JP3013977U - Helical antenna and small transmitter using the antenna - Google Patents

Abstract

(57) [Abstract] [Purpose] A helical antenna that can make the radio output omnidirectional and can secure a desired radio wave communication distance in spite of its small size, and a compact and portable transmitter using the helical antenna. I will provide a. [Structure] The rod-shaped high-frequency ferrite core 3a is wrapped in, for example, a shrinkable insulating tube and heated to form an insulating film 3c on the ferrite core. Thereafter, the coated copper wire 3b is wound around the ferrite core in a coil shape or a helical shape to form a helical antenna. One end of the conductor 3b of the helical antenna is electrically connected to the antenna terminal of the transmission circuit housed in the main body case to form a small transmitter.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a helical antenna and a small transmitter using the antenna, and particularly to a small transmitter and a small transmitter suitable for use in an elderly person / person with disabilities emergency call system, an automatic health abnormality report system, etc. About the helical antenna.

[0002]

[Prior art]

 Elderly people and people with physical disabilities who are living alone should take prompt and appropriate measures when their health condition deteriorates or when an emergency such as an accident, theft, or fire occurs, because they are elderly, physically and mentally weak, or physically disabled. It cannot be taken and can have disastrous consequences. If an elderly person or a physically handicapped person can contact the outside in the event of such an emergency, the unfortunate situation can be prevented. For this reason, in recent years, a comprehensive emergency reporting system that can deal with unfortunate situations has been researched, developed, and put into practical use as a core project of national welfare policy. In such a system, a small pendant type transmitter, which is convenient for carrying around at all times, is carried by an elderly person or a physically handicapped person, and a signal is transmitted from this transmitter when an emergency occurs. In the house of the elderly or the physically handicapped, a dedicated wireless receiver and a dedicated reporting device connected to the general subscriber telephone line are installed, and the wireless receiver transmits signals sent from the elderly and the physically disabled. Upon receipt, a dedicated notification device will notify the emergency measures center, which is ready to accept calls 24 hours a day, to indicate an emergency. At the emergency center, the receptionist immediately requests the dispatch of an ambulance, and also informs the pre-promised service workers, welfare institutions, hospitals, fire departments, police stations, etc. near the reporter of the emergency. , These persons call the caller and try to solve the emergency.

As shown in FIG. 11, the pendant type small transmitter used in the system as described above has the pendant main body (small transmitter) 2 fixed to both ends of the antenna-combined suspension cord 101, as shown in FIG. The pendant main body 102 is hung on the neck so as to be carried around. However, in such a small pendant type transmitter, the length of the hanging string 101 used as an antenna becomes considerably long depending on the wavelength of the radio wave used. For this reason, the pendant body attached to the end of the hanging string that hangs from the neck swings, making it difficult to carry out daily work.In addition, when washing or cooking, a small transmitter is submerged in water, which causes malfunction. There is a possibility. In addition, in the conventional small pendant type transmitter, the antenna string is in close contact with the human body at the shoulder and chest, and the radio waves are absorbed by the human body, resulting in poor transmission efficiency.

Therefore, as shown in FIG. 12, a suspending cord 103 is formed by connecting the insulating cord 103 a and the quarter-wavelength antenna cord 103 b, and the insulating cord 103 a is provided on the transmitter main body 104. A portable small-sized oscillator has been proposed in which the antenna string 103b hangs downward from the main body when the main body 104 is suspended by movably inserting it into the through hole (Japanese Utility Model Publication No. 3-28607). In this small transmitter, since the insulating cord 103a is movably inserted into the transmitter main body 104, the position of the transmitter main body 104 can be adjusted in the vertical direction like a cord tie. Unlike the small pendant type transmitter, the transmitter body does not dangle at the end of the cord, making it easy to carry, and it will not hinder your daily work or life. Moreover, since the antenna string portion is configured to hang down from the transmitter body, the antenna string does not come into close contact with the human body unlike the small pendent type transmitter of FIG. 11, and is supported straight. A quarter wavelength equivalent length can be secured and transmission efficiency can be improved.

[0005]

[Problems to be solved by the device]

 The small-sized transmitter of FIG. 12 has many advantages as described above and is therefore widely used in emergency reporting systems. However, since the antenna string 103b or the insulating string 103a having a length corresponding to a quarter wavelength hangs down from the transmitter main body 104, there is a problem in that the string blunts and becomes an obstacle.

In view of the above, the object of the present invention is to provide a small transmitter which has an omnidirectional characteristic and is convenient for carrying without the antenna part getting in the way, and a helical antenna suitable for being applied to the small transmitter. It is to be. Another object of the present invention is a small-sized transmitter capable of reliably transmitting a transmitter signal to a receiver installed in a substantially central part of a house from a small house or any place in a general house. And to provide a suitable helical antenna applied to the small transmitter.

[0007]

[Means for Solving the Problems]

 According to the present invention, the above-mentioned problem is solved by a rod-shaped high frequency ferrite core, a conductor wire wound around the ferrite core in a coil shape or a helical shape, and one end of which is connected to the high frequency circuit, and between the ferrite core and the conductor wire. It is achieved by a helical antenna provided with an insulating material for insulation and a small transmitter using the antenna.

[0008]

[Action]

 An insulating film is formed on the ferrite core by wrapping the rod-shaped high-frequency ferrite core in a shrinkable insulating tube and heating it. Then, the coated copper wire is wound around the ferrite core in a coil shape or a helical shape to form a helical antenna. One end of the copper wire of such a helical antenna is electrically connected to the antenna terminal of the transmitting circuit housed in the main body case to form a small transmitter.

According to the above-mentioned helical antenna, the wireless output can be made non-directional, and the communication distance can be secured more than that of the conventional string antenna despite the fact that the line is extremely thin and thin. A compact transmitter that uses this helical antenna is convenient for carrying because the antenna part does not interfere, and the transmitter signal can be installed almost anywhere in the house from almost any location. It can be surely transmitted to a receiver that has been set up, and is suitable for use in an emergency reporting system for the elderly living alone and the physically handicapped, an automatic reporting system for health abnormalities, etc.

[0010]

【Example】

 (a) Appearance of the small transmitter of the present invention Fig. 1 is an external view of the small transmitter of the present invention, (a) is a top view, (b) is a front view, (c) is a bottom view, and (d). Is a side view and (e) is a rear view. Reference numeral 1 denotes a case main body for accommodating a printed circuit board (not shown) on which a transmission circuit is mounted, which can be separated into a front case 1a and a rear case 1b. 2 is a waterproof rubber packing for tightly adhering between the front case and the back case, 3 is a helical antenna, and 4 and 5 are ears provided on both sides of the main body case 1, respectively, through holes. 4a and 5a are formed. 6 is an LED that informs the owner that the small transmitter is in an operable state, and turns off when the built-in battery voltage drops. Reference numeral 7 denotes a reset button for resetting the built-in transmission circuit to the initial state, which is in the recess so that it cannot be operated carelessly. Reference numeral 8 is a rubber push button, which the holder presses in the event of an emergency, and 9 is a cap that covers the screws that fix the front and back cases.

(B) Configuration of Antenna As shown in FIG. 2, the helical antenna 3 includes a rod-shaped high frequency ferrite core 3a and a coil or a helical shape wound around the ferrite core, and one end of which is a small transmitter. It includes a covered conductor 3b connected to the transmitter circuit and an insulating portion 3c for insulating between the ferrite core and the conductor. The insulating part 3c is formed by wrapping the ferrite core 3a in an insulating (polyoffrene or the like) shrink tube and shrinking the tube by heating. As for the antenna dimensions, the length of the ferrite core is about 26 mm and the outer diameter is about 3. It is 8mm straight, very thin and short. According to such a helical antenna, as will be described later, the wireless output is omnidirectional, and the communication distance is greater than that of the conventional string antenna.

(C) Internal Structure of Case FIG. 3 is an explanatory view when the surface case 1a is removed from the case body 1, and the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals. 1b is a back case, 3 is an antenna, 4'and 5'have a semi-cylindrical shape, and constitutes corresponding parts of the front case 1a and ears 4, 5 (see FIG. 1) (hereinafter referred to as ears). , 11 are printed circuit boards on which a transmission circuit is mounted. A groove 1b-2 for guiding the conducting wire 3b of the antenna 3 to the inside is formed in the side wall 1b-1 of the rear case 1b, and a hole for guiding a hanging string (described later) to the inside of the ear through hole is provided. Back holes 1b-3 and 1b-4 are formed. The ears of the surface case 1a have the same structure (there are no ears back holes), and the through holes 4a and 5a (FIG. 1) are formed by superposing them. Reference numeral 5b is a receiving portion for receiving the antenna, and holds the antenna 3 so as not to easily separate from the case body. Further, 4a 'and 5a' are depressions, so that the rounded end portions of the clip described later fit.

(D) Transmission Circuit The transmission circuit formed on the printed circuit board 11 includes a transmission section 11a, a switch 11b that is closed and closed when the push button 8 (see FIG. 1B) is operated, and a timer 11c. An LED driver 11d for driving the LED 6 (FIG. 1), a reset circuit 11e, a battery 11f for supplying a voltage to each part, a battery voltage detection part 11g, and a microcomputer 11h for controlling the entire transmission circuit are provided. The wiring pattern 11i connected to the antenna terminal of the transmitter 11a is electrically connected to the conductor wire 3b of the helical antenna 3 by solder 11j or the like. The transmitter 11a has a built-in oscillator having an oscillation frequency of 137.2 MHz, and transmits a high frequency signal modulated by the data instructed by the microcomputer 11h from the helical antenna 3.

(E) Transmission Characteristics of Helical Antenna of the Present Invention FIG. 4 is an explanatory diagram of transmission characteristics (antenna directivity performance) of the helical antenna of the present invention, in which transmission power (dBμV / m) is measured in the radial direction. The rotation angle is attached to the direction. As apparent from this characteristic diagram, according to the present invention the helical antenna, the maximum transmission power is 46.43dBμV / m (39 ⁰ direction), substantially circular omnidirectional performance. FIG. 5 is a return loss characteristic diagram of the helical antenna of the present invention, and FIG. 6 is a phase characteristic diagram. As is clear from FIG. 5, the maximum return loss is a low loss of −22.862 dB, and as is clear from FIG. 6, the maximum phase deviation is as small as 64.281 ^0, and there is no problem in practical use.

The following table is a performance comparison table of other antennas and the helical antenna of the present invention.

[Table 1] According to the helical antenna of the present invention, since the low-loss high-frequency ferrite is used in the core of the entire coil, the shape for frequency tuning can be made extremely small and small. It is also understood from the table that the antenna characteristics are extremely good, and that the communication distance and power consumption are greatly improved by improving the shape and mounting method. In other words, the helical antenna of the present invention can be constructed to be as small as a built-in antenna, and the case body can be made light, thin, short, and small, and the performance equivalent to that of a whipped type omnidirectional antenna can be obtained. The power consumption is extremely good, and there is no deterioration in performance even if the case body is metalized (titanium, gold foil, etc.).

(F) Operation of Transmission Circuit When the push button 8 is pushed down, the switch 11b is turned on. The microcomputer 11h sends switch-on data to the transmitter 11a when the switch is turned on, and the transmitter 11a transmits a high frequency signal modulated by the data from the helical antenna 3. When a dedicated radio receiver installed in the house receives a signal transmitted from an elderly person or a physically handicapped person, it controls the dedicated notification device to notify the emergency countermeasure center, which is ready for 24-hour reception, of an emergency. According to the small transmitter of the present invention, the signal from the transmitter can be sent to the receiver installed in the center of the house from any place of the general house (wooden 2nd floor, building area 30 tsubo, site area 60 tsubo). Is sure to be transmitted. Further, the microcomputer 11h monitors the time data from the timer 11c, and sends the time signal data to the transmitter 11a once a month (730H) or once a day (24H), and the transmitter 11a sends the data. The helical antenna 3 radiates a high frequency signal modulated by. The dedicated whistleblower installed in the house constantly monitors whether or not the scheduled signal is received, and if it does not receive it, it reports to the Emergency Response Center. As a result, it is possible to promptly detect a stowage in a small transmitter, an abnormality in the transmitter, or an abnormality in the receiver, and automatically notify the emergency center to take prompt action.

When the power supply voltage of the built-in battery 11f drops, the communication distance becomes shorter, and even if the push button 8 is pushed down in an emergency, the high frequency signal may not be able to reach the receiver. For example, when the battery voltage under no load is 2.5 V or less (normally 3 V), the communication distance of radio waves becomes short and it becomes impossible to report an emergency. In this case, since the LED 6 is still lit even when the battery voltage is 2.5 V or less, the owner does not notice the dead battery, which causes a serious situation. Therefore, the small transmitter is equipped with a function for monitoring battery shortage and reporting. By the way, if the battery voltage is detected to be 2.5V or less when there is no load and the battery is exhausted, it cannot be reported because the radio wave communication distance has already become short. Therefore, the microcomputer 11h receives from the battery voltage detection unit 11g the power supply voltage (load voltage) when transmitting the switch-on signal or the timed signal from the transmission unit 11a, and when the load voltage is 2.5V or less, the dead battery data is output. Is sent to the transmission unit 11a, and the battery exhaustion signal is transmitted from the transmission unit. By doing this, the battery voltage during transmission will be reduced by about 0.3V compared to when there is no load, so it is possible to reliably detect and notify the dead battery before the no-load voltage drops below 2.5V. . The LED 6 is turned off at the same time that the battery is dead. Further, the transmitter 11a is adapted to repeatedly transmit various signals five times in response to an instruction from the microcomputer 11h. In this case, if the transmission and the lighting of the LED are performed at the same time, the peak value of the consumption current becomes large and the battery consumption is accelerated. Therefore, the microcomputer 11h controls the LED to be turned off when transmitting a signal and turned on when not transmitting. That is, radio wave emission and LED lighting are alternately performed to reduce the peak value of current consumption.

(G) Portable Structure of Small Transmitter-Portable by Clip FIG. 7 is an explanatory view of a clip and a clip attachment for making the small transmitter of the present invention portable, and the same parts as those in FIG. Attached. Figure 7 (a) is a front view of the clip, (b) is a side view of the clip attached to the case body (antenna not shown), and (c) is a rear view of the clip attached to the case body. (d) is a front view when the clip is attached to the case body. In the figure, reference numeral 41 designates a plastic clip, which has a clip body 41a having a spring property in which a restoring force acts in the A and B directions, and through holes 4a of ears 4, 5 of the case body provided on both sides thereof. 5a (see FIG. 1) is provided with round bar-shaped locking portions 41b and 41c. At the time of attachment, the clip 41 is attached to the main body case 1 by narrowing the locking portions 41b and 41c slightly inward and inserting them into the through holes 4a and 5a of the ears 4 and 5. In this state, the main body 41a of the clip 41 is inserted into the collar, chest pocket, waist belt, etc. of the clothes to make the small transmitter portable. In this case, since the spring force acts on the clip 41 in the A direction, the clip 41 does not easily come off from the case body 1.

FIG. 8 is another structural explanatory view of the clip 41. The difference from the clip of FIG. 7 is that the rounded portions 41b ′ and 41c ′ are formed at the tips of the locking portions 41b and 41c. By forming the rounded portions 41b 'and 41c', it is possible to prevent the clip 41 from easily coming off the main body case 1. That is, when the clip 41 is attached to the case body, the rounded portions 41b 'and 41c' are fitted into the recesses 4a 'and 5a' (Fig. 3) provided in the through holes 4a and 5a. As a result, the clip 41 does not easily come off from the case body 1. -Portable by a hanging string Fig. 9 is an explanatory view of attaching the hanging string, (a) is a state diagram in which the hanging string 51 is attached to the case body, and (b) is an installation diagram of the hanging string 51. is there. The hanging string 51 is formed by guiding one end of the hanging string 51 to the back of the ear part through the through holes 4a and 5a and the back holes 1b-3 and 1b-4 of the ear part and forming a retaining member 51a at the end of the string. Can be attached to Case 1. When carrying, hang the hanging string around your neck.

(H) Configuration of Push Button FIG. 10 is an explanatory diagram of a rubber push button. As shown in FIG. 10 (a), the push button 8 is formed by integrally forming a key portion 8a having a collar portion and a seat portion 8b, and fixing the seat portion 8b by the back surface of the front case 1a and the pressing plate 8c. It is configured. When the key portion 8a is pushed down, the protrusion 8d provided on the bottom surface of the key portion closes the switch 11b (FIG. 3) provided on the printed board 11. The operation surface of the key portion 8a and the surface of the front case 1a are configured to have substantially the same height. In addition, a gap 8e is provided between the periphery of the key portion 8a and the surface of the case, so that the cap (protruding push button adapter) 61 can be covered with the key portion 8a and engaged and fixed to the brim portion. (Fig. 10 (b)). In this case, the cap 61 is attached so as to project from the surface of the surface case 1a and is removable. 10 (c) is a state in which the cap 61 is removed, and FIG. 10 (d) is a state in which the cap 61 is attached. When the small transmitter is to be carried by an elderly person or a physically handicapped person, the cap 61 is attached and the small case is projected from the surface of the surface case 1a. As a result, an elderly person or a physically handicapped person can easily push down the push button 8 with his / her palm or arm to report an emergency situation. Also, when carrying a healthy person, the push button 8 can be prevented from being inadvertently pushed down by removing the cap.

(I) Fields of Application of the Small Transmitter of the Present Invention The application of the small transmitter of the present invention to an emergency call system for persons with physical disabilities and an automatic health abnormality notification system has been described above. The transmitter can be applied not only to such a system but also to various systems because of the advantage that no wiring is required. For example, it can be applied to a factory single worker emergency call system, an automatic fire detector addition device, a crime prevention sensor addition device, a wireless caller, a housing equipment monitoring addition device, a control remote controller, and the like.

The factory single worker emergency notification system is used when one operator is working in a computer control room or one operator is working in an unmanned factory. Or it is a system that reports the occurrence of other emergencies. When the fire detector detects a fire, the automatic fire detector add-on device automatically turns on the switch to notify the receiver of the fire from the transmitter. The security sensor add-on device has an opening / closing sensor installed on the window or entrance door, etc., and when the window or door is opened in the monitoring state, the switch is automatically turned on to prevent the intruder from entering the receiver from the transmitter. It is something to report. The radio caller is carried by a cashier at a supermarket or a window teller at a bank, etc., and when a danger arises, the switch is turned on to report. The additional equipment for housing equipment monitoring is used to report an abnormality when a sensor that detects water supply interruption, gas leakage, or electric leakage detects these, and the control remote control is used to open or close the doors of automobiles or houses. The above is the case where the small transmitter is provided with a push button, but the push button is not always necessary depending on the application system. For example, the push button is not always necessary when applied to an automatic fire detector addition device, a crime prevention sensor addition device, and a housing equipment monitoring addition device. Although the present invention has been described with reference to the embodiments, the present invention can be modified in various ways according to the gist of the present invention as set forth in the claims, and the present invention does not exclude them.

[0023]

[Effect of device]

 As described above, according to the present invention, since a helical antenna is formed by winding a wire around a rod-shaped low-loss high-frequency ferrite core in a coil shape or a helical shape, it is possible to make the wireless output omnidirectional, and to produce a linear ultrathin short compact Nevertheless, it is possible to secure the communication distance and low power consumption that are superior to those of the conventional string antenna. In addition, since such a helical antenna is adopted for a small transmitter, the small transmitter is convenient for carrying because the antenna part does not get in the way, and the signal of the transmitter can be sent from any place in a general house. It can be reliably transmitted to the receiver installed in the center of the center, and is suitable for use in an emergency notification system for elderly people living alone or for physically handicapped people, an automatic notification system for health abnormalities, etc.

[Brief description of drawings]

FIG. 1 is an external view of a small transmitter of the present invention.

FIG. 2 is a schematic diagram of a helical antenna of the present invention.

FIG. 3 is an explanatory view of a small transmitter of the present invention.

FIG. 4 is a diagram showing an antenna directivity characteristic of the present invention.

FIG. 5 is a return loss characteristic diagram of the helical antenna of the present invention.

FIG. 6 is a phase characteristic diagram of the helical antenna of the present invention.

FIG. 7 is an explanatory diagram of a clip and clip attachment.

FIG. 8 is an explanatory diagram of another configuration and attachment of the clip.

FIG. 9 is an explanatory view of attaching a hanging string.

FIG. 10 is an explanatory diagram of a push button configuration.

FIG. 11 is an explanatory diagram of a conventional small transmitter.

FIG. 12 is another explanatory diagram of a conventional small transmitter.

[Explanation of symbols]

 1 ・ ・ Main body case 1a ・ ・ Front case 1b ・ ・ Back case 3 ・ ・ Helical antenna 3a ・ ・ Ferrite core 3b ・ ・ Conductor wire 3c ・ ・ Insulation part (insulation tube)

Claims (2)

[Scope of utility model registration request] 1. A rod-shaped high frequency ferrite core, a conductor wire having one end wound around the ferrite core in a coil shape or a helical shape and connected to a high frequency circuit, and an insulating portion for insulating between the ferrite core and the conductor wire. A helical antenna characterized by that. 2. A body case for accommodating a transmission circuit, a rod-shaped high-frequency ferrite core, a wire whose one end wound around the ferrite core in a coil shape or a helical shape is connected to the transmission circuit, a ferrite core and a wire. And a helical antenna having an insulating portion for insulating between the
A small transmitter characterized in that one end of a conducting wire is electrically connected to an antenna terminal of a transmitting circuit.