JPH03223614A - Apparatus for measuring length of thread for fishing reel - Google Patents

Abstract

PURPOSE:To realize an apparatus for measuring the length of thread for a small, light fishing reel which can be applied to reels for various kinds of sizes by transmitting an ultrasonic wave beam to the surface of the bobbin diameter of a spool, and computing and displaying the length of the thread based on the obtained bobbin-diameter signal and the counted value of an up/down counter. CONSTITUTION:A bobbin-diameter detecting device 6 is connected to an input interface 12 through a transmitting circuit 23 and a receiving circuit 27. An ultrasonic wave beam 21 is transmitted to the surface of the bobbin diameter of a spool 2 from the bobbin-diameter detecting device 6. The time difference between the transmission and the reception of a reflected wave 25 which is reflected from the surface of the bobbin diameter is measured. Thus the bobbin diameter is measured. When the spool 2 is rotated in the forward rotating direction in accordance with the unreeling of thread fishing thread 3, the signal in the forward direction is received with a CPU 9 from a sensor 15 through the input interface 12. Then, the length of the thread is operated based on the counted content of an up/down counter 16 and the data corresponding to the diameter of bobbin diameter outputted from the bobbin- diameter detecting device 6. The the length of the unreeled thread is displayed on a display device 5 through an output interface 13.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a fishing reel line length measuring device, more specifically, it is a fishing reel line length measuring device, and more specifically, it is capable of measuring with high accuracy the amount of fishing line being fed out and the amount of reeling based on the rotational speed of the spool. The present invention relates to a yarn length measuring device.

[Conventional technology]

With modern fishing reels, the length of the fishing line from the spool (7) is measured, and the length of the reel is measured to accurately lower the tackle to the shelf where the fish are, or for cast fishing, measure the flight distance of the tackle. You can check the point where the device was introduced.

Conventionally, the methods for measuring the amount of fishing line being fed out and retracted are as follows:
For example, as shown in Japanese Unexamined Patent Publication No. 60-244247, data such as the relational expression between the winding amount and the spool winding diameter, the total length of the thread, etc., and the thread thickness as a parameter are sent to a microcomputer built into the reel body. It is input from the keyboard, and when measuring the yarn length, the rotation of the spool is detected by a sensor, the pulse ft from this sensor is counted by a counter, and this counted value is taken into the microcomputer at every calculation cycle. By selecting a yarn length calculation formula according to the yarn diameter to be used, calculating the yarn length based on the calculation formula, and outputting the calculation result to the display, the yarn length for feeding or winding can be displayed on the display. The information was displayed digitally for the benefit of anglers.

However, with the conventional line length measuring device for a fishing reel as described above, each time the line used changes, the line thickness data and the total length data of the line wound on the spool must be entered using a keyboard. The input operation is complicated, and the line length calculation formula is a quadratic or cubic formula, so it takes a long time to calculate the line length on a microcomputer with low computing power, which makes it difficult to cast. When the yarn payout speed is fast, the yarn length calculation speed cannot keep up with the yarn payout speed, and the yarn length, which changes from moment to moment, cannot be displayed immediately. Furthermore, if the yarn length calculation formula is simplified, there is a problem that accurate yarn length measurement becomes impossible.

Therefore, the present applicant first developed a fishing reel line length measuring device that solved this problem, and filed a patent application for this in 1983.
No. 137764 was filed as a line length measuring device for a fishing reel.

The fishing reel line length measuring device according to this application includes a reel body, a spool rotatably supported by the reel body and around which a fishing line is wound, a sensor for detecting the rotation of the spool, and a sensor for detecting the rotation of the spool. an up/down counter that counts up and down a pulse signal output from the spool; a light emitting unit that irradiates a spot light onto the surface of the bobbin diameter of the spool; and a position sensor that detects the position of the reflected light reflected from the surface of the bobbin diameter. a bobbin diameter calculating means for detecting the detected bobbin diameter and converting it into an electric signal proportional to the bobbin diameter, and a means for calculating the thread length based on the bobbin diameter data from the bobbin diameter calculating means and the counted value of the up/down counter. , and a display for displaying the yarn length calculated by this calculation means.

In this fishing reel line length measuring device, when the light emitting means illuminates the bobbin diameter surface of the spool, the position of the spot reflected light is detected by the position sensor of the bobbin diameter calculation means, and a signal proportional to the bobbin diameter is detected. Therefore, if the yarn length is calculated by a calculation means based on this bobbin winding diameter signal and the rotational speed corresponding to the rotational speed at the time of yarn payout or winding counted by the up/down counter, the yarn length to be paid out and The length of the wound yarn can be determined quickly and with high accuracy, and parameters such as the thickness of the yarn and the total length of the yarn are not required when measuring the yarn length, improving the operability of the reel.

[Problem to be solved by the invention]

However, in the line length measuring device for a fishing reel as described above, since a spot light is irradiated onto the surface of the diameter of the spool, the light beam output from the light emitting body such as an LED or a semiconductor laser element is There is a problem in that it is necessary to focus the reflected light onto the pincushion surface using an optical system such as a lens, and it is also necessary to focus the reflected light on the position sensor using another optical system.

That is, when using the optical system as described above, it is very difficult to downsize the sensor section because of the optical system.

Further, since the range of the thread diameter that can be measured by the negative optical system is limited, there is a problem in that the optical system needs to be changed depending on the size of the reel.

The present invention solves the above-mentioned problems, and aims to provide a fishing reel line length measuring device that is small and lightweight and can be applied to reels of various sizes.

[Means to solve the problem]

The fishing reel line length measuring device according to claim 1 includes a reel body, a spool rotatably supported by the reel body and around which a fishing line is wound, a sensor for detecting rotation of the spool, and a sensor for detecting rotation of the spool. an up/down counter that counts up and down the output pulse signal; a measuring means that measures the bobbin diameter by emitting an ultrasonic beam to the bobbin diameter surface of the spool; and bobbin diameter data from the measuring means. and a count value of the up/down counter, and a display for displaying the yarn length calculated by the calculation means.

In the fishing reel line length measuring device according to claim 2, in claim 1, the measuring means includes a transmitting means for emitting an ultrasonic beam to the surface of the thread diameter of the spool, and an ultrasonic beam reflected from the surface of the thread diameter of the spool. a receiving means for receiving waves, a timing means for measuring the time until the ultrasonic beam emitted from the transmitting means is received by the receiving means, and an electric current proportional to the diameter of the bobbin. and a bobbin diameter calculation means for converting into a signal.

In the fishing reel line length measuring device according to claim 3, according to claim 1, the measuring means applies a frequency-modulated transmission wave voltage to the ultrasonic sensor and emits an ultrasonic beam onto the surface of the thread diameter of the spool. A transmitting means for emitting a wave, a receiving means for receiving a received wave voltage induced in the ultrasonic sensor by a reflected wave reflected from the surface of the pincushion diameter, and a voltage obtained by mixing the transmitted wave voltage and the received wave voltage. A distance measuring means for determining the distance between the ultrasonic sensor and the bobbin diameter from the frequency of the beat signal, and a bobbin diameter calculating means for calculating bobbin diameter data indicating the size of the bobbin diameter from the distance found by the distance measuring means. It has the following.

[For production]

In the fishing reel line length measuring device of claim 1, the ultrasonic beam is emitted from the transmitting means to the thread diameter surface of the spool to measure the thread diameter, and the thread length counted by the thread diameter signal and the up/down counter is measured. The yarn length is calculated by the calculating means based on the rotation ratio or the rotation speed corresponding to the rotation speed during winding.

In the fishing reel line length measuring device according to claim 2, an ultrasonic beam is emitted from the transmitting means to the thread diameter surface of the spool,
The reflected wave is received by the receiving means, and the time measuring means measures the time until the ultrasonic beam emitted from the transmitting means is received by the receiving means.

Then, the time measured by the timer is converted into an electrical signal proportional to the diameter of the bobbin by the bobbin diameter calculation means, and this bobbin diameter signal and the bobbin winding ratio or rotational speed at the time of winding are counted by the up/down counter. The yarn length is calculated by the calculation means based on the rotational speed corresponding to .

In the fishing reel line length measuring device of claim 3, the transmission means applies a frequency-modulated transmission wave voltage to the ultrasonic sensor, and the ultrasonic beam is transmitted from the ultrasonic sensor to the surface of the thread diameter of the spool. On the other hand, a received wave voltage induced in the ultrasonic sensor by the reflected wave reflected from the surface of this pincushion diameter is received by the receiving means.

Then, the distance measuring means mixes the received wave voltage received by the receiving means and the transmitted wave voltage, and the distance between the ultrasonic sensor and the pincushion diameter is determined from the frequency of the beat signal obtained by this mixing. The spool diameter calculating means calculates spool diameter data indicating the size of the spool diameter from the distance determined by the distance measuring means.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

1 and 2 show an embodiment of the present invention. In FIG. 2, ■ is a reel body, and 2 is a reel body 1.
A fishing line 3 is wound around this spool 2.

Reference numeral 4 denotes a waterproof flat box integrally attached to the upper surface of the reel main body 1, and the upper surface panel 4a of this box 4 is provided with a display 5 and a bobbin diameter detecting device 6.

Furthermore, a microcomputer for calculating the yarn length, a battery (both of which will be described later), and the like are watertightly housed in the box 4. 7 is a handle for winding and rotating the spool 2.

In FIG. 1, numeral 8 indicates a microprocessor that performs yarn length calculation, yarn length display, and data writing control.

The microprocessor 8 is connected to a CPU (central processing unit) 9 that controls and manages program memory, data memory, timers, and input/output devices and executes calculations and transfer processes necessary to process a given job. ROM10 and CPU that store the length calculation processing program and yarn length calculation formula
RAM II that stores data such as calculation results in 9, input interface I2, and output interface 13
These are connected to the CPU' 9 via a bus 14.

A sensor 15 detects the rotation and direction of the spool 2, and is composed of a pair of reed switches 15a15b and a plurality of magnets 15c fixed to the inner periphery of the spool 2 in opposition to the reed switches 15a15b.

Then, the reed switches 15a and 15b are connected to the magnet 1.
The spool forward/reverse rotation determination signal obtained by turning 0N10FF first by 5c is input to the CPU 9 through the input interface 12 to set the built-in up/down counter 16 to an up-count or down-count state. It has become.

Further, by inputting the rotation pulse of the spool 2 obtained by turning the reed switches 15a and 15b ON to 10FF to the up/down counter 16 through the input interface 12, the 1 counter is made to count up or down.

Furthermore, the bobbin diameter detection device 6 is connected to the input interface 12 via a transmitting circuit 17a and a receiving circuit 17b.

A digital display 5 for displaying yarn length is connected to the output interface 13 via a decoder 18, and
A pincushion diameter detection device 6 is connected.

The bobbin diameter detection device 6 includes an ultrasonic sensor 19 that emits an ultrasonic beam 21 to the bobbin diameter surface of the spool 2 and receives a reflected wave 25 reflected from the bobbin diameter surface.

This ultrasonic sensor 19 has an external shape as shown in FIG. 3, for example, and has a waterproof structure, and as shown in FIG. It is configured by connecting.

In the figure, reference numeral 196 indicates an acoustic matching layer, and reference numeral 19 indicates an acoustic matching layer.
7 is a metal case, code 198 is a base, code 199
indicates a sealing material.

FIG. 1 also shows details of the control means of the bobbin detection device 6, which includes a transmitting circuit 23 for emitting an ultrasonic beam 21 onto the surface of the bobbin diameter of the spool 2, and and a receiving circuit 27 that receives the reflected wave 25 of the ultrasonic beam 21 reflected from the surface P of the diameter, and the ultrasonic beam 21 emitted from the transmitting circuit 23 is transmitted to the receiving circuit 27.
The timer 29 built into the microprocessor 8 is configured to measure the time difference until the data is received by the microprocessor 8. Then, this time difference Δt and the distance d to the pincushion surface stored in the ROM10 = (sound speed 331 (m/s
e c) d is calculated from the formula x2/IXΔL.

FIG. 5 shows an example of the transmitting circuit 23 and the receiving circuit 22, in which a signal instructing the trigger terminal 20 to perform measurement is sent from the CPU.
When input from 9, transistor 22 turns on and a pulse
A high-voltage pulse signal from the transformer 24 is applied to the ultrasonic sensor 19 by the number of waves of the CPU 9. The ultrasonic beam 21 is reflected by the surface P of the pincushion diameter, becomes a reflected wave 25, enters the ultrasonic sensor 19 again, and induces a received wave voltage. The received wave voltage enters the receiving circuit 27, passes through a multi-stage amplification circuit,
After passing through the detection transformer 28, the signal is output from the detector terminal 30 to the input interface 12 of the microprocessor 8. The timer 29 starts with a signal from the CPU 9 instructing measurement, and ends with a signal from the detector terminal 30. This time difference Δt is stored in RAM II and used to calculate the distance ad.

FIG. 6 shows an example of time difference measurement. Ultrasonic sensor 19
For example, once every 1/4 rotation of the spool for 30 μs.
The transmission voltage waveform 35 is applied to the ultrasonic sensor 1 for a time of
9, an ultrasonic beam 21 is applied to the surface of the bobbin diameter of the spool 2.
fire. The reflected wave 25 reflected from the surface Pt of the pincushion diameter enters the ultrasonic sensor 19, and a voltage is induced. This voltage is amplified by the receiving circuit 27 and output as a received pulse 25. The time difference from the rising edge of the transmitting pulse to the rising edge of the receiving pulse is stored in the RAM 11 as a time difference ΔL of 181 μs.

That is, as shown in Fig. 1, the distance d from the ultrasonic sensor 19 to the diameter of the bobbin can be found as d = ΔtX (V/2), where the speed of sound is V, so by measuring the time Δt, It becomes possible to obtain d.

Figure 7 is a plot of the measured relationship between the sensor output voltage appearing at the detector terminal 30 in Figure 5 and the distance from the sensor surface to the surface of the bobbin diameter when the reel unwinds the line and performs seven winding operations. This is what I did. The distance 1i1d and the sensor output voltage have a linear relationship.

Then, the CPU 9 determines the thread diameter, and calculates the thread length as will be described later.

In addition, as shown in FIG. 1, if the distance between the ultrasonic sensor 19 and the rotation axis 37 of the spool 20 is C, the diameter of the bobbin can be easily determined by D-(c-d)X2. .

Next, the yarn length measuring operation of this embodiment configured as described above will be explained according to the processing procedure shown in FIG.

When the program shown in FIG. 8 starts, first, in step SIO, it is determined whether the fishing line 3 is let out.

Here, if it is determined that the fishing line 3 is being fed out, the spool 2 is rotated in the forward rotation direction as the fishing line 3 is being fed out, so a signal in the forward rotation direction is input from the sensor 15 to the CPU 9 through the input interface 12. As a result, the up/down counter 16 is set in the up direction, and the pulse signal for each rotation of the spool output from the sensor 15 as the spool 2 rotates is input to the up/down counter 16 through the input interface 12. are sequentially counted up (step 51).
1).

In the next step S12, the count contents N of the amplifier/down counter 16 are loaded into the CPU 9 every calculation cycle of the microcomputer 8, and the voltage corresponding to the pincushion diameter output from the pincushion diameter calculating means 31 is inputted into the CPU 9. The data converted into digital data by the converter is imported (step 512).
), in the next step 313, the calculation of L=π・D−N is executed, and the calculation result is outputted to the digital display 5 through the output interface 13 and the decoder 18, and the length of the unreeled fishing line 3 is digitally displayed. (Step 514).

On the other hand, if it is determined in step SIO that the fishing line 3 is being wound up, the spool 2 is rotated in the reverse direction as the fishing line 3 is wound, and therefore a signal in the reverse direction is sent from the sensor 15 to the input interface. CPU through 12
9, which causes the up/down counter I
6 is set in the down direction, the pulse signal output from the sensor 15 as the spool 2 rotates in the opposite direction is captured by the up/down counter 16, and is subtracted from the count during feeding by the down-counting operation (step 315). ).

Then, in the next step S16, the count contents Na of the up/down counter 16 are taken into the CPU 9 every calculation cycle of the microcomputer 8, and the winding yarn length is calculated by calculating La=π・D−Na. The yarn length La is calculated by subtracting the winding yarn length from the unreeled yarn length, and this is output to the digital display 5 to digitally display the yarn length La (step 517).

In the fishing reel line length measuring device configured as described above, the fishing reel line length measuring device is comprised of a reel body 1 and a fishing line 3 rotatably supported by the reel body 1. A spool 2 wound with
a down counter, a transmitting means 23 for emitting an ultrasonic beam 21 onto the surface of the bobbin diameter of the spool 2, a receiving means 27 for receiving the reflected wave 25 reflected from the surface of the bobbin diameter, and a beam emitted from the transmitting means 23. a clocking means 29 for measuring the time until the received ultrasonic beam 21 is received by the receiving means 27; and a bobbin diameter calculating means 31 for converting the time measured by the clocking means 29 into an electrical signal proportional to the bobbin diameter. and,
It is composed of means for calculating the yarn length based on the bobbin diameter data from the bobbin diameter calculation means 31 and the count value of the up/down counter, and a display 5 for displaying the yarn length calculated by this calculation means. Therefore, it becomes possible to easily provide a small and lightweight fishing reel line length measuring device that can be applied to reels of various sizes.

That is, in the fishing reel line length measuring device configured as described above, since the ultrasonic sensor 19 is used to measure distance, an optical system such as a lens is not required, so the sensor section can be downsized. becomes very easy.

Further, since the - ultrasonic sensor 19 can reliably measure over short to long distances, the same ultrasonic sensor can be used for reels of various sizes.

FIG. 9 shows a reel according to another embodiment of the present invention,
In this embodiment, a pincushion diameter detection device 6b is arranged below the thumb rest 6a.

FIG. 10 shows a fishing reel line length measuring device according to still another embodiment of the present invention. The measuring means for measuring the diameter of the bobbin spool is mainly composed of a transmitting means 33, a receiving means 35, a distance measuring means, and a spool diameter calculating means.

That is, the transmitting means 33 transmits the frequency-modulated transmitting wave voltage 4I to the ultrasonic sensor 1 as shown in FIG.
9 to emit an ultrasonic beam 21 onto the surface P of the thread diameter of the spool 2.

The receiving means 35 receives a received wave voltage 4 induced in the ultrasonic sensor 19 by the reflected wave 25 reflected from the surface P of the pincushion diameter.
Receive 2.

The distance measuring means determines the distance d between the ultrasonic sensor 19 and the pincushion diameter from the beat frequency f of the beat signal 43 obtained by mixing the transmitted wave voltage 41 and the received wave voltage 42.

That is, the beat frequency f of the beat signal has a linear relationship with the distance d as shown in the formula below and FIG. 12, so by measuring the beat frequency f1,
The distance d can be measured accurately.

f,=4d−f,−Δf/v Here, f indicates the modulation frequency, Δf indicates the modulation frequency band, and ■ indicates the speed of sound (331 m/sec).

Note that the above-mentioned received wave voltage 42 to be mixed includes:
The signal amplified to a predetermined value by a multi-stage amplifier circuit arranged in the receiving circuit of the receiving means 35 is used.

The spool diameter calculation means calculates spool diameter data indicating the size of the spool diameter from the distance determined by the distance measuring means.

In the fishing reel line length measuring device configured as described above, the measuring means applies a frequency-modulated transmission wave voltage 41 to the ultrasonic sensor 19, and measures the surface P of the thread diameter of the spool 2.
a transmitting means 33 for emitting the ultrasonic beam 21 at the spool, a receiving means 35 for receiving the received wave voltage 42 induced in the ultrasonic sensor 19 by the reflected wave 25 reflected from the surface P of the pincushion diameter, and the transmitted wave voltage 41 The beat frequency f of the beat signal 43 obtained by mixing the received wave voltage 42 and the received wave voltage 42.

a distance measuring means for calculating the distance d between the ultrasonic sensor 19 and the bobbin diameter from the distance, and a bobbin diameter calculating means for calculating bobbin diameter data indicating the size of the bobbin diameter from the distance found by the distance measuring means. As configured, the transmission means 33 applies the frequency-modulated transmission wave voltage 41 to the ultrasonic sensor 19, and the ultrasonic beam 21 is emitted from the ultrasonic sensor 19 to the surface P of the pincushion diameter of the spool 2. , the received wave voltage 42 induced in the ultrasonic sensor 19 by the reflected wave 25 reflected from the surface P of this pincushion diameter is received by the receiving means 35, and the received wave voltage 42 is received by the receiving means 35 by the distance measuring means. The wave voltage 41 and the transmission wave voltage 42 are mixed, and the beat signal 4 obtained by this mixing is
3 beat frequency f.

The distance d between the ultrasonic sensor 19 and the bobbin diameter is determined from the distance d, and the bobbin diameter calculation means calculates bobbin diameter data indicating the size of the bobbin diameter from the distance found by the distance measuring means. .

That is, in the fishing reel line length measuring device configured as described above, the transmitted wave voltage 41 and the received wave voltage 42 are mixed, and the beat signal 4 generated by this mixing is
Since the distance ld is measured based on the beat frequency f of 3, it is possible to obtain the same effect as the embodiment shown in FIG. This makes it possible to accurately measure shorter distances with smaller reels.

〔Effect of the invention〕

As described above, in the fishing reel line length measuring device of claim 1, the ultrasonic beam is emitted from the transmitting means to the bobbin diameter surface of the spool to measure the bobbin diameter, and the bobbin diameter signal and up/down The yarn length is calculated by a calculation means based on the number of rotations counted by a counter, which corresponds to the number of rotations for yarn reeling or winding. This makes it possible to easily provide a small and lightweight fishing reel line length measuring device that can be applied to reels of various sizes.

In the fishing reel line length measuring device according to claim 2, an ultrasonic beam is emitted from the transmitting means to the thread diameter surface of the spool,
The reflected wave is received by the receiving means, and the timer measures the time until the ultrasonic beam emitted from the transmitting means is received by the receiving means, so that the diameter of the bobbin can be easily and accurately determined. I can do it.

In the fishing reel line length measuring device of claim 3, the transmission means applies a frequency-modulated transmission wave voltage to the ultrasonic sensor, and the ultrasonic beam is transmitted from the ultrasonic sensor to the surface of the thread diameter of the spool. On the other hand, the received wave voltage induced in the ultrasonic sensor by the reflected wave reflected from the surface of this pincushion diameter is received by the receiving means, and the distance measuring means
The received wave voltage received by the receiving means and the transmitted wave voltage are mixed, the distance between the ultrasonic sensor and the bobbin diameter is determined from the frequency of the beat signal obtained by this mixing, and the bobbin diameter calculating means calculates the distance between the ultrasonic sensor and the bobbin diameter. Since the bobbin diameter data indicating the size of the bobbin diameter is calculated from the distance determined by the distance measuring means, the advantage is that the distance between the ultrasonic sensor and the surface of the bobbin diameter can be determined more accurately. be.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a yarn length measuring device in an embodiment of the present invention. FIG. 2 is a perspective view of a fishing reel equipped with the line length measuring device of this embodiment. FIG. 3 is a perspective view showing the ultrasonic sensor of FIG. 1. FIG. 4 is a longitudinal sectional view of FIG. 3. FIG. 5 is a transmitting/receiving circuit diagram of the bobbin diameter detecting device in this embodiment. FIG. 6 is an explanatory diagram showing the relationship between transmission and reception of ultrasound beams in this embodiment. FIG. 7 is a graph showing the relationship between distance and sensor output voltage. FIG. 8 is a flowchart showing the procedure for yarn length measurement and display in this embodiment. FIG. 9 is a perspective view showing a reel according to another embodiment of the present invention. FIG. 10 is an overall configuration diagram of a yarn length measuring device in still another embodiment of the present invention. FIG. 11 is an explanatory diagram for explaining the beat frequency in the embodiment of FIG. 10. FIG. 12 is a graph showing the relationship between distance and beat frequency. [Explanation of symbols of main parts] 1... Reel body 2... Spool 3... Fishing line 5... Digital display 6... Bottle diameter detection device 7... Handle 8... Micro Computer 9...CPU 15...Rotation detection sensor 16...Up/down counter 19...Ultrasonic sensor 21...Ultrasonic beam 23.33...Transmission means 25...Reflected wave 27 .35...Receiving means 29...Timekeeping means 31...Pitch diameter calculating means 41...Transmission wave voltage 42...Reception wave voltage 43...Beat signal fr...Beat frequency. Figure 3 Figure Figure 0 0U u -1fr- [IJ, Sl Figure 11

Claims (3)

[Claims] (1) A reel body, a spool that is rotatably supported by the reel body and has a fishing line wound around it, a sensor that detects the rotation of this spool, and an up-counter that counts up and down the pulse signal output from this sensor. / a down counter, a measuring means for measuring the bobbin diameter by emitting an ultrasonic beam to the surface of the bobbin diameter of the spool, and based on the bobbin diameter data from the measuring means and the counted value of the up/down counter. 1. A fishing reel line length measuring device comprising: means for calculating the line length; and a display for displaying the line length calculated by the calculating means. (2) The measuring means includes a transmitting means for emitting an ultrasonic beam onto the surface of the bobbin diameter of the spool, a receiving means for receiving a reflected wave reflected from the surface of the bobbin diameter, and an ultrasonic wave emitted from the transmitting means. A claim characterized by comprising: a timer for measuring the time until the beam is received by the receiver; and a bobbin diameter detecting means for converting the time measured by the timer into an electrical signal proportional to the bobbin diameter. Item 1. A fishing reel line length measuring device according to item 1. (3) The measuring means includes a transmitting means that applies a frequency-modulated transmission wave voltage to an ultrasonic sensor to emit an ultrasonic beam onto the surface of the thread diameter of the spool, and a reflected wave reflected from the surface of the thread diameter of the spool. a receiving means for receiving the received wave voltage induced in the ultrasonic sensor by the ultrasonic sensor, and a distance between the ultrasonic sensor and the pincushion diameter from the frequency of the beat signal obtained by mixing the transmitted wave voltage and the received wave voltage. A fishing reel according to claim 1, characterized in that it has a distance measuring means to be determined, and a spool diameter calculating means for calculating spool diameter data indicating the size of the spool diameter from the distance determined by the distance measuring means. Yarn length measuring device.