the display backlight light source, the hardware resources required for this would increase and the software would become more complex, resulting in problems with increased processing costs.

[0008] The present invention has been made to solve the above-mentioned problems, and aims to provide an underwater detection device that can adjust the brightness of a specified area other than the display area with a simple configuration while changing the brightness of the light of the display area and the specified area other than the display area in conjunction with each other. [Means for solving the problem]

[0009] In order to achieve this object, a first aspect of the present invention is an underwater detection device comprising: a transducer capable of transmitting ultrasonic waves underwater and receiving the reflected waves; a display area for displaying an image generated based on a received signal generated when the transducer receives the reflected waves of the ultrasonic waves transmitted by the transducer; a light-emitting unit that emits a predetermined light in a predetermined area separate from the display area; a brightness receiving unit that receives a degree of brightness of light emitted from the display area from a user; and a control unit that adjusts the brightness of the light emitted from the display area and the brightness of the light emitted from the predetermined area based on the degree of brightness received by the brightness receiving unit, wherein the control unit comprises a first brightness adjustment unit that adjusts the brightness of the light emitted from the display area so as to change substantially continuously in response to changes in the degree of brightness received by the brightness receiving unit, and a second brightness adjustment unit that adjusts the brightness of the light emitted from the predetermined area so as to change stepwise in response to changes in the degree of brightness received by the brightness receiving unit.

[0010] A second aspect of the present invention is characterized in that, in the underwater detection device of the first aspect, it is provided with a memory unit storing a brightness table in which the brightness levels of light emitted from the display area and the brightness levels of light emitted from the specified area correspond to each of the degrees of brightness received by the brightness receiving unit, and the first brightness adjustment unit refers to the brightness table in the memory unit and adjusts the brightness level of the light emitted from the display area to a brightness level corresponding to the degree of brightness received by the brightness receiving unit, and the second brightness adjustment unit refers to the brightness table in the memory unit and adjusts the brightness level of the light emitted from the specified area to a brightness level corresponding to the degree of brightness received by the brightness receiving unit.

[0011] A third aspect of the present invention is characterized in that, in the underwater detection device of the second aspect, the control unit is provided with a modification unit that changes the brightness table referenced by the first brightness adjustment unit and / or the second brightness adjustment unit based on instructions from a user.

[0012] A fourth aspect of the present invention is characterized in that, in the underwater detection device of the third aspect, the memory unit stores a plurality of brightness tables in which at least one of the brightness levels of light emitted from the display area corresponding to each of the degrees of brightness accepted by the brightness accepting unit and the brightness levels of light emitted from the specified area corresponding to each of the degrees of brightness accepted by the brightness accepting unit is different, and the change unit selects a brightness table to be referenced by the first brightness adjustment unit and / or the second brightness adjustment unit from the plurality of brightness tables based on instructions from a user.

[0013] A fifth aspect of the present invention is characterized in that, in the underwater detection device of the first aspect, it further comprises a brightness change point receiving unit that receives from a user a change in the change point of the brightness of light emitted from the specified area, which changes gradually through adjustment by the second brightness adjustment unit, in response to the change in the degree of brightness received by the brightness receiving unit.

[0014] A sixth aspect of the present invention is characterized in that, in the underwater detection device of the first aspect, the second brightness adjustment unit adjusts the brightness so that light having a predetermined brightness is emitted from the specified area when the degree of brightness accepted by the brightness accepting unit is below a predetermined threshold, and does not emit light from the specified area when the degree of brightness accepted by the brightness accepting unit exceeds a predetermined threshold.

[0015] A seventh aspect of the present invention is characterized in that, in the underwater detection device of the first aspect, the brightness receiving unit is provided with a knob portion that, when rotated by a user, receives the degree of brightness of light emitted from the display area based on the amount of rotation.

[0016] An eighth aspect of the present invention is the underwater detection device according to the seventh aspect, characterized in that the knob portion also serves as a power switch.

[0017] A ninth aspect of the present invention is characterized in that, in the underwater detection device of any of the first to eighth aspects, it is provided with an operation unit that is provided in the specified area and receives instructions related to the operation of the underwater detection device when operated by a user, and the light-emitting unit emits a specified light toward the operation unit. Effect of the Invention

[0018] According to the underwater detection device according to the first aspect of the present invention, an image is displayed in the display area based on a reception signal generated when the transducer receives a reflected wave of an ultrasonic wave transmitted underwater by the transducer. The brightness of the light emitted from the display area is received by the brightness receiving unit, and the brightness of the light emitted from the display area and the brightness of the light emitted from a predetermined area other than the display area are controlled by the control unit based on the brightness of the light received by the brightness receiving unit. The control unit adjusts the brightness of the light emitted from the display area by the first brightness adjustment unit so as to change the brightness substantially continuously in response to the change in the brightness of the degree of the brightness received by the brightness receiving unit. The control unit also adjusts the brightness of the light emitted from the predetermined area by the second brightness adjustment unit so as to change the brightness stepwise in response to the change in the brightness of the degree of the brightness received by the brightness receiving unit. This allows the load related to the processing required to change the brightness of the predetermined area to be reduced by changing the brightness of the predetermined area that does not require fine brightness adjustment stepwise in response to the change in the brightness of the degree of the brightness from the brightness receiving unit. This provides the advantage that the luminance of the light in the display area and in a predetermined area other than the display area can be changed in conjunction with each other, while the luminance of the predetermined area can be adjusted with a simple configuration.

[0019] The underwater detection device according to the second aspect of the present invention achieves the following effect in addition to the effect achieved by the underwater detection device according to the first aspect. That is, a luminance table that predetermines the luminance level of the light emitted from the display area and the luminance level of the light emitted from the predetermined area corresponding to the degree of luminance received by the luminance receiving unit is stored in the storage unit. The first luminance adjustment unit adjusts the luminance level of the light emitted from the display area to the luminance level corresponding to the degree of luminance received by the luminance receiving unit by referring to the luminance table in the storage unit. The second luminance adjustment unit adjusts the luminance level of the light emitted from the predetermined area to the luminance level corresponding to the degree of luminance received by the luminance receiving unit by referring to the luminance table in the storage unit. This has the effect of easily adjusting the luminance level of the light emitted from the display area and the predetermined area to the luminance level corresponding to the degree of luminance received by the luminance receiving unit by referring to the predetermined luminance table from the storage unit.

[0020] The underwater detection device according to the third aspect of the present invention achieves the following effect in addition to the effect achieved by the underwater detection device according to the second aspect. That is, the brightness table referred to by the first brightness adjustment unit and / or the second brightness adjustment unit is changed by the change unit based on an instruction from the user. This allows the user to change the relationship between the degree of brightness accepted by the brightness acceptance unit and the brightness level of light emitted from the display area, which is determined in the brightness table, and / or the relationship between the brightness level of light emitted from the predetermined area in response to a change in the degree of brightness accepted by the brightness acceptance unit, by operating the change unit. This has the effect of allowing the user to change the way in which the brightness level of light emitted from the display area in response to a change in the degree of brightness and / or the way in which the brightness level of light emitted from the predetermined area in response to a change in the degree of brightness, to a form desired by the user.

[0021] The underwater detection device according to the fourth aspect of the present invention has the following effect in addition to the effect of the underwater detection device according to the third aspect. That is, the storage unit stores a plurality of luminance tables in which at least one of the luminance level of the light emitted from the display area corresponding to the degree of luminance received by the luminance receiving unit and the luminance level of the light emitted from the predetermined area corresponding to the degree of luminance received by the luminance receiving unit is different. Then, based on an instruction from a user, the change unit selects the luminance table to be referred to by the first luminance adjustment unit and / or the second luminance adjustment unit from the plurality of luminance tables stored in the storage unit. This has the effect that the manner in which the luminance level of the light emitted from the display area is changed in response to a change in the degree of luminance and / or the manner in which the luminance level of the light emitted from the predetermined area is changed in response to a change in the degree of luminance can be changed according to the user's preference by simply providing the user with a simple operation of selecting the luminance table to be used.

[0022] The underwater detection device according to the fifth aspect of the present invention has the following effect in addition to the effect of the underwater detection device according to the first aspect. That is, the brightness change point receiving unit receives a change in the brightness of the light emitted from the predetermined area, which changes stepwise through adjustment by the second brightness adjustment unit in response to a change in the brightness level received by the brightness receiving unit. This has the effect of making it possible to easily change the brightness level of the light in the predetermined area in response to a change in the brightness level to suit the user's preferences.

[0023] According to the underwater detection device of the sixth aspect of the present invention, in addition to the effects of the underwater detection device of the first aspect, the following effects are achieved. That is, when the degree of brightness received by the brightness receiving unit is equal to or lower than a predetermined threshold, light having a predetermined brightness is emitted from the predetermined area, and when the degree of brightness exceeds the predetermined threshold, the second brightness adjustment unit adjusts the brightness so that light is not emitted from the predetermined area. When the degree of brightness is equal to or higher than the predetermined threshold, it is considered that this corresponds to a case where the surroundings around the underwater detection device are bright and the user wants to increase the brightness level of the display area, but in that case, light emission from the predetermined area is often unnecessary. By preventing light emission from the predetermined area when the degree of brightness exceeds the predetermined threshold, unnecessary light emission can be suppressed, and energy can be saved.

[0024] The underwater detection device according to the seventh aspect of the present invention has the following effect in addition to the effect of the underwater detection device according to the first aspect. That is, when a user rotates the knob, the brightness receiving unit receives the degree of brightness of the light emitted from the display area based on the amount of rotation. This has the effect that the user can input the degree of brightness to the underwater detection device by intuitively rotating the knob, and can easily adjust the brightness of the light emitted from the display area and the specified area.

[0025] The underwater detection device according to the eighth aspect of the present invention has the following effect in addition to the effect of the underwater detection device according to the seventh aspect. That is, when a user operates the knob, the brightness level of the light emitted from the display area is received and the power switch is turned on and off. This has the effect that, by simply rotating the knob, the user can adjust the brightness levels of the display area and the specified area, as well as turn the power of the underwater detection device itself on and off.

[0026] The underwater detection device according to the ninth aspect of the present invention has the following effect in addition to the effect of the underwater detection device according to any one of the first to eighth aspects. That is, the underwater detection device has an operation unit that receives instructions related to the operation of the device. Then, a light-emitting unit that emits a predetermined light in a predetermined area emits light for the operation unit. This has the effect that the light-emitting unit emits light for the operation unit operated by the user, and the brightness of the operation unit can be adjusted in conjunction with the adjustment of the brightness of the display area. [Brief description of the drawings]

[0027] [Figure 1a] 1 is a schematic diagram showing the configuration of a fish finder that is an embodiment of an underwater exploration device of the present invention; [Figure 1b] FIG. 2 is a schematic side view showing the state in which underwater detection is performed by a ship equipped with the fish finder. [Diagram 2] FIG. 2 is a block diagram showing the electrical configuration of the fish finder. [Figure 3a] FIG. 2 is a diagram showing a schematic diagram of a brightness table A stored in the flash memory of the fish finder. [Figure 3b] 13 is a diagram showing the relationship between the knob position and the brightness levels of the first LED and the second LED, as defined in a brightness table A stored in the flash memory of the fish finder. FIG. [Figure 3c] 13 is a diagram showing the relationship between the knob position and the brightness levels of the first LED and the second LED, as defined in a brightness table B stored in the flash memory of the fish finder. FIG. [Figure 3d] 13 is a diagram showing the relationship between the knob position and the brightness levels of the first LED and the second LED, as defined in a brightness table C stored in the flash memory of the fish finder. FIG. [Figure 4] 4 is a flowchart showing a luminance setting process executed by a CPU of the fish finder. [Diagram 5] 4 is a flowchart showing a brightness table selection process executed by a CPU of the fish finder. [Figure 6]FIG. 11 is a block diagram showing the electrical configuration of a fish finder according to a second embodiment. [Figure 7] FIG. 13 is a diagram showing a schematic diagram of a brightness table D stored in the flash memory of the fish finder. [Figure 8] 4 is a flowchart showing a luminance setting process executed by a CPU of the fish finder. [Figure 9] 4 is a flowchart showing a luminance change point reception process executed by a CPU of the fish finder. [Figure 10] FIG. 11 is a block diagram showing the electrical configuration of a fish finder according to a third embodiment. [Figure 11] 13 is a diagram showing a schematic diagram of a brightness table E stored in the flash memory of the fish finder. FIG. [Figure 12] 4 is a flowchart showing a luminance setting process executed by a CPU of the fish finder. [Figure 13] 6 is a flowchart showing a second LED luminance level setting process executed by a CPU of the fish finder. [Figure 14] 4 is a flowchart showing a threshold data changing process executed by a CPU of the fish finder. [Figure 15] 4 is a flowchart showing a level data change process executed by a CPU of the fish finder. [Figure 16] FIG. 13 is a block diagram showing the electrical configuration of a fish detector according to a fourth embodiment. [Figure 17] 13 is a diagram showing a schematic diagram of a brightness table F stored in the flash memory of the fish finder. FIG. [Figure 18] 4 is a flowchart showing a luminance setting process executed by a CPU of the fish finder. [Figure 19] FIG. 13 is a block diagram showing the electrical configuration of a fish detector according to a fifth embodiment. [Figure 20] 4 is a flowchart showing a luminance setting process executed by a CPU of the fish finder. [Figure 21]13 is a flowchart showing a second LED turning-off process executed by a CPU of the fish finder. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, the embodiment for carrying out the present invention will be described with reference to the attached drawings. Note that each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components that are not described in the independent claims showing the highest concept of the present invention will be described as optional components. In addition, in each drawing, the same reference numerals are given to substantially the same configurations, and duplicated descriptions are omitted or simplified.

[0029] (First embodiment) A fish finder 12 according to a first embodiment of the underwater detection device of the present invention will be described with reference to Figures 1 to 5. First, Figure 1a is a schematic diagram showing the configuration of the fish finder 12 of this embodiment, and Figure 1b is a schematic diagram showing a side view of the fish finder 12 mounted on a ship 11 performing underwater detection.

[0030] As shown in Fig. 1b, the fish finder 12 is mounted on a ship 11 and detects a detection target GO such as a school of fish directly below the ship 11 or in the surrounding water. As shown in Fig. 1a, the fish finder 12 is composed of a main body 13, a power button 14, a display 15 formed integrally with the main body 13 and displaying a detection image or the like that is the detection result, an operation button 17 provided on the main body 13 and receiving input from a user, a pilot lamp 19 that indicates the operating state of the fish finder 12, and a transducer 20 that transmits and receives ultrasonic waves TB. Although not shown in Fig. 1a, the fish finder 12 has a first LED (Light-Emitting Diode) 16 (see Fig. 2) behind the display 15 (on the main body side), and a second LED 18 (see Fig. 2) behind the power button 14, the operation button 17, and the pilot lamp 19 (on the main body side).

[0031] The power button 14 is a knob (corresponding to the knob portion of the present invention) that is rotated by the user, and has both the function of a power switch that turns the power of the fish finder 12 on and off, and the function of receiving the brightness level of the light emitted from the display 15. In this embodiment, the power button 14 corresponds to the brightness receiving portion of the present invention.

[0032] The power button 14 outputs a voltage according to the amount of rotation as an analog signal. The fish finder 12 accepts a knob position TL corresponding to the degree of brightness of the light emitted from the display 15 based on the amount of rotation of the power button 14. The user turns the power of the fish finder 12 on and off and adjusts the brightness level of the first LED 16 by rotating the power button 14. In this embodiment, the brightness level of the second LED 18 is adjusted in addition to the brightness level of the first LED 16 by rotating the power button 14. This allows the user to input the degree of brightness of the light emitted from the display 15 to the fish finder 12 by intuitively rotating the knob of the power button 14, so that the brightness of the light emitted from the display 15, as well as the power button 14, the operation button 17, and the pilot lamp 19 (hereinafter, the power button 14, the operation button 17, and the pilot lamp 19 are collectively referred to as the "operation button 17, etc.") can be easily adjusted.

[0033] The display 15 is a liquid crystal display that displays various images including a detection image. In this embodiment, the display 15 corresponds to a display area of ​​the present invention. Note that the display 15 is not limited to a liquid crystal display, and a self-luminous display such as an organic EL (Electro-Luminescence) display may be used.

[0034] The operation buttons 17 are operated by the user and consist of a group of multiple buttons that accept settings related to the operation of the fish finder 12. The operation buttons 17 include a change button 17a (see FIG. 2). The change button 17a is an operation button for accepting changes to settings related to adjustment of the brightness levels of the first LED 16 and the second LED 18. For example, the change button 17a accepts selection of a brightness table to be used from multiple brightness tables described below. In this case, a brightness table selection process described below is executed based on the operation of the change button 17a.

[0035] The pilot lamp 19 is a lamp that indicates to the user whether the power of the fish finder 12 is on or off. By rotating the power button 14, the pilot lamp 19 is lit when the power of the fish finder 12 is on, and the pilot lamp 19 is turned off when the power of the fish finder 12 is off. The pilot lamp 19 is illuminated by the second LED 18. In other words, the brightness of the light emitted from the pilot lamp 19 is also adjusted in response to the rotation of the power button 14.

[0036] The first LED 16 is a backlight that illuminates the display 15 from behind. The brightness level of the light emitted from the first LED 16 is set based on the knob position TL accepted by the power button 14, and is changed by rotating the power button 14. If the display 15 is a self-luminous display, the first LED 16 is not provided since the display 15 emits light by itself. In this case, the brightness level of the light directly emitted from the display 15 is set based on the knob position TL accepted by the power button 14, and is changed by rotating the power button 14.

[0037] The second LED 18 is a backlight that illuminates the operation buttons 17, etc., and is composed of multiple LEDs. The brightness level of the light emitted from the second LED 18 is also set based on the knob position TL received by the power button 14, and is changed by rotating the power button 14.

[0038] The transducer 20 is fixed to the bottom or stern of the ship 11, and is electrically connected to the main body 13 by a cable. The transducer 20 transmits (irradiates) a thin beam-shaped ultrasonic wave TB (see FIG. 1b) in one direction (for example, directly below the ship 11) in response to a signal transmitted from a transmission circuit 209 (see FIG. 2) of the main body 13.

[0039] The transmitted ultrasonic waves TB are reflected by the underwater detection object GO and the bottom of the water, such as the bottom of the sea, lake, river, or pond. The transducer 20 receives the reflected waves of the ultrasonic waves TB reflected by the detection object GO present at each depth and the bottom of the water, and transmits an analog signal corresponding to the reflection intensity of the reflected waves generated by the reception to the receiving circuit 210 (see FIG. 2) of the main body 13.

[0040] The main body 13 is disposed, for example, within the wheelhouse of the ship 11 (see FIG. 1b), and is provided with a control unit 200 shown in FIG. 2 inside. The control unit 200 will now be described in detail with reference to FIG. 2. FIG. 2 is a block diagram showing the electrical configuration of the fish finder 12 of this embodiment. The control unit 200 controls the operation of the fish finder 12, and as shown in FIG. 2, has a CPU (Central Processing Unit) 201, a flash memory 202, and a RAM (Random Access Memory) 203, which are connected to an input / output port 204 via a bus line.

[0041] The control unit 200 is also provided with an AD (Analog-to-Digital) converter 205, a VRAM (Video RAM) 206, a first LED driver 207, a second LED driver 208, a transmission circuit 209, and a reception circuit 210, which are also connected to the input / output port 204. In addition to the operation button 17, the input / output port 204 is also connected with the power button 14 via the AD converter 205, the display 15 via the VRAM 206, the first LED 16 via the first LED driver 207, the second LED 18 via the second LED driver 208, and the vibrator 20 via the transmission circuit 209 and the reception circuit 210.

[0042] The CPU 201 is a central processing unit that executes the main arithmetic processing of the control unit 200. The CPU 201 controls the operation of the fish finder 12 while reading data stored in the RAM 203 based on various programs and fixed value data, including a brightness adjustment program 202a, stored in the flash memory 202. Through the operation of the CPU 201, the control unit 200 functions as a first brightness adjustment unit and a second brightness adjustment unit of the present invention.

[0043] The AD converter 205 converts the analog signal received from the power button 14 into a digital value as knob position reception data ranging from "1" to "255." The knob position reception data is stored as a knob position TL in knob position reception data 203a, which will be described later.

[0044] The flash memory 202 is a rewritable non-volatile memory that stores various programs such as a brightness adjustment program 202a and various fixed value data. The brightness adjustment program 202a is a collection of a series of instructions executed by the CPU 201 to adjust the brightness levels of the first LED 16 and the second LED 18 in particular during the operation of the fish finder 12. The brightness adjustment program 202a also includes programs that cause the CPU 201 to execute the brightness setting process and brightness table selection process shown in Figures 4 and 5.

[0045] Here, the brightness setting process is a process for setting the brightness levels of the first LED 16 and the second LED 18 corresponding to the knob position received from the power button 14 (degree of brightness of light emitted from the display 15).

[0046] The luminance table selection process is a process included in the luminance setting process, and is a process for setting a luminance table to be used in the luminance setting process to a luminance table selected by a user from among a plurality of luminance tables. Details of the luminance setting process and the luminance table selection process will be described later with reference to Figs. 4 and 5.

[0047] The fixed value data stored in the flash memory 202 includes various parameters used to operate the fish finder 12, such as the frequency band of the ultrasonic waves TB used in detection, the detection range (depth) for detecting the detection target GO, etc. The user can change the setting values ​​of some or all of the various parameters by operating the operation button 17.

[0048] 2, as a type of fixed value data, luminance tables A to C and used luminance table type data 202b are stored in the flash memory 202. The luminance tables A to C and used luminance table type data 202b are all fixed value data or parameters used in the luminance setting process and the luminance table selection process.

[0049] The brightness tables A to C are tables that define the brightness levels of the first LED 16 and the second LED 18, which are determined according to the value of the knob position TL of the power button 14. Here, the brightness tables A to C will be described in detail with reference to FIG. 3. FIG. 3a is a diagram that shows a schematic diagram of the brightness table A stored in the flash memory 202 of the fish finder 12 of this embodiment, FIG. 3b is a diagram that shows the relationship between the knob position TL and the brightness levels of the first LED 16 and the second LED 18, which are defined in the brightness table A, FIG. 3c is a diagram that shows the relationship between the knob position TL and the brightness levels of the first LED 16 and the second LED 18, which are defined in the brightness table B, and FIG. 3d is a diagram that shows the relationship between the knob position TL and the brightness levels of the first LED 16 and the second LED 18, which are defined in the brightness table C.

[0050] First, the configuration of the brightness table will be described using brightness table A as an example. As shown in Fig. 3a, brightness table A associates each value of knob position TL that can be received from AD converter 205 connected to power button 14 with a corresponding brightness level of first LED 16 and brightness level of second LED 18. The value of knob position TL is an integer between "1" and "255".

[0051] The configurations of the luminance table B and the luminance table C are the same as the luminance table A. However, the luminance levels of the second LED 18 associated with each value of the knob position TL are different in each luminance table. For example, as shown in FIG. 3b, the luminance table A sets the luminance level of the first LED 16 to the same value as the corresponding knob position TL. That is, the luminance level of the first LED 16 is indicated by "1" to "255". On the other hand, the luminance level of the second LED 18 is set to "1" for knob position TL values ​​of "1" to "99", a luminance level "2" for knob position TL values ​​of "100" to "199", and a luminance level "3" for knob position TL values ​​of "200" to "255". That is, in the luminance table A, the luminance level changes by "1" at the knob position TL positions of "100" and "200". When the relationship between the knob position TL and the first LED 16 and the second LED 18 is shown in a graph, as shown in FIG. 3b, the brightness level of the first LED 16 increases substantially continuously, while the brightness level of the second LED 18 increases in a stepwise manner.

[0052] Next, as shown in FIG. 3c, the brightness table B sets the brightness level of the first LED 16 to the same value as the corresponding knob position TL. On the other hand, the brightness level of the second LED 18 is set to "1" for knob position TL values ​​of "1" to "49", to "2" for knob position TL values ​​of "50" to "149", and to "3" for knob position TL values ​​of "150" to "255". That is, the brightness level changes by "1" at knob positions TL of "50" and "150". In the brightness table B, the brightness level of the second LED 18 is set brighter earlier in response to the amount of rotation of the power button 14 compared to the brightness table A.

[0053] Next, as shown in Fig. 3d, the brightness table C sets the brightness level of the first LED 16 to the same value as the corresponding knob position TL. On the other hand, the brightness level of the second LED 18 is set to "1" for knob position TL values ​​of "1" to "49", to "2" for knob position TL values ​​of "50" to "99", and to "3" for knob position TL values ​​of "100" to "255", so that the brightness level changes by "1" for knob positions TL of "50" and "100". Compared to the brightness table B, the brightness level of the second LED 18 is set brighter earlier in response to the amount of rotation of the power button 14 in the brightness table C.

[0054] In this way, the luminance levels of the second LED 18 in the luminance tables A to C are all set to "1" to "3". This allows the second LED 18 to be used with a luminance level that can be changed in three stages, and the second LED driver 208 to be used with a 2-bit DA converter. This allows the hardware cost to be reduced. Also, the memory capacity required for the luminance tables can be reduced.

[0055] Note that the actual luminance for the luminance level of the first LED 16 does not have to match the actual luminance for the luminance level of the second LED 18. For example, the luminance level "1" of the second LED 18 may correspond to the luminance level "50" of the first LED 16, the luminance level "2" of the second LED 18 may correspond to the luminance level "100" of the first LED 16, and the luminance level "3" of the second LED 18 may correspond to the luminance level "200" of the first LED 16.

[0056] The used luminance table type data 202b stores data for specifying a luminance table to be used for referring to the luminance levels of the first LED 16 and the second LED 18 for the received knob position TL. In the case of this embodiment, one of the types "0" corresponding to the luminance table A, "1" corresponding to the luminance table B, and "2" corresponding to the luminance table C is stored.

[0057] In addition, the control unit 200 may be provided with a ROM (Read Only Memory), which is a non-volatile memory that cannot be rewritten, instead of or in addition to the flash memory 202, and part or all of the brightness adjustment program 202a or part or all of the fixed value data may be stored in the ROM.

[0058] The RAM 203 is a rewritable volatile memory, and temporarily stores various data when the CPU 201 performs calculation processing according to a program such as the brightness adjustment program 202a. The RAM 203 stores at least knob position reception data 203a as various data.

[0059] The knob position reception data 203a is the value of the knob position TL received from the power button 14 (more precisely, the AD converter 205) in order to set the luminance levels of the first LED 16 and the second LED 18. The knob position TL is a variable corresponding to the rotation position of the power button 14, and is an integer between "1" and "255".

[0060] The VRAM 206 is a memory that stores image data of images to be displayed on the display 15, including a detection image that is a detection result of the fish finder 12. The CPU 201 generates image data of images to be displayed on the display 15 and stores the image data in the VRAM 206. The display 15 displays various images based on the image data stored in the VRAM 206.

[0061] The first LED driver 207 is a circuit that, based on the luminance level of the first LED 16 output by the CPU 201 in accordance with the luminance adjustment program 202a, causes the first LED 16 to emit light to a luminance indicated by that luminance level.

[0062] The second LED driver 208 is a circuit that, based on the luminance level of the second LED 18 output by the CPU 201 in accordance with the luminance adjustment program 202a, causes the second LED 18 to emit light to a luminance indicated by that luminance level.

[0063] The transmission circuit 209 is a circuit that drives and controls the transducer 20 so as to transmit ultrasonic waves TB based on instructions from the CPU 201 .

[0064] The receiving circuit 210 is a circuit that receives an analog signal corresponding to the reflection intensity of the reflected wave generated when the transducer 20 receives the reflected wave of the ultrasonic wave TB from the transducer 20, converts the analog signal into a digital value indicating the reflection intensity of the reflected wave received by the transducer 20, and transmits the digital value to the CPU 201.

[0065] Next, the operation of the fish finder 12 of the first embodiment configured as described above will be described. The fish finder 12 detects the detection target GO as follows, by the CPU 201 executing various calculations according to programs such as the brightness adjustment program 202a.

[0066] First, when the CPU 201 instructs the transmission circuit 209 to transmit ultrasonic waves TB, the transmission circuit 209 outputs a signal to the transducer 20, and the transducer 20 transmits (radiates) ultrasonic waves TB into the water.

[0067] When the transducer 20 transmits ultrasonic waves TB into water, the receiving circuit 210 converts an analog signal generated when the transducer 20 receives the reflected waves of the ultrasonic waves TB reflected from each depth in water into a digital signal and outputs the digital signal to the CPU 201.

[0068] Based on the digital signal received from the receiving circuit 210, the CPU 201 generates a depth image showing the depth from the water surface to the bottom of the sea, lake, river, pond, etc. around the ship 11 and a detection image showing the depth from the water surface to the detection target GO, and stores them in the VRAM 206. The display 15 displays the depth image and the detection image based on the image data stored in the VRAM 206.

[0069] In this way, the fish finder 12 detects detection targets GO, such as schools of fish in the water, by transmitting and receiving ultrasonic waves TB, and displays them on the display 15. The user performs work while checking the displayed depth image and detection image, but may find them too bright or dark depending on the brightness around the fish finder 12. In this case, the user needs to change the brightness of the first LED 16 that illuminates the display 15. Similarly, the user needs to change the brightness of the second LED 18 that illuminates the operation buttons 17, etc. The process of changing the brightness of the first LED 16 and second LED 18 corresponds to the brightness change process.

[0070] Next, the brightness setting process will be described with reference to Fig. 4. Fig. 4 is a flowchart showing the brightness setting process. The fish finder 12 executes the brightness setting process as follows, as shown in the flowchart of Fig. 4, by the CPU 201 executing various calculations according to the brightness adjustment program 202a. The brightness setting process is started by the CPU 201 when the user rotates the rotation position of the operation button 17 from the power off state to the power on state of the fish finder 12, and the brightness levels of the first LED 16 and the second LED 18 are determined based on the knob position TL of the power button 14, and are output to the corresponding first LED driver 207 and second LED driver 208.

[0071] First, the CPU 201 stores the knob position TL received from the AD converter 205 connected to the power button 14 in the knob position received data 203a of the RAM 203 (S101). The knob position TL stored here is data indicating the rotation position of the operation button 17 for determining the luminance level of the first LED 16 and the luminance level of the second LED 18.

[0072] Then, the CPU 201 reads out the luminance level of the first LED 16 and the luminance level of the second LED 18 corresponding to the knob position TL from the luminance table specified by the used luminance table type data 202b among the luminance tables A to C (S102). The used luminance table type data 202b stores one of the types "0" corresponding to the luminance table A, "1" corresponding to the luminance table B, and "2" corresponding to the luminance table C. The CPU 201 refers to the luminance table corresponding to the type stored in the used luminance table type data 202b, and reads out the luminance level of the first LED 16 and the luminance level of the second LED 18 corresponding to the knob position TL.

[0073] The CPU 201 outputs the read brightness level of the first LED 16 to the first LED driver 207, and outputs the read brightness level of the second LED 18 to the second LED driver 208 (S103). The first LED driver 207 converts the digital value of the brightness level of the first LED 16 output by the CPU 201 into an analog signal and outputs it to the first LED 16. The first LED 16 illuminates the display 15 with a brightness corresponding to the brightness level based on the analog signal of the brightness level. The second LED driver 208 converts the digital value of the brightness level of the second LED 18 output by the CPU 201 into an analog signal and outputs it to the second LED 18. The second LED 18 illuminates the operation button 17 and the like with a brightness corresponding to the brightness level based on the analog signal of the brightness level. For example, when the knob position TL is "1" and the type of the used brightness table type data 202b is "0", the CPU 201 refers to the brightness table A corresponding to the type "0" of the used brightness table type data 202b, and outputs the brightness level value "1" of the first LED 16 and the brightness level value "1" of the second LED 18 corresponding to the knob position TL value "1".

[0074] In this way, the brightness tables A to C in which the brightness level of the first LED 16 for illuminating the display 15 corresponding to the knob position TL received from the power button 14 and the brightness level of the second LED 18 for illuminating the operation buttons 17 and the like are predefined are stored in the flash memory 202. Then, the CPU 201 refers to one of the brightness tables A to C and adjusts the brightness level of the first LED 16 to the brightness level corresponding to the knob position TL received from the power button 14. In this way, the brightness level of the light emitted from the display 15 is adjusted according to the amount of rotation of the power button 14. In addition, the CPU 201 refers to one of the brightness tables A to C and adjusts the brightness level of the second LED 18 to the brightness level corresponding to the knob position TL received from the power button 14. In this way, the brightness level of the light emitted from the operation buttons 17 and the like is adjusted according to the amount of rotation of the power button 14.

[0075] As described above, by referring to the predetermined brightness tables A to C in the flash memory 202, the fish finder 12 can easily adjust the brightness level of the light emitted from the display 15 and the brightness level of the light emitted from the operation buttons 17 etc. to a brightness level corresponding to the degree of brightness received by the power button 14. Note that the CPU 201 executing the process of S103 constitutes a first brightness adjustment unit and a second brightness adjustment unit of the present invention.

[0076] Next, the CPU 201 executes a luminance table selection process (S104). The luminance table selection process is a process for changing the type of the luminance table used to determine the luminance levels of the first LED 16 and the second LED 18 based on an operation by the user.

[0077] The luminance table selection process will now be described with reference to Fig. 5. Fig. 5 is a flow chart showing the luminance table selection process executed by the CPU 201 of the fish finder 12 of this embodiment.

[0078] As shown in Fig. 5, the CPU 201 executes the luminance table selection process as follows. The CPU 201 first judges whether the user has operated the change button 17a to change the luminance table to be used (S201). As a result, if it is judged that the user has operated the change button 17a to change the luminance table (S201: YES), the type of the luminance table selected by the change button 17a is read out (S202). The CPU 201 stores information indicating the type of the read luminance table in the used luminance table type data 202b (S203) and ends the luminance table selection process.

[0079] On the other hand, if it is determined as a result of the process in S201 that the user will not operate the change button 17a to change the luminance table (S201: NO), the luminance table selection process is terminated without going through the processes in S202 and S203.

[0080] In this way, the luminance table selection process selects one luminance table from the plurality of luminance tables A to C stored in the flash memory 202 and changes the type of the used luminance table type data 202b by the user operating the change button 17a. As a result, by simply providing the user with the simple operation of selecting the luminance table to be used, the way in which the luminance level of the light emitted from the display 15 is changed in response to a change in the knob position TL (the amount of rotation of the power button 14) and / or the way in which the luminance level of the light emitted from the operation buttons 17, etc. is changed in response to a change in the knob position TL can be changed to a form desired by the user.

[0081] Returning to Fig. 4, the luminance setting process will be further described. The CPU 201 repeats the processes of S101 to S104 described above until the power supply of the fish finder 12 is turned off. This makes it possible for the user to easily change the luminance levels of the first LED 16 and the second LED 18 to the luminance levels corresponding to the new knob position TL when the user rotates the power button 14 to change the luminance of the display 15.

[0082] For example, when the used brightness table type data 202b is in a state of "0", and the value of the knob position TL is changed from "1" to "50", the CPU 201 refers to the brightness table A and outputs the brightness level value "50" of the first LED 16 and the brightness level value "1" of the second LED 18 corresponding to the knob position TL value "50". In this case, the brightness level of the first LED 16 has changed in response to the change in the knob position TL, but the brightness level of the second LED 18 has not changed. On the other hand, when the knob position TL value is changed from "50" to "100", the CPU 201 refers to the brightness table A and outputs the brightness level value "100" of the first LED 16 and the brightness level value "2" of the second LED 18 corresponding to the knob position TL value "100". In this case, the brightness levels of both the first LED 16 and the second LED 18 have changed in response to the change in the knob position TL.

[0083] In this embodiment, the CPU 201 changes the brightness level of the first LED 16 emitted from the display 15 in a substantially continuous manner in response to the change in the knob position TL received from the power button 14. On the other hand, the CPU 201 changes the brightness level of the second LED 18 emitted from the operation button 17 and the like in a stepwise manner in response to the change in the knob position TL received from the power button 14. This allows the fish finder 12 to reduce the memory capacity required for the brightness table that specifies the brightness level of the second LED 18. In addition, the fish finder 12 can reduce the accuracy of the brightness change required for the second LED 18, and can use a low-bit DA converter for the second LED driver 208. In this way, the fish finder 12 can reduce the load related to the processing required to change the brightness of the operation button 17 and the like by stepwise changing the brightness of the operation button 17 and the like that does not require fine brightness adjustment by operating the power button 14. Therefore, the brightness of the display 15 and the operation buttons 17 etc. can be changed in conjunction with each other, and the brightness of the operation buttons 17 etc. can be adjusted with a simple configuration.

[0084] Second embodiment Next, a schematic configuration of a fish finder 12 according to a second embodiment of the underwater detection device of the present invention will be described with reference to Figs. 6 to 9. In the first embodiment, a plurality of luminance tables (luminance tables A to C) are prepared, and the user of the fish finder 12 can select which luminance table to use to set the luminance levels of the first LED 16 and the second LED 18. In contrast, the fish finder 12 according to the second embodiment uses only one luminance table (luminance table D) as the luminance table, and changes the luminance change point at which the luminance level of the second LED 18 changes with respect to the change in knob position TL, based on the luminance change point shift amount R set by the user. Here, differences from the fish finder 12 of the first embodiment will be described in detail, and the same reference numerals will be used to designate the common configuration, and the description thereof will be omitted.

[0085] 6 is a block diagram showing the electrical configuration of the fish finder 12 of this embodiment. In the fish finder 12 of the second embodiment, a flash memory 202 stores a brightness adjustment program 202c, a brightness table D, and brightness change point setting data 202d.

[0086] The brightness adjustment program 202c of this embodiment is a collection of a series of instructions executed by the CPU 201 to adjust the brightness levels of the first LED 16 and the second LED 18 in particular during the operation of the fish finder 12. The brightness adjustment program 202c also includes a program for the CPU 201 to execute the brightness setting process and brightness change point reception process shown in Figures 8 and 9.

[0087] The brightness table D is a table that specifies the brightness levels of the first LED 16 and the second LED 18 that are determined according to the knob position TL of the power button 14. Details of the brightness table D will now be described with reference to Fig. 7. Fig. 7 is a diagram that diagrammatically shows the brightness table D stored in the flash memory 202 of the fish finder 12 of this embodiment.

[0088] 7, the brightness table D associates each value of the knob position TL that can be received from the AD converter 205 connected to the power button 14 with a corresponding brightness level of the first LED 16 and a corresponding brightness level of the second LED 18. The value of the knob position TL is an integer between "1" and "255".

[0089] In the example shown in FIG. 7, the brightness table D sets the brightness level of the first LED 16 to the same value as the corresponding knob position TL. On the other hand, the brightness level of the second LED 18 is set to "1" for knob position TL values ​​of "1" to "99", to "2" for knob position TL values ​​of "100" to "199", and to "3" for knob position TL values ​​of "200" to "255". That is, the brightness level changes by "1" at knob position TL positions of "100" and "200". In other words, the brightness table D sets the brightness change points at which the brightness level of the second LED 18 changes in response to a change in knob position TL to the knob position TL values ​​of "100" and "200".

[0090] The brightness change point setting data 202d stores a brightness change point shift amount R for shifting the brightness change point of the first LED 16 with respect to the received knob position TL. The brightness change point shift amount R is an integer set within the range of "-50" to "50", for example. The fish finder 12 is configured to be able to change the brightness change point defined in the brightness table D to a position to which the brightness change point shift amount R has been added. The brightness change point shift amount R stored in the brightness change point setting data 202d is changed by the user operating the change button 17a. This allows the user to change the brightness change point at which the brightness level of the second LED 18 changes with respect to the knob position TL to a desired position by changing the brightness change point shift amount R.

[0091] Next, the operation of the fish finder 12 of the second embodiment configured as above will be described with reference to FIG. 8, focusing on the luminance setting process.

[0092] 8 is a flowchart showing the luminance setting process executed by the CPU 201 of the fish finder 12 of this embodiment. The fish finder 12 executes the luminance setting process as follows, as shown in the flowchart of FIG. 8, by the CPU 201 executing various calculations according to the luminance adjustment program 202c.

[0093] First, the CPU 201 stores the knob position TL received from the AD converter 205 connected to the power button 14 in the knob position received data 203a of the RAM 203 (S301). The knob position TL stored here is data indicating the rotation position of the operation button 17 for determining the luminance level of the first LED 16 and the luminance level of the second LED 18.

[0094] Next, the CPU 201 reads out the luminance level of the first LED 16 corresponding to the knob position TL from the luminance table D (S302).

[0095] Next, the CPU 201 executes a luminance change point reception process (S303). The luminance change point reception process is a process for receiving a luminance change point shift amount R for shifting a luminance change point of the luminance level of the second LED 18, and for performing a process required for shifting the luminance change point according to the luminance change point shift amount R.

[0096] The luminance change point reception process will now be described with reference to Fig. 9. Fig. 9 is a flow chart showing the luminance change point reception process executed by the CPU 201 of the fish finder 12 of this embodiment.

[0097] As shown in Fig. 9, the brightness change point reception process is executed as follows. First, the CPU 201 judges whether the user has operated the change button 17a to set the brightness change point shift amount R (S401). As a result, if it is judged that the user has operated the change button 17a to set the brightness change point shift amount R (S401: YES), the CPU 201 reads out the brightness change point shift amount R set by the change button 17a (S402). The CPU 201 stores the read out brightness change point shift amount R in the brightness change point setting data 202d (S403) and proceeds to the process of S404. On the other hand, if it is judged as a result of the process of S401 that the user has not operated the change button 17a to set the brightness change point shift amount R (S401: NO), the processes of S402 and S403 are omitted and the process proceeds to the process of S404.

[0098] In the process of S404, a value obtained by subtracting the brightness change point shift amount R from the knob position TL is substituted for the knob position TL (S404). By using the knob position TL from which the brightness change point shift amount R has been subtracted, and by referring to the brightness table D, the brightness change point of the brightness level of the second LED 18 can be substantially shifted to the addition side by the brightness change point shift amount R without changing the contents of the brightness table D.

[0099] Here, if the value of the knob position TL after subtracting the brightness change point shift amount R exceeds the range of "1" to "255", the corresponding brightness level of the second LED 18 does not exist in the brightness table D and cannot be referenced. Therefore, the following process is performed so that the value of the knob position TL after subtraction does not exceed the range of "1" to "255".

[0100] First, the CPU 201 determines whether the knob position TL value subtracted in the process of S404 is smaller than "1" (S405). If the knob position TL value subtracted is smaller than "1" (S405: YES), the knob position TL is set to "1" (S407), and the luminance change point acceptance process is terminated.

[0101] On the other hand, if the result of the determination in S405 is that the value of the knob position TL after subtraction is equal to or greater than "1" (S405: NO), then the CPU 201 determines whether the value of the knob position TL after subtraction is greater than "255" (S406). As a result, if the value of the knob position TL after subtraction is greater than "255" (S406: YES), the CPU 201 assigns "255" to the knob position TL (S408) and ends the luminance change point acceptance process.

[0102] If it is determined in S406 that the knob position TL after subtraction is equal to or less than 255 (S406: NO), the knob position TL after subtraction entered in S404 is left unchanged and the luminance change point acceptance process is terminated.

[0103] Returning to Fig. 8, the description of the brightness setting process will be continued. After executing the brightness change point reception process of S303, the CPU 201 then reads out the brightness level of the second LED 18 corresponding to the knob position TL after subtraction from the brightness table D (S304). Then, the CPU 201 outputs the brightness level of the first LED 16 read out by the process of S302 to the first LED driver 207, and outputs the brightness level of the second LED 18 read out by the process of S304 to the second LED driver 208 (S305).

[0104] The first LED driver 207 converts the digital value of the brightness level of the first LED 16 output by the CPU 201 into an analog signal and outputs it to the first LED 16. The first LED 16 illuminates the display 15 at a brightness corresponding to the brightness level based on the analog signal of the brightness level. The second LED driver 208 converts the digital value of the brightness level of the second LED 18 output by the CPU 201 into an analog signal and outputs it to the second LED 18. The second LED 18 illuminates the operation buttons 17 and the like at a brightness corresponding to the brightness level based on the analog signal of the brightness level.

[0105] After the process of S305, the CPU 201 returns to the process of S301, and repeatedly executes the processes of S301 to S305 until the power supply of the fish detector 12 is turned off.

[0106] In this way, the user can change the relationship of the luminance level of the second LED 18 to the change in the knob position TL accepted by the power button 14, which is determined in the luminance table D, by setting the luminance change point shift amount R by operating the change button 17a. Therefore, the luminance change point at which the luminance level of the second LED 18 emitted by the operation button 17 etc. changes in response to the change in the knob position TL can be changed to a form desired by the user.

[0107] Third embodiment Next, a schematic configuration of a fish detector 12 according to a third embodiment of the underwater detector of the present invention will be described with reference to Figs. 10 to 15. In the first embodiment, the luminance level of the second LED 18 is defined in association with the knob position TL so that the luminance change points (positions where the luminance level of the second LED 18 changes with respect to the change in the knob position TL) are different in each luminance table. In contrast, the fish detector 12 according to the third embodiment does not define the luminance level of the second LED 18 corresponding to the knob position TL in the luminance table, but instead sets a plurality of luminance change points as the first threshold data TH1 to the fourth threshold data TH4, and sets the luminance level of the second LED 18 by comparing the first threshold data TH1 to the fourth threshold data TH4 with the knob position TL. The fish detector 12 according to the third embodiment is also different from the fish detector 12 according to the first embodiment in that the luminance level of the second LED 18 is set to "0" when the knob position TL is larger than the fourth threshold data TH4. Here, differences from the fish finder 12 of the first and third embodiments will be described in detail, and common points will be given the same reference numerals and description thereof will be omitted.

[0108] In this embodiment, and in the fourth and fifth embodiments described later, the pilot lamp 19 is illuminated by an LED different from the second LED 18. In this case, the brightness of the light emitted from the pilot lamp 19 may be constant regardless of the knob position TL, or may be adjusted according to the change in the knob position TL. Accordingly, in this embodiment, and in the fourth and fifth embodiments described later, the "operation button 17, etc." refers to the power button 14 and the operation button 17.

[0109] 10 is a block diagram showing the electrical configuration of the fish finder 12 of the third embodiment. In the fish finder 12 of the third embodiment, the data stored in the flash memory 202 include a brightness adjustment program 202e, a brightness table E, first threshold data TH1, second threshold data TH2, third threshold data TH3, fourth threshold data TH4, first level data LV1, second level data LV2, third level data LV3, and fourth level data LV4.

[0110] The brightness adjustment program 202e of this embodiment is a collection of a series of instructions executed by the CPU 201 to adjust the brightness levels of the first LED 16 and the second LED 18 in particular during the operation of the fish finder 12. The brightness adjustment program 202e also includes programs for the CPU 201 to execute the brightness setting process, the second LED brightness level setting process, the threshold data changing process, and the level data changing process shown in Figs.

[0111] The brightness table E is a table that associates the brightness level of the first LED 16 determined according to the value of the knob position TL of the power button 14. The brightness table E does not store the brightness level of the second LED 18. Here, the brightness table E will be described in detail with reference to Fig. 11. Fig. 11 is a diagram that shows a schematic diagram of the brightness table E stored in the flash memory 202 of the fish finder 12 of this embodiment.

[0112] 10, the brightness table E associates each value of the knob position TL that can be received from an AD converter 205 (described later) to which the power button 14 is connected with a corresponding brightness level of the first LED 16. The value of the knob position TL is an integer between "1" and "255".

[0113] In the example shown in FIG. 11, the brightness table E sets the brightness level of the first LED 16 to the same value as the corresponding knob position TL.

[0114] The first threshold data TH1, the second threshold data TH2, the third threshold data TH3, and the fourth threshold data TH4 indicate the luminance change points of the luminance level of the second LED 18 with respect to the change of the knob position TL, respectively, and are thresholds used for comparison with the knob position TL in the second LED luminance level setting process described later. The values ​​of the first threshold data TH1 to the fourth threshold data TH4 are each an integer between "1" and "255", and as initial values, for example, the first threshold data TH1 is set to "50", the second threshold data TH2 is set to "100", the third threshold data TH3 is set to "150", and the fourth threshold data TH4 is set to "200". In addition, the values ​​of the first threshold data TH1 to the fourth threshold data TH4 are changed by the user operating the change button 17a within a range in which the relationship of the first threshold data TH1<the second threshold data TH2<the third threshold data TH3<the fourth threshold data TH4 is maintained.

[0115] The first level data LV1 to the fourth level data LV4 are values ​​of the luminance levels of the second LED 18 determined by comparing the knob position TL with the first threshold data TH1 to the fourth threshold data TH4, and are, for example, integers from "1" to "15".

[0116] Specifically, the first level data LV1 is a value of the luminance level of the second LED 18 set when the knob position TL is smaller than the first threshold data TH1. The second level data LV2 is a value of the luminance level of the second LED 18 set when the knob position TL is equal to or larger than the first threshold data TH1 and smaller than the second threshold data TH2. The third level data LV3 is a value of the luminance level of the second LED 18 set when the knob position TL is equal to or larger than the second threshold data TH2 and smaller than the third threshold data TH3. The fourth level data LV4 is a value of the luminance level of the second LED 18 set when the knob position TL is equal to or larger than the third threshold data TH3 and smaller than the fourth threshold data TH4. In this embodiment, when the knob position TL is larger than the fourth threshold data TH4, the luminance level of the second LED 18 is set to "0".

[0117] The first level data LV1 to the fourth level data LV4 are set as initial values, for example, the first level data LV1 is set to "2", the second level data LV2 is set to "6", the third level data LV3 is set to "10", and the fourth level data LV4 is set to "14". In addition, the first level data LV1 to the fourth level data LV4 are changed by the user operating the change button 17a within a range in which the relationship of first level data LV1<second level data LV2<third level data LV3<fourth level data LV4 is maintained.

[0118] Next, the brightness setting process will be described with reference to Fig. 12. Fig. 12 is a flowchart showing the brightness setting process executed by the CPU 201 of the fish finder 12 of this embodiment. As shown in the flowchart of Fig. 12, the fish finder 12 executes the brightness setting process as follows by the CPU 201 executing various calculations according to the brightness adjustment program 202e.

[0119] First, the CPU 201 stores the knob position TL received from the AD converter 205 connected to the power button 14 in the knob position reception data 203a of the RAM 203 (S501). The knob position TL stored here is data indicating the rotation position of the operation button 17 for determining the luminance level of the first LED 16 and the luminance level of the second LED 18.

[0120] Next, the CPU 201 reads out the luminance level of the first LED 16 corresponding to the knob position TL from the luminance table E (S502). The CPU 201 outputs the read luminance level of the first LED 16 to the first LED driver 207 (S503). The first LED driver 207 converts the digital value of the luminance level of the first LED 16 output by the CPU 201 into an analog signal and outputs it to the first LED 16. Based on the analog signal of the luminance level, the first LED 16 illuminates the display 15 with a luminance according to the luminance level.

[0121] Next, a second LED brightness level setting process is executed (S504). The second LED brightness level setting process is a process of comparing the knob position TL with the first threshold data TH1 to the fourth threshold data TH4 prestored in the flash memory 202, and determining the brightness level of the second LED 18 from among five levels based on the comparison result.

[0122] The second LED luminance level setting process will now be described with reference to Fig. 13. Fig. 13 is a flowchart showing the second LED luminance level setting process executed by the CPU 201 of the fish finder 12 of this embodiment.

[0123] As shown in FIG. 13, the CPU 201 executes the second LED brightness level setting process as follows. First, the CPU 201 judges whether the value of the knob position TL received from the power button 14 is greater than the fourth threshold data TH4 (for example, "200") (S601). As a result, if the value of the knob position TL is greater than the fourth threshold data TH4 (S601: YES), the CPU 201 outputs "0" to the DA converter (second LED driver 208) corresponding to the second LED 18 (S607). In other words, if the value of the knob position TL exceeds the fourth threshold data TH4, which is the largest among the first threshold data TH1 to the fourth threshold data TH4, the surroundings of the fish finder 12 are sufficiently bright, and the operation button 17 and the like can be operated without emitting light from the second LED 18. In this case, the CPU 201 sets the brightness level of the second LED 18 to "0" so that the second LED 18 does not emit light, and ends the second LED brightness level setting process. This makes it possible to suppress unnecessary emission of light from the second LED 18 that illuminates the operation buttons 17 and the like, thereby enabling energy saving.

[0124] On the other hand, if the result of the determination in S601 is that the knob position TL is equal to or smaller than the fourth threshold data TH4 (S601: NO), then the CPU 201 determines whether the knob position TL is smaller than the first threshold data TH1 (e.g., "50") (S602). If the result is that the knob position TL is smaller than the first threshold data TH1 (S602: YES), the CPU 201 sets the brightness of the second LED 18 to the value of the first level data LV1 (e.g., "2") (S608), and proceeds to the process of S606.

[0125] If the result of the determination in S602 is that the knob position TL is equal to or greater than the first threshold data TH1 (S602: NO), then the CPU 201 determines whether the knob position TL is smaller than the second threshold data TH2 (e.g., "100") (S603). If the result is that the knob position TL is smaller than the second threshold data TH2 (S603: YES), the CPU 201 sets the brightness of the second LED 18 to the value of the second level data LV2 (e.g., "6") (S609), and proceeds to the process of S606.

[0126] If the result of the determination in S603 is that the knob position TL is equal to or greater than the second threshold data TH2 (S603: NO), then the CPU 201 determines whether the knob position TL is smaller than the third threshold data TH3 (e.g., "150") (S604). If the result is that the knob position TL is smaller than the third threshold data TH3 (S604: YES), the CPU 201 sets the brightness of the second LED 18 to the value of the third level data LV3 (e.g., "10") (S610), and proceeds to the process of S606.

[0127] If the result of the determination in S604 is that the knob position TL is equal to or greater than the third threshold data TH3 (S604: NO), then the CPU 201 sets the brightness of the second LED 18 to the value of the fourth level data LV4 (e.g., "14") (S605), and proceeds to the processing of S606.

[0128] The CPU 201 outputs the set brightness level of the second LED 18 to the 2 LED driver 208 (S606), and ends the second LED brightness level setting process. The second LED driver 208 converts the digital value of the brightness level of the second LED 18 output by the CPU 201 into an analog signal and outputs it to the second LED 18. Based on the analog signal of the brightness level, the second LED 18 illuminates the operation button 17 etc. with a brightness according to the brightness level.

[0129] In this way, the second brightness level setting process compares the value of the knob position TL of the power button 14 with the preset first to fourth threshold data TH1 to TH4, and can easily change the brightness level of the second LED 18 in a stepwise manner, which does not require fine brightness adjustment compared to the brightness level of the first LED 16. Also, in the first embodiment, both the brightness levels of the first LED 16 and the second LED 18 corresponding to the knob position TL are stored as in the brightness table A, whereas in the brightness table E of this embodiment, it is only necessary to store the brightness level of the first LED 16, and the memory capacity required for storing the brightness level of the second LED 18 can be reduced, thereby saving the hardware resources of the fish finder 12.

[0130] Returning to Fig. 12, the description of the brightness setting process will be continued. Following the second LED brightness level setting process (S504), a threshold data change process is executed (S505). The threshold data change process is a process for changing the first threshold data TH1 to the fourth threshold data TH4 used in the above-mentioned second LED brightness level setting process based on an operation by the user.

[0131] Here, threshold data change processing is executed (S505) with reference to Fig. 14. Fig. 14 is a flowchart showing threshold data change processing executed by the CPU 201 of the fish detector 12 of this embodiment.

[0132] As shown in Fig. 14, the CPU 201 executes the threshold data change process as follows. First, the CPU 201 judges whether the user has operated the change button 17a to change the first to fourth threshold data TH1 to TH4 to be used (S701). As a result, if it is judged that the user has operated the change button 17a to change the first to fourth threshold data TH1 to TH4 (S701: YES), the CPU 201 reads out the threshold data set by the change button 17a (S702). Then, the CPU 201 stores the read out threshold data in the first to fourth threshold data TH1 to TH4 (S703) and ends the threshold data change process.

[0133] On the other hand, if it is determined as a result of the processing in S701 that the user will not operate the change button 17a to change the first threshold data TH1 to the fourth threshold data TH4 (S701: NO), the threshold data change processing is terminated without going through the processing in S702 and S703.

[0134] Returning to Fig. 12, the description of the brightness setting process will be continued. Following the threshold data changing process (S505), a level data changing process is executed (S506). The level data changing process is a process for changing the first level data LV1 to the fourth level data LV4 used in the above-mentioned second LED brightness level setting process based on an operation by the user.

[0135] Here, threshold data change processing is executed (S506) with reference to Fig. 15. Fig. 15 is a flowchart showing the level data change processing executed by the CPU 201 of the fish detector 12 of this embodiment.

[0136] As shown in Fig. 15, the level data change process is executed as follows. First, the CPU 201 judges whether the user has operated the change button 17a to change the first level data LV1 to the fourth level data LV4 to be used (S801). As a result, if it is judged that the user has operated the change button 17a to change the first level data LV1 to the fourth level data LV4 (S801: YES), the CPU 201 reads out the level data set by the change button 17a (S802). Then, the CPU 201 stores the read out level data in the first level data LV1 to the fourth level data LV4 (S803) and ends the level data change process.

[0137] On the other hand, if it is determined as a result of the processing of S801 that the user will not operate the change button 17a to change the first level data LV1 to the fourth level data LV4 (S801: NO), the level data change processing is terminated without going through the processing of S802 and S803 described above.

[0138] Returning to Fig. 12, the luminance setting process will be described further. When the CPU 201 ends the level data change process (S506), the process returns to S501. Then, the process of S501 to S506 is repeatedly executed until the power supply of the fish finder 12 is turned off. When the first threshold data TH1 to the fourth threshold data TH4 and / or the first level data LV1 to the fourth level data LV4 are changed, the luminance level of the second LED 18 is determined by the process of S504 executed in the next loop based on the changed first threshold data TH1 to the fourth threshold data TH4 and / or the first level data LV1 to the fourth level data LV4.

[0139] In this way, in the threshold data change process, the first threshold data TH1 to the fourth threshold data TH4 are changed by the user operating the change button 17a, so that the luminance change point of the luminance level of the second LED 18 in response to the change of the knob position TL can be easily changed according to the user's preference.

[0140] In addition, in the level data change process, the first level data LV1 to the fourth level data LV4 are changed by the user operating the change button 17a, whereby the luminance level of the second LED 18 determined by the comparison between the knob position TL and the first threshold data TH1 to the fourth threshold data TH4 can be changed according to the user's preference.

[0141] The brightness level of the second LED 18 can be easily changed according to the user's preference because, rather than specifying the brightness level of the second LED 18 corresponding to the knob position TL in a brightness table, the brightness change points at which the brightness level of the second LED 18 changes in response to changes in the knob position TL are specified by the first threshold data TH1 to the fourth threshold data TH4, and the brightness level of the second LED 18 is specified by the first level data LV1 to the fourth level data LV4.

[0142] Moreover, by simply defining the luminance change points at which the luminance level of the second LED 18 changes with respect to the change in the knob position TL using the first threshold data TH1 to the fourth threshold data TH4 and defining the luminance level of the second LED 18 with the first level data LV1 to the fourth level data LV4, the luminance level of the second LED 18 can be changed to a desired luminance level in stages with respect to the change in the knob position TL, so that the required memory capacity can be reduced compared to the case where a luminance table that defines the luminance level of the second LED 18 corresponding to the knob position TL is used. Furthermore, compared to the case where the luminance level of the second LED 18 corresponding to the knob position TL is defined by a luminance table, the luminance level of the second LED 18 can be easily changed according to the user's preference.

[0143] (Fourth embodiment) Next, a schematic configuration of a fish finder 12 according to a fourth embodiment of the underwater detection device of the present invention will be described with reference to Figs. 16 to 18. In the first embodiment, the case was described in which the brightness levels of the second LED 18 are defined as significant brightness levels for all knob positions TL in all of the brightness tables A to C. In contrast, the fish finder 12 according to the fourth embodiment differs from the fish finder 12 according to the first embodiment in that it uses a brightness table F in which the brightness level of the second LED 18 is set to "0" when the knob position TL exceeds "200". Here, differences from the fish finder 12 according to the first embodiment will be described in detail, and common points will be denoted by the same reference numerals and their description will be omitted.

[0144] 16 is a block diagram showing the electrical configuration of the fish finder 12 of the fourth embodiment. In the fish finder 12 of the fourth embodiment, a brightness adjustment program 202f and a brightness table F are stored as data stored in the flash memory 202.

[0145] The brightness adjustment program 202f of this embodiment is a collection of a series of instructions executed by the CPU 201 to adjust the brightness levels of the first LED 16 and the second LED 18 in particular during the operation of the fish finder 12. The brightness adjustment program 202f also includes a program for the CPU 201 to execute the brightness setting process shown in Fig. 18.

[0146] The brightness table F is a table that associates the brightness levels of the first LED 16 and the second LED 18 determined according to the knob position TL of the power button 14. Details of the brightness table F will now be described with reference to Fig. 17. Fig. 17 is a diagram that diagrammatically illustrates the brightness table F stored in the flash memory 202 of the fish finder 12 of this embodiment.

[0147] 17, the brightness table F associates each value of the knob position TL that can be received from the AD converter 205 connected to the power button 14 with a corresponding brightness level of the first LED 16 and a corresponding brightness level of the second LED 18. The value of the knob position TL is an integer between "1" and "255".

[0148] The brightness table F sets the brightness level of the first LED 16 to the same value as the corresponding knob position TL. Meanwhile, the brightness level of the second LED 18 is set to "1" for knob position TL values ​​of "1" to "50", "2" for knob position TL values ​​of "51" to "100", "3" for knob position TL values ​​of "101" to "200", and "0" for knob position TL values ​​of "201" to "255".

[0149] Next, the operation of the fish finder 12 of the fourth embodiment configured as above will be described with reference to FIG. 18, focusing on the brightness setting process.

[0150] Fig. 18 is a flowchart showing the luminance setting process executed by the CPU 201 of the fish finder 12 of this embodiment. The fish finder 12 executes the luminance setting process as follows, as shown in the flowchart of Fig. 18, by the CPU 201 executing various calculations according to the luminance adjustment program 202f.

[0151] First, the CPU 201 stores the knob position TL received from the AD converter 205 connected to the power button 14 in the knob position received data 203a of the RAM 203 (S901). The knob position TL stored here is data indicating the rotation position of the operation button 17 for determining the luminance level of the first LED 16 and the luminance level of the second LED 18.

[0152] Next, the CPU 201 reads out the luminance level of the first LED 16 and the luminance level of the second LED 18 corresponding to the knob position TL from the luminance table F (S902). The CPU 201 outputs the read out luminance level of the first LED 16 to the first LED driver 207, and outputs the luminance level of the second LED 18 to the second LED driver 208 (S903). The first LED driver 207 converts the digital value of the luminance level of the first LED 16 output by the CPU 201 into an analog signal and outputs it to the first LED 16. The first LED 16 illuminates the display 15 with a luminance corresponding to the luminance level based on the analog signal of the luminance level. The second LED driver 208 converts the digital value of the luminance level of the second LED 18 output by the CPU 201 into an analog signal and outputs it to the second LED 18. The second LED 18 illuminates the operation button 17 and the like with a luminance corresponding to the luminance level based on the analog signal of the luminance level.

[0153] When the knob position TL exceeds 200, the CPU 201 outputs 0 to the DA converter (second LED driver 208) corresponding to the second LED 18, so that the second LED 18 does not emit light.

[0154] After the process of S903, the CPU 201 repeatedly executes the processes of S901 to S903 until the power supply of the fish detector 12 is turned off.

[0155] In this way, the fish finder 12 of the fourth embodiment uses a brightness table F in which the brightness level of the second LED 18 is set to "0" when the knob position TL exceeds "200". When the surroundings around the fish finder 12 are bright and the user wants to increase the brightness level of the display 15, it is often unnecessary to emit light from the operation buttons 17, etc. In such cases, by setting the brightness level of the second LED 18 in the brightness table F to "0" so that the corresponding second LED 18 does not emit light once the knob position TL reaches a certain value or higher, unnecessary emission of light from the second LED 18 that illuminates the operation buttons 17, etc. can be suppressed, resulting in energy savings.

[0156] Fifth embodiment Next, a schematic configuration of a fish finder 12 according to a fifth embodiment of the underwater detection device of the present invention will be described with reference to Figs. 19 to 22. In the first embodiment, a case was described in which a significant brightness level is set for the second LED 18 for any knob position TL based on each of the brightness tables A to C. In contrast, the fish finder 12 according to the fifth embodiment differs from the fish finder 12 according to the first embodiment in that when the knob position TL exceeds the fifth threshold data TH5 set by the user, the brightness level of the second LED 18 is set to "0" regardless of the brightness level of the second LED 18 stored in the brightness table G. Here, differences from the fish finder 12 according to the first embodiment will be described in detail, and common points will be denoted by the same reference numerals and their description will be omitted.

[0157] 19 is a block diagram showing the electrical configuration of the fish finder 12 of the fifth embodiment. In the fish finder 12 of the fifth embodiment, the data stored in the flash memory 202 include a brightness adjustment program 202g, a brightness table G, and a fifth threshold data TH5.

[0158] The brightness adjustment program 202g of this embodiment is a collection of a series of instructions executed by the CPU 201 to control the operation of the fish finder 12. The brightness adjustment program 202g also includes a program for the CPU 201 to execute the brightness setting process and the second LED turning off process shown in Figs. 21 and 22.

[0159] The brightness table G is a table that associates the brightness levels of the first LED 16 and the second LED 18 determined according to the knob position TL value of the power button 14. The configuration of the brightness table G is the same as that of the brightness table A used in the first embodiment, and therefore a description thereof will be omitted here.

[0160] The fifth threshold data TH5 is a threshold used in a second LED turning-off process described later, and when the knob position TL exceeds the fifth threshold data TH5, a process is performed to turn off the second LED 18. The value of the fifth threshold data TH5 is an integer between "1" and "255".

[0161] Next, the operation of the fish finder 12 of the fifth embodiment configured as above will be described with reference to FIG. 20, focusing on the luminance setting process.

[0162] Fig. 20 is a flowchart showing the luminance setting process executed by the CPU 201 of the fish finder 12 of this embodiment. The fish finder 12 executes the luminance setting process as follows, as shown in the flowchart of Fig. 21, by the CPU 201 executing various calculations according to the luminance adjustment program 202g.

[0163] First, the CPU 201 stores the knob position TL received from the AD converter 205 connected to the power button 14 in the knob position reception data 203a of the RAM 203 (S1001). The knob position TL stored here is data indicating the rotation position of the operation button 17 for determining the luminance level of the first LED 16 and the luminance level of the second LED 18.

[0164] Next, the CPU 201 reads out the luminance level of the first LED 16 and the luminance level of the second LED 18 corresponding to the knob position TL from the luminance table G (S1002). The CPU 201 outputs the read luminance level of the first LED 16 to the first LED driver 207 (S1003). The first LED driver 207 converts the digital value of the luminance level of the first LED 16 output by the CPU 201 into an analog signal and outputs it to the first LED 16. Based on the analog signal of the luminance level, the first LED 16 illuminates the display 15 with a luminance according to the luminance level.

[0165] Next, the second LED turning-off process is executed (S1004). The second LED turning-off process is a process for turning off the second LED 18 regardless of the setting value of the brightness table G when the knob position TL received from the power button 14 exceeds a predetermined threshold value.

[0166] The luminance change point reception process will now be described with reference to Fig. 21. Fig. 21 is a flow chart showing the second LED turning-off process executed by the CPU 201 of the fish finder 12 of this embodiment.

[0167] As shown in Fig. 21, the second LED turning off process is executed as follows. First, the CPU 201 judges whether the user has operated the change button 17a to change the fifth threshold data TH5 (S1101). As a result, if it is judged that the user has operated the change button 17a to change the fifth threshold data TH5 (S1101: YES), the CPU 201 reads out the threshold data set by the change button 17a (S1102). Then, the CPU 201 stores the read out threshold data as the fifth threshold data TH5 in the flash memory 202 (S1103), and proceeds to the process of S1104.

[0168] On the other hand, if it is determined as a result of the process of S1101 that the user will not operate the change button 17a to set the luminance change point shift amount R (S1101: NO), the processes of S1102 and S1103 are omitted and the process proceeds to S1104.

[0169] In the process of S1104, it is determined whether the value of the knob position TL is greater than the fifth threshold data TH5 (for example, "200") (S1104). As a result, if the value of the knob position TL is greater than the fifth threshold data TH5 (S1104: YES), the CPU 201 outputs "0" to the second LED driver 208 (S1106). In other words, the second LED 18 is prevented from emitting light, and the second LED turning-off process is terminated.

[0170] On the other hand, if the result of the determination in S1104 is that the value of the knob position TL is equal to or less than the fifth threshold data TH5 (S1104: NO), the CPU 201 outputs the brightness level of the second LED 18 read out in the process of S1002 to the second LED driver 208 (S1105). The second LED driver 208 converts the digital value of the brightness level of the second LED 18 output by the CPU 201 into an analog signal and outputs it to the second LED 18. Based on the analog signal of the brightness level, the second LED 18 illuminates the operation button 17 and the like with a brightness corresponding to the brightness level, and ends the second LED turning-off process. Returning to FIG. 20, the explanation of the brightness setting process will be continued. When the CPU 201 ends the second LED turning-off process (S1004), it returns to S1001. Then, the processes of S1001 to S1004 are repeatedly executed until the power supply of the fish finder 12 is turned off.

[0171] In this way, when the brightness level of the second LED 18 corresponding to the knob position TL exceeds a predetermined threshold, the second LED 18 can be turned off without relying on the brightness level value set in the brightness table F. This makes it possible to suppress unnecessary emission of light from the second LED 18 that illuminates the operation button 17 and the like when the surroundings of the fish finder 12 are bright, thereby enabling energy savings.

[0172] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and it can be easily assumed that various improvements and modifications are possible within the scope of the present invention. For example, each embodiment may be modified by adding a part or a plurality of parts of the configuration of each other embodiment to the embodiment, or by replacing a part or a plurality of parts of the configuration of the embodiment, including the modified examples described below. In addition, the numerical values ​​given in the above embodiments are merely examples, and other numerical values ​​can be naturally adopted.

[0173] In the fish finder 12 of each of the above embodiments, the power button 14 turns the power of the fish finder 12 on and off and adjusts the brightness level of the first LED 16 and the brightness level of the second LED 18, but the present invention is not limited to this, and a button for adjusting the brightness level of the first LED 16 and the brightness level of the second LED 18 may be provided separately from the power button 14. Also, the adjustment is performed by rotating a knob, but may also be performed by sliding. Also, the user may be allowed to input the degree of brightness of the first LED 16 by operating the operation button 17 or the like, and the brightness level of the first LED 16 and the brightness level of the second LED 18 may be set according to the degree of brightness.

[0174] In the fish finder 12 of each of the above embodiments, the brightness level of the first LED 16 is set to the same value as the knob position TL in all of the brightness tables A to G, but a value different from the knob position TL may be set. Also, the brightness level of the first LED 16 does not have to be proportional to the knob position TL, and as long as it increases monotonically, the way in which it changes may be arbitrary. Also, the number of brightness tables stored in the fish finder 12 may be arbitrary.

[0175] In the fish finder 12 of the third embodiment described above, the second LED luminance level setting process is performed using the first threshold data TH1 to the fourth threshold data TH4 as the threshold data, but this is not limited to this, and the number of threshold data may be arbitrary.

[0176] In the fish finder 12 of the third embodiment, the values ​​of the first level data LV1 to the fourth level data LV4 are defined as integers from "1" to "15", but are not limited thereto. A fifth level data LV5 may be provided so that a value larger than the fourth level data LV4 or "0" can be set. If the value of the fifth level data LV5 is set to "0", the second LED 18 does not emit light when the knob position TL>the fourth threshold data TH4. If the value of the fifth level data LV5 is other than "0", the luminance level of the second LED 18 is set to the value indicated by the fifth level data LV5. Furthermore, only the fifth level data LV5 may be set by the user within the range of "0" to "15" or the range of "1" to "15". This allows the user to respond to both cases where the user desires strong brightness as the light emitted from the second LED 18 when the knob position TL>the fourth threshold data TH4, and where the user desires weak light (or no light emission) as the light emitted from the second LED 18. In addition, in the third embodiment, the first level data LV1 to the fourth level data LV4 are changed by the user within a range where the relationship of the first level data LV1<the second level data LV2<the third level data LV3<the fourth level data LV4 is maintained, but regardless of such a relationship, any of the first level data LV1 to the fourth level data LV4 may be freely changed by the user within a range of "0" to "15" or "1" to "15". This allows the brightness level of the light emitted from the second LED 18 at each stage of the knob position TL to be set more in accordance with the user's preference.

[0177] The fish finder 12 according to the fourth embodiment uses a brightness table in which the brightness level of the second LED 18 is set to "0" when the knob position TL exceeds "200", but a brightness table in which the brightness level of the second LED 18 is set to "1" when the knob position TL exceeds "200" may be used. That is, in this case, even when the surroundings around the fish finder 12 are bright and the user wants to increase the brightness level of the display 15, the light emission of the corresponding second LED 18 can be kept dark, resulting in energy savings.

[0178] In the fish finder 12 according to the fifth embodiment, the brightness level of the second LED 18 is set to "0" without reference to the brightness table G when the knob position TL exceeds the fifth threshold data TH5. However, in this case, the brightness level of the second LED 18 may be set to, for example, "1" without reference to the brightness table G. That is, in this case, even when the surroundings around the fish finder 12 are bright and the user wants to increase the brightness level of the display 15, the light emission of the corresponding second LED 18 can be kept dark, resulting in energy savings.

[0179] In the fish finder 12 of the fourth and fifth embodiments described above, when the brightness level of the second LED 18 in the brightness table F is “0”, the brightness level is output to the second LED driver 208. However, when the brightness level of the second LED 18 is “0”, a signal for preventing the second LED 18 from emitting light may be output to the second LED driver 208 in addition to the brightness level.

[0180] In each of the above embodiments, the underwater detection device has been described using a fish finder 12 as an example, but the device is not limited to this as long as it uses sound waves to detect underwater, and also includes a tidal current meter that uses ultrasound to measure and display the speed of the current at each depth, a plotter that shows the depth contours of the water bottom measured based on the reflected ultrasound waves from the bottom of the water, and a device that identifies and displays the bottom sediment based on the intensity of the reflected ultrasound waves from the bottom of the water.

[0181] In addition, the descriptions in parentheses in the [Explanation of Symbols] column may clearly indicate the correspondence between the terms used in each of the above embodiments and the terms used in the claims. [Explanation of symbols]

[0182] 11 Ships 12 Fish finder (underwater finder) 13 Main unit 14 Power button (brightness reception area, designated area) 15 Display (display area) 16 1st LED 17 Operation button (operation part, designated area) 17a Change button (operation part) 18 Second LED (light emitting part) 19 Pilot lamp (specified area) 20 Transducers 200 Control section 201 CPU 202 Flash Memory 202a, 202c, 202e, 202f, 202g Brightness adjustment program (first brightness adjustment unit, second brightness adjustment unit) 202b Luminance table type data used 202d Luminance change point setting data 203 RAM 203a Knob position reception data 204 I / O ports 205 A / D converter 206 VRAM 207 1st LED driver (DA converter) 208 Second LED driver (DA converter) 209 Transmitting Circuit 210 Receiving circuit

Claims

1. A transducer capable of transmitting ultrasonic waves underwater and receiving the reflected waves; a display area for displaying an image generated based on a reception signal generated when the transducer receives a reflected wave of the ultrasonic wave transmitted from the transducer; a light-emitting unit that emits a predetermined amount of light in a predetermined area different from the display area; a brightness receiving unit that receives, from a user, a brightness level of light emitted from the display area; a control unit that adjusts the luminance of the light emitted from the display area and the luminance of the light emitted from the predetermined area based on the degree of the luminance received by the luminance receiving unit; Equipped with The control unit is a first brightness adjustment unit that adjusts the brightness of the light emitted from the display region so as to change substantially continuously in response to a change in the degree of the brightness received by the brightness reception unit; a second brightness adjustment unit that adjusts the brightness of the light emitted from the predetermined region so as to change stepwise in response to a change in the degree of the brightness received by the brightness reception unit; An underwater detection device comprising:

2. a storage unit that stores a luminance table that predetermines luminance levels of light emitted from the display region and luminance levels of light emitted from the predetermined region corresponding to the respective degrees of luminance received by the luminance receiving unit, the first luminance adjustment unit adjusts a luminance level of the light emitted from the display region to a luminance level corresponding to the degree of luminance accepted by the luminance acceptance unit, with reference to the luminance table in the storage unit; The underwater detection device described in claim 1, characterized in that the second brightness adjustment unit adjusts the brightness level of the light emitted from the specified area to a brightness level corresponding to the degree of brightness accepted by the brightness accepting unit by referring to the brightness table in the memory unit.

3. The underwater detection device according to claim 2, characterized in that the control unit is provided with a change unit that changes the brightness table referenced by the first brightness adjustment unit and / or the second brightness adjustment unit based on instructions from a user.

4. the storage unit stores a plurality of luminance tables in which at least one of a luminance level of light emitted from the display region corresponding to each of the luminance degrees received by the luminance receiving unit and a luminance level of light emitted from the predetermined region corresponding to each of the luminance degrees received by the luminance receiving unit is different, The underwater detection device according to claim 3, characterized in that the change unit selects a brightness table to be referenced by the first brightness adjustment unit and / or the second brightness adjustment unit from among the plurality of brightness tables based on instructions from a user.

5. The underwater detection device described in claim 1, further comprising a brightness change point receiving unit that receives from a user a change in the brightness change point of light emitted from the specified area, which changes gradually through adjustment by the second brightness adjustment unit, in response to the change in the degree of brightness received by the brightness receiving unit.

6. The underwater detection device described in claim 1, characterized in that the second brightness adjustment unit adjusts the brightness so that light having a predetermined brightness is emitted from the specified area when the degree of brightness accepted by the brightness accepting unit is below a predetermined threshold, and prevents light from being emitted from the specified area when the degree of brightness accepted by the brightness accepting unit exceeds a predetermined threshold.

7. The underwater detection device according to claim 1 , characterized in that the brightness receiving section has a knob section that, when rotated by a user, receives the degree of brightness of the light emitted from the display area based on the amount of rotation.

8. 8. The underwater detection device according to claim 7, wherein the knob portion also serves as a power switch.

9. an operation unit provided in the predetermined area and configured to receive instructions related to the operation of the underwater detection device by a user; 9. The underwater detection device according to claim 1, wherein the light emitting section emits a predetermined amount of light toward the operation section.

Images