JP3502992B2 - TV antenna - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television antenna used for receiving all of VHF low-band and high-band television signals and UHF television signals. 2. Description of the Related Art An element having a length of 1/4 of a low-band wavelength of VHF is connected to a feeding point, and one element of a high-band wavelength of VHF from the feeding point is connected to the element. /
A stub for VHF is provided at point 4 and a stub for UHF is provided at point の of the wavelength of UHF (see, for example, JP-A-1-181305). Such an antenna is relatively small in overall length, which is about 1/4 of the wavelength of the VHF low band, and at the feed point, not only the VHF low band but also the stub attached As a result, it resonates with the VHF high band and UHF, so that those television signals can be received. [0003] However, in the above-mentioned conventional television antenna, in the case of receiving a VHF high band and UHF television signal, each of the above elements has a stub attached from the feeding point to a quarter. Only the portion up to the wavelength point receives the respective radio waves, and the other portions do not receive any radio waves.Therefore, the reception gain of those television signals is low. There was a problem limited to the area. The present invention has been made to solve the above-mentioned problems (technical problems) of the prior art, and receives the VHF high band and UHF television signals at a high gain by using the entire antenna element. It is an object of the present invention to provide a television antenna which can be used. [0005] To achieve the above object, a television antenna according to the present invention has a first feeding point and a second feeding point. Connects a first element having a length 7/8 times the wavelength of a UHF television signal and connects the first element to the first element.
At a point 1/4 times the wavelength from the feeding point of
An extension coil is provided to make the electrical length of the element 1/4 times the wavelength of the VHF low-band television signal, and a first extension coil for passing the UHF television signal is provided to the extension coil. A capacitor is connected in parallel, while one end of a second element is connected to the second feeding point, and the other end of the second element is connected via a second capacitor for passing a UHF television signal. The first element is connected to an intermediate portion between the extension coil and the element tip, and the length from the second feeding point to the tip of the first element via the second element is the above-mentioned length. It is configured to be 7/8 times the wavelength of the UHF television signal, and the second capacitor is connected to the first feeding point from the second feeding point.
The electrical length up to the tip of the element is selected to be a value that makes it 1/4 times the wavelength of the VHF high band television signal. The first element resonates with an extension coil having an electric length of 1/4 wavelength with respect to the VHF low band, so that the first element functions as a VHF low band antenna and operates as a UHF low band antenna. For 、 wavelength and 5 /
It acts as a two-stage antenna with eight wavelengths. On the other hand, the portion from the second feeding point to the tip of the first element via the second element has an electrical length of 1/4 wavelength with respect to the high band of VHF due to the second capacitor. To resonate,
In addition to acting as an antenna for the high band of VHF, it acts as an antenna having a length of 7/8 times the wavelength of UHF for UHF. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a usage state of an automobile antenna.
Reference numeral 1 denotes an automobile, and 2 denotes an automobile antenna attached to a rain gutter as an example. It may be installed on the trunk. 2 to 4 showing the antenna 2 in detail will be described.
The antenna 2 is used to make it easy to attach and detach
It is composed of two elements, a base 3 attached to the vehicle and an antenna body 4 detachable from the base 3. First, the base 3 will be described. Reference numeral 5 denotes a well-known mounting tool for mounting to a vehicle, and 6 denotes a base body, both of which can make the base body 6 straight even when the mounting state of the mounting tool 5 to the vehicle is inclined. The pivotal attachment 7 is pivotally attached with, for example, a screw rod. The attachment 5 is formed by, for example, pressing a sheet metal. Reference numeral 8 denotes an attachment portion for a rain gutter or a trunk lid of an automobile. Reference numeral 9 denotes a connecting piece with the base body 6. FIG. 4 shows the base body 6 in detail.
5 and 7 will be described. The base body 6 is composed of a lower first element 11 and an upper second element 12 each formed of an insulating hard molding material, for example, a plastic material. And a connector 14 such as a screw. Reference numeral 16 denotes a receiving groove provided on the upper surface of the base 3 and is recessed in the second element 12. The receiving groove 16 has an opening at one side 17 for inserting the insertion strip of the antenna body 4 from the side. 18 is receiving groove 16
Are convex locking strips for preventing the antenna body 4 from being lifted up on both side surfaces of the antenna. Reference numeral 20 denotes a locking claw provided on the bottom surface of the receiving groove 16, which is provided so as to be freely protruded and retracted from a through hole 21 provided on the bottom surface. FIG. 8 shows a configuration in which the locking claw 20 can freely move in and out.
As shown in the figure, for example, a guided portion 22 formed integrally with the locking claw 20 is slidably held up and down by a guide cylinder 23, and the locking claw 20 itself is also guided up and down by a hole edge of the through hole 21. It is. Reference numeral 24 denotes an urging member for urging the locking claw 20 in the protruding direction. As an example, a conical coil spring is used. In order to prevent the locking claw 20 from jumping out, the hole edge of the through hole 21 is used as a stopper, and the engaging portion 25 provided on the locking claw 20 is engaged therewith. Reference numeral 26 denotes a guide surface for operating the locking claw 20 by inserting a later-described insertion strip, and is formed on a slope facing the open end 17 of the receiving groove 16. Reference numeral 27 denotes a linking piece for linking with a release mechanism 30 described below, which is formed integrally with the locking claw 20. The position of the locking claw 20 is such that when the insertion strip 51 is inserted into the receiving groove 16 as described later, the locking claw by the insertion strip 51 in a state where the insertion is sufficiently performed. It is located in the back so that 20 immersion operations can be performed. The inner part is defined as an insertion part when the immersion operation of the locking claw 20 is started.
Reference numeral 51 denotes a depth at which the insertion is performed to such a depth that the straightness can be maintained, for example, a portion which is about half or more of the depth of the receiving groove 16 in the insertion direction. The locking claw 20 may be provided on the inner surface of the receiving groove 16 so as to be freely protruded and retracted. Next, FIG. 10 showing the release mechanism 30 will be described. 7 and 8, illustration of a release mechanism is omitted in order to prevent congestion in the figures. Reference numeral 31 denotes a release member which is movable in the lateral direction of the figure by being guided by, for example, guide portions 32 and 33. Numeral 34 denotes a pressing portion, which is formed on a slope as shown in the drawing and faces the connecting piece 27. Reference numeral 35 denotes a missing portion for allowing the connecting piece 27 to freely move up and down. Reference numeral 36 denotes a release operation button attached to the release body 31. Next, receiving terminals 37 and 38 shown in FIG. 5 for receiving a received signal from the antenna body 4 are shown in FIG.
It is straddled on the seat 39 like. 40 is one end of the receiving terminal 3
The other end is connected to the receiver inside the car by the feeder line connected to 7, 38. Next, FIG. 2 showing the antenna main body 4 will be described. The antenna main body 4 is composed of an antenna base 43 and an antenna tip 44. The former 44a can be attached to the upper part 43a of the former, and the antenna tip 44 can be attached to the side surface of the antenna base 43. It is foldably connected in two folds. The length L1 of the antenna base 43 is equal to the antenna tip 44.
Is formed to a length substantially corresponding to the length L2. For example, each of the lengths L1 and L2 has a large effect of shortening the antenna main body 4 by folding in two, and in the folded state, the weak antenna tip 44 has a strong overall length of the antenna base.
In order to be protected by 43, L1 is set to be substantially equal in length to the extent that L1 is slightly larger than L2. Above antenna base
43 is formed in a box shape so as to have a strong structure.
(B), the four circumferential walls 47 to 50 are provided at the antenna tip.
It is more robust than 44. For this purpose, it is possible to adopt a method of using a hard material as the constituent material of the wall surface or increasing the thickness. The antenna base 43 is formed by joining, for example, two elements as indicated by reference numerals 45 and 46. The constituent materials of these elements are formed of a material that transmits radio waves, for example, a plastic material, for the purpose of incorporating a member for receiving radio waves, as described later. Next, FIGS. 4, 6 and 7 showing the configuration of the lower part of the antenna body 4 will be described. Reference numeral 51 denotes an insertion strip provided at the lower end of the antenna main body 4, and has a sectional shape corresponding to the sectional shape of the receiving groove 16 so that insertion into the receiving groove 16 from the open end 17 is possible. Numerals 52 are engagement grooves formed on both outer side surfaces of the insertion strip 51 so as to correspond to the locking strips 18. The relationship between the locking ridge 18 and the engaging groove 52 is relative, and it is possible to provide an engaging groove on both inner surfaces of the receiving groove 16 and to provide a locking ridge on both outer surfaces of the insertion member 51. good. 53 is a locking claw for engagement with the locking claw 20.
An engagement recess formed on the lower surface of the insertion strip 51 corresponding to the position 20. When the locking claw 20 is provided on the inner surface of the receiving groove 16,
The recess 53 is also provided on the outer surface of the insertion strip 51. 54 and 55 are first and second feed points provided at the bottom of the antenna body 4, respectively.
For connection with the receiving terminals 37 and 38, a part of each of them is exposed to the lower surface of the antenna body 4 to form connection terminals 54a and 55a. Next, FIG. 2 showing the configuration of the antenna tip 44 will be described. The antenna tip 44 is formed in a thin line shape in order to reduce the wind resistance when the automobile is running. Reference numeral 57 denotes a base material for holding the element body 58.
The element body 58 is mechanically as thin as a plate-shaped element while the shape remains electrically narrow, so that the reception bandwidth is expanded.
The two element pieces 59 are arranged in parallel. The tips of both element pieces 59 are connected to each other by a connecting body 65 made of an insulating material for mechanical integration. The element piece 59 is configured, for example, as shown in FIG. 14 so as to have flexibility. Numeral 60 is a linear conductor that acts electrically as a receiving element, and is, for example, a thin conductive wire so that it can bend freely while maintaining flexibility and the electrical length does not change even in the bent state. The periphery of the core 62 configured as described above (a plurality of bundles may be bundled as shown or a single configuration may be used)
It is surrounded by a coil body 63 made of a conductive thin wire. 64 is a coating material for improving weather resistance, for example, polyethylene. Next, FIGS. 11 to 13 showing a connecting portion between the antenna base 43 and the antenna tip 44 will be described. This portion is configured as follows so that both can be bent while maintaining the electrical connection between them. Base material of the pivot 67 and the antenna tip 44 provided above the antenna base 43
The arm parts 68 and 69 provided on the pivot 57 are pivotally connected with bolts 70 exemplified as pivot attachments. The tip of the bolt 70 is the arm
It is screwed with a nut member 71 (for example, an insert) provided in 69. 72 is a wave washer. Reference numeral 74 denotes a current-carrying member provided on the inner surface of the arm 69, and is formed of, for example, a metal material having good conductivity. Reference numeral 75 denotes a connector for electrically connecting the current-carrying member 74 and the linear conductor 60 of the element piece 59, and is integrally formed with the current-carrying member 74. 76 is an empty space on the arm 69 side of the pivot 67
Another energizing member located at 67a
A stop piece 76a formed integrally is fixed to a stop 67b provided on the pivot 67 for holding there. Reference numeral 77 denotes a connection terminal for connecting an element element described later. 78
Is a pressing member that presses the current-carrying member 76 against the current-carrying member 74 for electrical connection between them, for example, a coil spring is used. With such a configuration, the antenna tip 44 is freely bendable with respect to the antenna base 43 around the pivotal attachment 70,
In addition, in any bent state, the current-carrying member 76 is pressed against the current-carrying member 74, and a good electrical conduction state is maintained between them. The corrugated uneven tooth profile 98 provided on the conductive member 76 and the corrugated uneven tooth profile 99 provided on the conductive member 74 mesh with each other by being pressed by the pressing member 78. When the antenna tip 44 is adjusted in the direction of arrow 97 in FIG. 2, the tooth shape 99 slides sideways while engaging and disengaging from the tooth shape 98, and the energizing member 74 rotates with respect to the energizing member 76.
The rotation of the antenna tip portion 44 with respect to 43 gives a step-like feel (click feeling). When adjustment is completed, tooth profile 98, 99
Engage with each other, and hold the position of the antenna tip portion 44 so as not to be inadvertently lowered with respect to the antenna base portion 43. Next, FIG. 15 shows the structure of a member that performs an electrical function as an antenna in the above-mentioned automobile antenna 2.
Will be described. Reference numeral 81 denotes a first element element, which is formed of a conductive wire, for example, a normal coated copper wire, and has one end connected to the first feeding point 54 and the other end connected to the connection terminal 77, respectively. 82 is an extension coil 83 and U for the low band of VHF
A parallel resonance circuit comprising a first capacitor 84 for passing an HF television signal.
It is interposed at four places. Reference numeral 85 denotes a second element element, one end of which is connected to the second feeding point 55 and the other end of which is connected to the connection terminal 77 via a second capacitor 86 for passing a UHF television signal. The second capacitor 86 electrically shortens the wavelength of the high frequency band of VHF, and is also called a shortening capacitor. Next, FIG. 16 shows the electrical structure of the above-mentioned antenna 2 for a vehicle. Reference numeral 91 denotes a first element, which is composed of the first element 81 and the linear conductor 60 in the element piece 59. The length of the extension coil 83 extends from the feeding point 54.
As described above, the length L3 is one of the wavelengths of the UHF.
/ 4 times, and the entire length L4 of the portion beyond that is 5/8 times the wavelength of UHF, and the overall length L5 is 7/8 times the wavelength. L3 is 110m in actual size
The total length L5 including m, L3 and L4 is 400 mm. The value of the extension coil 83 is selected so as to make the electrical length of the first element 91 substantially １ ／ times the low-band wavelength of VHF. Reference numeral 92 denotes a second element.
The element element 82 of FIG. The length L6 from the second feeding point 55 to the tip 91a of the first element 91 via the second element 92 is set to 7/8 times the wavelength of the UHF, and the value of the shortening capacitor 86 Indicates that the electrical length of the above-mentioned length L6 is approximately 1/1 / the wavelength of the high band of VHF.
The value to be quadrupled is selected. In the first element 91, the length L7 from the first feeding point 54 to the intermediate portions 74 and 76 where the second element 92 is connected via the capacitor 86 is, for example, slightly longer than half of the length L5. It is 220 mm long.
The position of the intermediate portion is determined due to the two-fold configuration of the antenna base 43 and the antenna tip 44, and is closer to the extension coil 83 than the above position for the electric function as an antenna. The position may be set to the position on the side closer to the tip or the position closer to the tip 91a. In the above configuration, during use as shown in FIG. 1, VHF low-band and high-band television signals and UHF television signals received by the above-described elements are transmitted from the connection terminals 54a and 54b. It is provided to receiving terminals 37 and 38 and is drawn into a receiver in a vehicle through a power supply line 40. In the receiver, of the signals arriving from the receiving terminals 37 and 38, those having good strength or good quality are appropriately selected as is known from diversity antennas and used for television reception. In this case, it is preferable to move the antenna tip 44 up and down as indicated by the arrow 97 in FIG. 2 so as to increase the sensitivity. When the car is washed by a car washer or parked on the road, the antenna body 4 is detached from the base 3 to prevent damage or theft. When the operation buttons 36 on both sides are pushed in as shown in FIG. 10B, the connecting piece 27 is pushed down by the pushing portion 34 of the release body 31, so that the locking claw 20 is inserted into the through hole 21 as shown in the figure. Then, the engagement with the engagement concave portion 53 is released. In this state, the antenna body 4 is moved with the other hand by the arrow in FIG.
If it is moved in the 95 direction, the insertion strip 51 comes out of the receiving groove 16 and the antenna main body 4 can be separated from the base 3. The antenna main body 4 thus removed can be folded in two as shown in FIG. 17 to reduce its size, and can be put in, for example, a pocket 96 of a jacket so as not to be in the way. In this case, as is clear from FIGS. 17 and 18, the linear and weak antenna tip 44 is in a state of being close to the box-shaped and durable antenna base 43, so that the element piece 59 of the antenna tip 44 is large. Even if it is bent as shown by a broken line in FIG. 17 due to an external force, it is only deformed within a range in which it can be elastically restored to a state in which it comes into contact with the antenna base 43, and further large deformation is prevented, leading to breakage. To prevent that. Next, when the antenna body 4 is to be reattached to the base 3, first, as shown in FIG.
The front end 51 a of the 51 is addressed to the open end 17 of the receiving groove 16, and the engaging groove 52 is positioned on the extension of the locking strip 18. In this case, as shown in the figure, the tip 51a is placed on the bottom surface 16a of the receiving groove 16, and using the fulcrum as a fulcrum to position the engaging groove 52 on the extension of the locking strip 18, the operation is easy. . Next, the antenna main body 4 is advanced with respect to the base 3 as shown by an arrow in FIG. 9B, and the insertion strip 51 is inserted into the receiving groove 16. When the insertion is deep enough, the insertion
The leading end 51 a of the 51 reaches the locking claw 20. Even so, the insertion operation is continued as it is. Then, the locking claw 20 is pushed down by the slope 26 against the urging force of the spring 24, and when the insertion is completed as shown in FIG. The state is such that the ridge 51 is prevented from falling out of the receiving groove 16. Since the locking claw 20 is provided at the back of the receiving groove 16, when the insertion ridge 51 pushes down the locking claw 20 as described above, the insertion ridge 51 has already entered the receiving groove 16 deeply, Since the straight advance of the insertion strip 51 by the stopper 18 and the engagement groove 52 is guided, the operator only has to concentrate on deepening the insertion, and the operation is easy. As described above, in the present invention, the first
The element 91 has an electrical length that is 1/4 times the wavelength of the low band of VHF due to the extension coil 83 for the low band of VHF, and 7/8 of the wavelength for the low band of UHF. On the other hand, from the second feeding point 55 through the second element 92 to the tip 91a of the first element 91, the second capacitor 86 is provided for the high band of VHF. As a result, the electrical length is 1/4 times the wavelength of the high band of VHF and 7/8 times the wavelength of UHF. In this case, there is a characteristic that any of the VHF low-band signal, the high-band signal, and the UHF signal resonates, and any of them can be received. In addition, in the case of the VHF high band reception, the wavelength is reduced to 1/4 times the wavelength by the electrical wavelength shortening effect of the second capacitor 86. Using the whole range longer than １ ／ of the wavelength, that is, from the second feed point 55 to the tip 91 a of the first element 91 via the second element 92, The advantage is that high gain can be obtained. In the case of UHF reception, since the extension coil 83 and the first capacitor 84 are provided at a quarter wavelength from the first feeding point 54 in the first element 91, The element 91 of 1 is 1/4 wavelength and 5/8 of UHF.
Acts as a two-stage antenna at the wavelength, while the second feed point
From 55 to the tip 91a of the first element 91 through the second element 92, the antenna operates as a 波長 wavelength antenna. There is a feature that gain can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a use state. 2A is a perspective view of an antenna main body, and FIG. 2B is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a side view showing a base and a lower part of an antenna main body. FIG. 4 is a perspective view showing a relationship between a base and a lower part of an antenna main body. FIG. 5 is a plan view of a base. FIG. 6 is a perspective view of a lower portion of the antenna main body. FIG. 7 is a sectional view taken along the line VII-VII in FIGS. FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 5; FIGS. 9A and 9B are cross-sectional views showing a process of inserting the insertion strip into the receiving groove. 10A is a cross-sectional view taken along line XX in FIG. 5, and FIG. 10B is a similar cross-sectional view showing a state in which a release operation button is pressed. FIG. 11 is a sectional view showing a structure of a connecting portion between an antenna base and an antenna tip. FIG. 12 is a perspective view of a connecting portion between an antenna base and an antenna tip. FIG. 13 is an exploded perspective view of a connecting portion between the antenna base and the antenna tip. FIG. 14 is a partially cutaway perspective view showing the structure of an element piece. FIG. 15 is a perspective view illustrating a configuration of a member that performs an electrical function as an antenna. FIG. 16 is a diagram showing an electrical configuration of an antenna. FIG. 17 is a side view showing a state where the antenna body is folded in two. FIG. 18 is a diagram showing a state in which the antenna main body is viewed from the direction of arrow XVIII in FIG. [Description of Signs] 54 First feeding point 55 Second feeding point 83 Extension coil 84 First capacitor 86 Second capacitor 91 First element 92 Second element

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01Q 1/32 H01Q 1/22 H01Q 5/01 H01Q 9/30

Claims (1)

(57) [Claim 1] It has a first feeding point and a second feeding point,
A first element having a length 7/8 times the wavelength of the UHF television signal is connected to the first feeding point, and the first element is connected to the first feeding point from the first feeding point. Wavelength 1
/ 4 times, the electrical length of the first element is VH
An extension coil is provided to make the wavelength of the low band television signal of F 1/4 times, and U
A first capacitor for passing an HF television signal is connected in parallel, while one end of a second element is connected to the second feeding point, and the other end of the second element is connected to a UHF television signal. Connected to an intermediate portion of the first element between the extension coil and the tip of the element via a second capacitor for passing, and from the second feeding point to the first element via the second element And the second capacitor is configured to have an electrical length from the second feeding point to the tip of the first element, which is 7/8 times the wavelength of the UHF television signal. Is 1/4 of the wavelength of the VHF high band TV signal.
A television antenna characterized in that the value is selected to be doubled.