JP4985597B2 - Patch antennas, lamps and traffic signal lamps - Google Patents

Description

  The present invention relates to a patch antenna, a lamp equipped with a patch antenna, and a traffic signal lamp equipped with a patch antenna.

In recent years, an Intelligent Transport System (ITS) has been proposed for the purpose of promoting traffic safety and preventing traffic accidents. In this ITS, a communication device (infrastructure device) is installed on the road, and the information emitted from the antenna of this communication device is received by the in-vehicle device of the vehicle traveling on the road, and this information is utilized, It is possible to improve the safety of traveling of the vehicle (see Patent Document 1).
When such road-to-vehicle communication is performed wirelessly, from the viewpoint of securing the prospect of wireless communication, an arm is extended from the column installed on the sidewalk or the like to the roadway side, and the antenna of the communication device is mounted on this arm. Further, when the line of sight can be secured without providing the arm, an antenna can be attached to the support column.

Japanese Patent No. 2806801

  In order to install the antenna of the communication apparatus on the road, it is not economical to provide a new support for the antenna, and it is not preferable from the viewpoint of the aesthetics of the road. In addition, since vehicle detectors, optical beacon heads, and the like are installed on the road, it is conceivable that an antenna is provided alongside a support post or arm to which these are attached. Absent.

  Therefore, the applicant of the present application has proposed an invention in which a patch antenna is stored in an optical unit of a lamp installed on a road so that a support for installing an antenna is not necessary and the aesthetic appearance of the road is not impaired. (For example, Japanese Patent Application No. 2007-186082 and Japanese Patent Application No. 2007-186019). Thus, in order to store the patch antenna in the optical unit, it is preferable to make the patch antenna compact.

  Then, it aims at providing the patch antenna which can be reduced in size, the lamp provided with this patch antenna, and the traffic signal lamp provided with this patch antenna.

The present invention is a patch antenna having a patch element and a ground element, and when the distance from the center to the end of the patch element is L, the feeding point of the patch element is L / L from the end. The patch element is a portion where a hole for inserting a power supply line is formed at the position of the power supply point, and the power supply line inserted through the hole is located at the center side of the position of 10. A through-hole that has a connection part that is a part to be soldered and penetrates the patch element at a position different from the hole through which the feeder line is inserted surrounds the connection part. It is characterized in that a plurality are formed in an arrangement .

  In the patch antenna, the voltage distribution in the patch element is 0 at the center of the patch element and is maximum at the end of the patch element. Also, the current is maximum at the center and close to 0 at the end. Therefore, the impedance (voltage / current) is 0 at the center and high impedance at the end. Thus, the impedance decreases as the center of the patch element is approached. Therefore, as in the present invention, since the feeding point of the patch element is located closer to the center than the position of L / 10 from the end of the patch element, impedance can be reduced and matched with this impedance. In addition, the distance between the patch element and the ground element can be reduced. As a result, the patch antenna can be made thin, and the antenna can be made compact.

Pas Tsu Ri solder Tsukegaa the switch element as a way of connecting the feed line, in the prior art, is the feeding point is usually to the end of the patch element, for this purpose, the feed line is at the edge of the patch element Connected by soldering. In this case, since the heat for connection is difficult to escape at the position of the end, it is easy to connect the power supply line.
On the other hand, according to the present invention, the feeding point is closer to the center side than the end of the patch element as described above, so that compared to the case where the feeding line is connected at the end as in the prior art, the solder It is conceivable that the heat at the time of attachment becomes easy to escape by conducting through the patch element, and it becomes difficult to connect the power supply line, but since the through hole is formed around the connecting portion, the heat is caused by this through hole. It becomes difficult to escape inside the patch element, and it becomes easier to connect the feeder.

  Further, when the use frequency band exceeds 1 GHz, the patch antenna can be made relatively compact. However, even if the patch element is set to a size that can be used in a frequency band of less than 1 GHz, as in the present invention. In addition, since the feeding point of the patch element is located closer to the center than the position of L / 10 from the end of the patch element, the distance between the patch element and the ground element can be reduced, and the patch antenna can be made compact. It becomes possible to do.

Moreover, it is preferable that the feeding point of the patch element is located closer to the end portion than the position of L / 1.7 from the end portion of the patch element.
If the feeding point is located closer to the center side than the position L / 1.7 from the end of the patch element, the band used for the patch antenna becomes narrow in order to ensure a predetermined antenna performance (for example, VSWR). However, in this case, it is possible to suppress the use band from being narrowed while ensuring the antenna performance.

In addition, the lamp of the present invention includes a light emitter, an optical unit having a visible light transmitting cover member that covers the light emitter forward, and a patch element in front of the optical unit. And the patch antenna stored later.
According to the lamp of the present invention, since the patch antenna can be configured to be thin in the front-rear direction, the patch antenna can be easily stored in the optical unit.

The optical unit of the lamp further includes a substrate on which the light emitter is mounted on a front surface, and the patch element and the ground element are disposed between the substrate and a front end of the light emitter. Preferably it is installed.
In this case, since the patch element and the ground element are installed between the optical unit substrate and the front end of the light emitter, the distance between the patch element and the ground element can be reduced as described above. In order to increase the distance to the front end of the light emitter, the length of the light emitter in the front-rear direction need not be particularly long. In addition, since the patch element and the ground element are installed in front of the board, it is possible to prevent the board from interfering with transmission / reception of radio waves by the patch antenna. Furthermore, since the patch element is installed at the same position in the front-rear direction as the front end of the light emitter or at the rear, the patch element does not hinder forward light emission by the light emitter.

Further, in this lamp, the patch element has a connection portion to which a power supply line is soldered at the position of the power supply point, and a through hole penetrating the patch element is formed around the connection portion. Preferably, the patch element and the ground element are installed between the substrate and the front end of the light emitter in a state where the light emitter is inserted through the through hole.
In this case, since a through-hole is formed around the connection portion, the heat at the time of soldering does not easily escape through the patch element by this through-hole, and the power supply line can be easily connected. The patch antenna is installed between the substrate and the front end of the light emitter by using the through hole that makes it easy to connect the power supply line, that is, by inserting the light emitter through the through hole. can do.

  The traffic signal lamp according to the present invention includes a light emitter that projects forward, an optical unit that has visible light transmission and a cover member that covers the light emitter forward, and a patch element in the optical unit. And the patch antenna in which the ground element is stored later.

  According to the traffic signal lamp of the present invention, since the patch antenna can be configured to be thin in the front-rear direction, the patch antenna can be easily stored in the optical unit. In addition, the light projecting direction of the optical unit and the directivity of the patch antenna stored in the optical unit can be matched forward. And since the traffic signal lamp is installed at a position where the line of sight is good with respect to the vehicle ahead, the patch antenna stored in the optical unit of this traffic signal lamp has the antenna directivity forward, for example, the vehicle It is possible to obtain a good communication state with the in-vehicle device mounted on the.

  According to the patch antenna of the present invention, the distance between the patch element and the ground element can be reduced, the patch antenna can be configured thinly, and the antenna can be made compact. For this reason, according to the lamp device and traffic signal lamp device of the present invention, the patch antenna can be easily stored in the optical unit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front view showing an embodiment of the lamp of the present invention. 1 is a traffic signal lamp 1 (hereinafter simply referred to as a signal lamp) installed on a road, and is for a vehicle. A support column 40 is installed on the side of a road such as a sidewalk, and an arm 41 is provided so as to protrude from the support column 40 to the roadway side, and the signal lamp 1 is attached to the arm 41.

  The signal lamp device 1 has a plurality (three in the illustrated example) of optical units 2 and a housing 3 in which the optical units 2 are incorporated. The three optical units 2 have red, yellow, and blue lamp colors, respectively. A eaves (not shown) is attached to each optical unit 2. A control device 5 that controls the signal lamp 1 is attached to the support column 40. The installation structure of the signal lamp 1 may be other than that shown in the figure. Although not shown, the form of the support column 40 and the arm 41 may be different, and the signal lamp apparatus 1 is installed on a pedestrian bridge. It may be. The control device 5 may be provided in the housing 3 of the signal lamp device 1.

  The control device 5 has a function of controlling lighting of the signal lamp 1, and the control device 5 can perform wireless communication control using an antenna 4 described later. Alternatively, the control device 5 that controls lighting and the like, and the control device for wireless communication using the antenna 4 may be separate. When these two control devices are separate, both control devices can be stored in the same casing 3. Or the control apparatus for radio | wireless communication can be installed in the vicinity (the same support | pillar 40) of the control apparatus 5 which controls lighting etc. of the signal lamp device 1. FIG.

  2, 3, and 4 are a perspective view, a front view, and a cross-sectional view of one optical unit 2. The optical unit 2 includes a light emitting diode 7 (hereinafter referred to as an LED 7) as a light emitter, an LED substrate 8 (hereinafter referred to as a substrate 8) on which a plurality of LEDs 7 are mounted on a front surface 8a, a housing member 6, and a cover member 9. have. In addition, the optical unit 2 of the present embodiment includes an antireflection member (light shielding member) 10 for preventing reflection of sunlight by the substrate 8 and the LED 7.

The substrate 8 is formed in a circular plate shape. A wiring pattern is formed on the back surface of the substrate 8, and this wiring pattern is connected to lead wires (terminals) 7 c and 7 d (see FIG. 4) of the LED 7. On the substrate 8, a plurality of LEDs 7 are arranged in a planar shape.
FIG. 5 is an enlarged cross-sectional view showing the LED 7 and its peripheral portion. The LED 7 includes a light emitting body 7f having an LED element 7b and a mold portion 7e, and two lead wires 7c and 7d extending rearward from the light emitting body 7f. The mold part 7e covers the LED element 7b. Moreover, the mold part 7e becomes a lens part. The front end of the mold part 7e is the front end 39 of the LED 7.

  In FIG. 4, the accommodating member 6 is formed of a steel plate, aluminum or a synthetic resin material, and has a bottom (bottom wall) 6a and a side (side wall) 6b erected from the periphery of the bottom 6a. The shape is open forward. A step portion 6c is formed on the inner periphery of the side portion 6b on the opening side, and a cover member 9 is detachably attached to the step portion 6c. A housing space S is formed between the housing member 6 and the cover member 9, and the LED 7 and the substrate 8 are housed in the housing space S. The substrate 8 is fixed to the housing member 6 via an antireflection member 10. Of the accommodation space S, the front space portion S1 is ahead of the substrate 8 and the back space portion S2 is behind the substrate 8.

  The cover member 9 is made of glass or resin and has visible light transparency (transparent to visible light), and covers the plurality of LEDs 7 at the front. In this optical unit 2, the front is the light projecting side (the cover member 9 side), and the rear is the bottom 6 a side of the housing member 6.

  The antireflection member 10 restricts the sunlight such as the western sun and the morning sun from entering the front surface 8a of the substrate 8 and the reflecting mirror 7a in the LED 7 (see FIG. 5), whereby the substrate 8 and the reflecting mirror 7a. It is possible to prevent the signal lamp 1 from being difficult to see due to reflection due to the occurrence of "pseudo lighting" which appears to be turned on when the signal lamp 1 is not lit. Further, the antireflection member 10 has a function as a support member that supports the substrate 8 and the antenna 4 described later.

The antireflection member 10 is formed in a plate shape from a synthetic resin material made of an insulating material (non-conductor), and is disposed in front of the substrate 8 so as to face the substrate 8 (with the antenna 4 in between). The antireflection member 10 includes a plate-like portion 10 a formed in a circular plate shape (plane shape), and this plate-like portion 10 a is provided behind the front end 39 of the LED 7. In the plate-like portion 10a, a plurality of insertion holes 10b for inserting the LEDs 7 are formed corresponding to the arrangement of the LEDs 7. The plate-like portion 10 a mainly prevents the sunlight from directly hitting the substrate 8. The antireflection member 10 is formed of a black synthetic resin material, or at least the front surface of the plate-like portion 10a is painted black so that the reflection of sunlight is prevented. The antireflection member 10 is fixed to the housing member 6 by fitting the outer peripheral portion of the plate-like portion 10 a to the stepped portion 6 c.
A boss portion 10c (see FIG. 4) is formed on the rear surface of the plate-like portion 10a so as to protrude rearward. The board | substrate 8 is being fixed to the plate-shaped part 10a with the screw | thread 25 screwed together by the screw hole of the boss | hub part 10c. An interval corresponding to the height of the boss portion 10 c is provided between the plate-like portion 10 a and the substrate 8.

  As shown in FIGS. 2 to 5, a flange 10 h is formed on the upper edge of the insertion hole 10 b of the antireflection member 10 so as to protrude forward. The eaves part 10h (see FIG. 5) prevents sunlight O shining from diagonally above such as the West or the Asahi from entering the reflecting mirror 7a of the LED 7. The front end of the collar portion 10 h protrudes from the front end 39 of the LED 7. The insertion hole 10b of the antireflection member 10 has a larger diameter than the mold part 7e of the LED 7, and the insertion hole 10b surrounds the outer peripheral surface of the mold part 7e and maintains the posture of the LED 7 erected forward from the substrate 8. It has a function to do. The antireflection member 10 may have only a function of preventing the reflection of sunlight by the substrate 8 or may have only a function of preventing the reflection of sunlight by the LED 7.

  As shown in FIGS. 2 to 5, an antenna is incorporated in the optical unit 2. The antenna is a patch antenna 4 and includes a patch element 11 and a ground element 12. The patch element 11 and the ground element 12 are accommodated in the accommodating space S, the ground element 12 is provided in front of the substrate 8, and the patch element 11 is provided in front of the ground element 12. Yes. Since the patch element 11 and the ground element 12 are provided behind the antireflection member 10, the antireflection member 10 can hide the patch element 11 and the ground element 12, and can be hidden from the front.

  The patch element 11 is formed in a planar shape (flat plate shape). The patch element 11 is attached to the plate-like portion 10a of the antireflection member 10 by a fastener including a bolt and a nut, not shown. In FIG. 4, the patch element 11 is provided on the rear side of the plate-like portion 10a. The patch element 11 is provided away from the substrate 8 forward, but is located behind the front end 39 of the LED 7.

  The ground element 12 is formed in a planar shape (flat plate shape), and is attached to the antireflection member 10 on the front surface 8 a side of the substrate 8. As shown in FIG. 4, a boss portion 10 f is formed on the rear surface of the antireflection member 10, and the ground element 12 is fixed to the boss portion 10 f with a screw 26. The ground element 12 is a position between the substrate 8 and the front end 39 of the LED 7 in the front-rear direction, and is provided behind the patch element 11. Thus, since the ground element 12 (and the patch element 11) is provided in front of the substrate 8, it is possible to prevent the substrate 8 from interfering with transmission / reception of radio waves by the patch antenna 4.

The patch element 11 and the ground element 12 can be formed from a metal plate. As the material of the patch element 11 and the ground element 12, a material having conductivity and high conductivity is preferable. For example, copper, a copper alloy such as brass, aluminum is preferable, and iron, nickel, or other metal may be used. it can. In addition, since a high-frequency current flows on the surface, a plate member made of a non-conductor such as a resin may be subjected to metal vapor deposition or metal plating (gold or silver plating) (see FIG. Not shown). Further, the shape of the patch element 11 and the ground element 12 can be arbitrary, and can be rectangular or circular.
Further, a dielectric (dielectric member) having a relative dielectric constant larger than that of air may be interposed between the ground element 12 and the patch element 11, but in the illustrated form, the dielectric is omitted. Air.

  Since the patch element 11 and the LED 7 overlap each other in the front-rear direction, the patch element 11 is formed with a through hole 34 (see FIG. 5) as an opening through which the LED 7 is inserted. Similarly, since the ground element 12 and the LED 7 overlap with each other in the front-rear direction, a through hole 14 is formed in the ground element 12 as an opening through which the LED 7 (lead wires 7c, 7d) is inserted. The through holes 14 and 34 are holes that penetrate the patch element 11 and the ground element 12, and the arrangement of the through holes 14 and 34 matches the arrangement of the LEDs 7, and the patch element 11 and the ground element 12 are It has a mesh structure. By inserting the LED 7 into the through hole 34 and the through hole 14, the patch element 11 and the ground element 12 are installed at predetermined positions without interfering with the LED 7.

4, a terminal portion 19 for connecting a coaxial cable 15 for the antenna 4 is attached to the housing member 6 (bottom portion 6a). The coaxial cable extending from the control device 5 side in FIG. 15 can be connected. A coaxial cable 15 a extending from the terminal portion 19 to the rear space portion S <b> 2 is connected to the patch antenna 4.
In FIG. 5, the coaxial cable 15a has an inner conductor 15b, an insulator 15c, an outer conductor 15d, and a covering portion 15e. The inner conductor 15b is connected to the patch element 11 by soldering, and the outer conductor 15d It is connected to the ground element 12 by soldering. The coaxial cable 15a supplies power to the antenna 4.
Further, a power cable (not shown) for the LED 7 extending from the control device 5 side of FIG. 1 is connected to the substrate 8 via a terminal portion (not shown) attached to the bottom 6 a of the housing member 6. .

  FIG. 6 is an explanatory diagram for explaining the feeding point P of the patch antenna 4. In FIG. 6, the center of the patch element 11 is C and the end is E. Since the patch element 11 is rectangular, the intersection of the diagonal lines is the center C. When the patch element 11 is circular, the center of the circle is the center C of the patch element 11. The end E is an intersection of a straight line connecting the feeding point P from the center C and an end edge (one side) of the patch element 11. Further, the distance from the center C to the end E of the patch element 11 is L.

  The patch element 11 has a connection portion 13 for connecting the inner conductor 15b (see FIG. 5) of the coaxial cable 15a. The connection portion 13 is a portion of the patch element 11 where a hole for inserting the inner conductor 15b is formed, and a portion to which the inner conductor 15b is soldered (a portion to be connected by heating). That is, the connecting portion 13 is provided at a position where the feeding point P is set, and the position of the connected inner conductor 15 b matches the feeding point P.

  In the patch antenna 4, the element length (2L in FIG. 6) of the patch element 11 is ½ wavelength, so that the voltage distribution in the patch element 11 is 0 at the center C and the maximum at the end E. . Further, the current becomes maximum at the center C and becomes close to 0 at the end E. Therefore, the impedance (voltage / current) is 0 at the center C and high impedance at the end E. Thus, the impedance decreases as the center C of the patch element 11 is approached (see FIG. 7). FIG. 7 is an explanatory diagram for explaining the distribution of impedance. If the feeding point P is too close to the center C, the function as an antenna is lowered, and if the impedance is 0, radio waves cannot be radiated.

  Therefore, in FIG. 6, in the patch antenna 4 of the present invention, the feeding point P of the patch element 11 is located closer to the center C side than the position L / 10 from the end E. Thus, by positioning the feeding point P of the patch element 11 closer to the center C side than the end E, the impedance is reduced, and in order to match this impedance, the patch element 11 and the ground element 12 The distance in the front-rear direction (between elements d in FIG. 5) can be reduced. As a result, the patch antenna 4 can be made thin in the front-rear direction, and the patch antenna 4 can be made compact.

  In particular, as shown in FIG. 5, a patch element 11 is stored in front of the optical unit 2 and a ground element 12 is stored after the patch element 11 in the optical unit 2. Although the patch element 11 and the ground element 12 are installed between the front end 39 and the front-rear direction, as described above, the patch antenna 4 can be configured to be thin in the front-rear direction, so that the patch antenna 4 is stored in the optical unit 2. It's easy to do.

  Furthermore, since the patch antenna 4 is configured to be thin in the front-rear direction in order to install the patch element 11 and the ground element 12 between the front-rear direction between the substrate 8 and the front end 39 of the LED 7, the front end of the LED 7 from the substrate 8 is configured to be thin. The length A in the front-rear direction of the LEDs 7 up to 39 does not have to be particularly long. Therefore, in the optical unit 2 in which the LED 7 which is a general-purpose product is employed, the patch element 11 is positioned behind the front end 39 of the LED 7 and the ground element 12 is positioned forward of the substrate. The patch antenna 4 can be easily stored.

  Here, the feeding point of the conventional patch antenna will be described. Conventionally, the feeding point is the end of the patch element. As shown in FIG. 7, as the position of the feeding point is slightly different from the end E of the patch element toward the center C, the impedance variation increases (that is, the gradient of the graph of FIG. 7 becomes larger). Therefore, when the feeder line is connected closer to the center C of the patch element than the end E, if the connection position has an error, the antenna characteristics will change greatly. Therefore, conventionally, the end of the patch element is used as a feeding point so as not to affect the characteristics of the antenna even if an error occurs in the connection position (to ensure the quality of the antenna).

  Furthermore, when the feed point is the end of the patch element as in the conventional case, there is an advantage that the feed line (coaxial cable) can be easily connected to the patch element. That is, as a method of connecting the power supply line to the patch element, there is soldering. When the power supply line is connected by soldering at the end in order to set the power supply point to the end of the patch element, soldering is performed at the position of the end. The attached heat is difficult to escape, so it is easy to connect the feeder.

  On the other hand, according to the present invention, the feeding point P is brought closer to the center C of the patch element 11 as described above, so that the coaxial cable 15a is compared with the case where the feeding point is the end E as in the prior art. The heat at the time of connecting the inner conductor 15b is likely to escape through the patch element 11 and it is difficult to connect the coaxial cable 15. However, as shown in FIG. Since a plurality of through holes 34 for inserting the LEDs 7 are formed around the connecting portion 13 to be connected, the through holes 34 make it difficult for soldering heat to escape inside the patch element 11, and the inner conductor 15 b It becomes easy to connect.

  If a specific example is demonstrated about the magnitude | size and position of the through-hole 34, the diameter of the through-hole 34 can be 8-12 mm (10 mm in embodiment), and if it is this diameter, LED7 of the signal lamp device 1 will be inserted. Can do. A plurality of through holes 34 are formed around the feed point P so that the distance from the feed point P to the edge of the through hole 34 is 10 to 20 mm (15 mm in the embodiment). That is, the through hole 34 is provided in the vicinity of the feeding point P. The through-hole 34 can suppress the heat at the time of soldering from being transmitted to the periphery of the connection portion 13 through the patch element 11 and escaping, thereby enabling efficient soldering.

  With the above configuration, the patch element 11 and the ground element 12 are provided in the front space S1 in the optical unit 2 and in the range A from the front surface 8a of the substrate 8 to the front end 39 of the LED 7 ( (See FIG. 5). Then, the patch element 11 and the ground element 12 are arranged to face each other in the front-rear direction, and the directivity of the antenna 4 is the direction toward the front. Thereby, the light projecting direction by the optical unit 2 and the directivity of the patch antenna 4 substantially coincide. Further, since the signal lamp 1 is installed at a position where the line of sight is good with respect to the vehicle, a good communication state can be obtained with the vehicle-mounted device (not shown) of the vehicle by the antenna directivity.

  Furthermore, since the front end 39 of the LED 7 is positioned in front of the patch element 11, it is possible to prevent the patch element 11 from hindering forward light emission (lamp light) by the LED 7. Further, since the ground element 12 and the patch element 11 are provided in front of the substrate 8, it is possible to prevent the substrate 8 from hindering transmission / reception of radio waves by the patch antenna 4.

  In addition, in order to use the signal lamp 1 storing the patch antenna 4 for an intelligent road traffic system (ITS) that performs wireless communication between road vehicles, the use frequency band of the patch antenna 4 is set to less than 1 GHz, Specifically, it is set to a 700 MHz band frequency (715 MHz to 725 MHz). A specific example of the patch antenna 4 for use in this frequency band will be described.

  FIG. 8 is a result of a simulation for determining the relationship between the position X of the feeding point P of the patch antenna 4 stored in the optical unit 2 shown in FIG. 6, the inter-element d (see FIG. 5), and the antenna characteristics. It is the table | surface which shows. In all of Examples 1 to 7 and the conventional example in which the position X of the feeding point P is different, the patch element 11 is square (rectangular), and the length (2L) of one side is about 170 mm. FIG. 9 is a graph showing the relationship between the position X of the feeding point P and the element spacing d, and FIG. 10 shows the relationship between the position X of the feeding point P and the bandwidth where VSWR <1.5. It is a graph.

  In the conventional example, the position X of the feeding point P is 1 mm from the end E (X = L / 85). In this case, the inter-element d is 25.0 mm, whereas in Example 1, the feeding point is The position X of P is 10 mm from the end E (X = L / 8.5), and in this case, the distance d between the elements is 24.5 mm. FIG. 9 shows that the position X of the feeding point P in Example 1 is 10 mm from the end E and is located closer to the center C than the position L / 10 (that is, X> L / 10). As shown, the effect of shortening the inter-element d is started. That is, in FIG. 9, by setting the feeding point P to the center C side from the position E / 10 from the end E, the rate of change (gradient of the graph) for shortening the inter-element d increases.

  In particular, in the signal lamp 1, the patch antenna 4 is stored in the optical unit 2 having the LED 7 that is widely used (having a normal length), and the front-rear direction between the front end 39 of the LED 7 and the substrate 8 is stored. In order to install the patch element 11 and the ground element 12 between the two, a patch in which the feeding point P is located closer to the center C side than the position L / 3 from the end E (X> L / 3) The antenna 4 is preferable. That is, as in Example 3 of FIG. 8, by setting the position X of the feeding point P to 30 mm (X = 1 / 2.8), the inter-element d can be set to 20 mm, which is 5 mm than the conventional example. Can be shortened.

  Further, as in the seventh embodiment, by setting the position X of the feeding point P to a position 55 mm from the end E (by separating the feeding point P from the end E greatly), the inter-element d is reduced to 10 mm. Can do. However, in this case, in order to secure the antenna characteristic of VSWR <1.5, the use band is narrowed to 8 MHz. For this reason, from the viewpoint of securing the antenna characteristics (VSWR <1.5), the feeding point P is located closer to the end E side than the position L / 1.7 from the end E of the patch element 11. Is preferable (that is, X <L / 1.7).

  That is, as shown in FIG. 10, when the feeding point P is located in the range of the center C side from the position E / L from the end E, that is, the center C side from X = 50 mm. If the feeding point P is located at a position where the patch antenna 4 is used in order to secure the antenna performance VSWR <1.5, the band used for the patch antenna 4 becomes narrower, but is located closer to the end E than the position. Thus, it is possible to suppress the use band from becoming narrow (for example, less than 10 MHz) while ensuring the antenna performance VSWR <1.5. Particularly preferable from the viewpoint of antenna performance is a case where the feeding point P is located in a range closer to the end E than the position E / 2 from the end E (that is, X <L / 2). .

  From the above, from the viewpoint of shortening the inter-element d and securing the antenna characteristics (VSWR <1.5), the feeding point P is located on the center C side from the position L / 3 from the end E. And it is preferable that it is located in the edge E side rather than the position of L / 1.7 from the edge E. More preferably, the feeding point P is located closer to the center C than the position L / 3 from the end E, and is located closer to the end E than the position E / 2 from the end E. It is a case.

Since the patch element 11 and the ground element 12 are used at a 700 MHz band frequency, the inter-element d becomes large in the conventional example (described with reference to FIG. 5). For this reason, the patch element 11 is located largely in front of the substrate 8, and the patch element 11 may be in front of the LED 7, thereby hindering light projecting properties. In order to eliminate this, in order to increase the distance from the substrate 8 to the front end 39 of the LED 7, it is conceivable to employ the LED 7 having a particularly long length in the front-rear direction (for example, the lead wires 7c and 7d are lengthened). ).
However, according to the present invention, since the inter-element d between the ground element 12 and the patch element 11 can be reduced, the ground element 12 is provided immediately in front of the substrate 8 and further smaller in front of this. If the patch element 11 is provided between the possible elements d, the front end 39 of the LED 7 can be located at the same position or in front of the patch element 11, and the LED 7 does not need to be particularly long as described above.

  According to the signal lamp 1 of the above embodiment, since the patch antenna 4 is stored in the optical unit 2, the patch antenna 4 can be installed in the signal lamp 1 without making it conspicuous, and the aesthetics of the road can be improved. There is no loss. And since the antenna 4 is stored in the optical unit 2, a dedicated support | pillar for antenna installation can be made unnecessary.

Further, since the patch antenna 4 is not in an exposed state (a state protruding from the lamp housing), in the design of the support column 40 and the arm 41 (FIG. 1) for mounting the signal lamp 1, the wind load received by the antenna 4 is not affected. There is no need for additional consideration. Further, there is no need to additionally consider rust prevention and dust prevention for the antenna 4.
Further, since the traffic signal lamp 1 is installed on the road in consideration of the visibility by the driver of the vehicle, the patch antenna 4 and the signal antenna 1 of the embodiment are installed at a predetermined position on the road. When wireless communication is performed with an in-vehicle device of a vehicle, a state with a good view is naturally obtained. Thereby, the patch antenna 4 incorporated in the optical unit 2 of the signal lamp device 1 can be used for an intelligent road traffic system (ITS) that performs wireless communication between road vehicles, and a good communication state is obtained.

The ground element 12 and the patch element 11 may be arranged in parallel, but one or both of the patch element 11 and the ground element 12 are inclined with respect to the substrate 8 in order to adjust the antenna directivity. It may be arranged.
Note that the signal lamp 1 is normally installed with the board 8 itself inclined slightly downward in view of visibility to the driver. Therefore, by attaching the patch element 11 and the ground element 12 in parallel to the substrate 8, the directivity of the antenna 4 is also directed downward, but the radio communication area between road vehicles is limited or the reliability is increased. For the purpose, the substrate 8 may be tilted further downward.

Moreover, the lamp (traffic signal lamp) of the present invention is not limited to the above embodiment. In each of the above embodiments, the patch element 11 has been described as being behind the antireflection member 10, but the patch element 11 may be in front of the antireflection member 10 as illustrated in FIG. 11. Even in this case, the feeding point E of the patch element 11 is located closer to the center than the position L / 10 from the end E. When the patch element 11 is provided on the front surface of the antireflection member 10, the patch element 11 can be attached to the front surface or attached with a set screw.
In this case, the patch element 11 is preferably coated in the same color as the antireflection member 10. Thereby, the patch element 11 becomes inconspicuous. Furthermore, the front surface of the antireflection member 10 is subjected to surface treatment with fine irregularities such as satin treatment in order to diffusely reflect sunlight (in order not to reflect sunlight in a certain direction like a mirror). . Therefore, it is preferable to apply the same surface treatment (treatment with the same roughness) to the patch element 11, thereby making the patch element 11 more inconspicuous.

  The traffic signal lamp may be for pedestrians as well as for vehicles. Moreover, the light-emitting body which a traffic signal lamp has may be a light bulb other than LED. The lamp of the present invention may be an illuminating lamp for road illumination in addition to a traffic signal lamp. In this case, there are mercury lamps and sodium lamps as light emitters.

It is a front view which shows one Embodiment of the lamp device of this invention. It is a perspective view of an optical unit. It is a front view of an optical unit. It is sectional drawing of an optical unit. It is an expanded sectional view which shows LED and its peripheral part. It is explanatory drawing explaining the feeding point of a patch antenna. It is explanatory drawing explaining distribution of impedance. It is a table | surface which shows the result of having calculated | required the relationship of the position of the feeding point of a patch antenna, between elements, and an antenna characteristic by simulation. It is a graph which shows the relationship between the position of the feeding point by simulation, and between elements. It is a graph showing the relationship between the position of the feeding point by simulation, and the bandwidth where VSWR <1.5. It is sectional drawing of the optical unit which the lamp of other embodiment has.

Explanation of symbols

1 Traffic signal lamp (lamp)
2 Optical unit 4 Patch antenna 7 LED (light emitter)
8 Substrate 9 Cover member 11 Patch element 12 Ground element 13 Connection portion 15a Coaxial cable (feed line)
34 Through-hole 39 Front end C Center E End L Distance P Feed point

Claims (7)

In a patch antenna having a patch element and a ground element,
When the distance from the center of the patch element to the end is L, the feeding point of the patch element is located closer to the center than the position of L / 10 from the end ,
The patch element has a connection part which is a part where a hole for inserting a power supply line is formed at a position of the power supply point and a part where the power supply line inserted through the hole is soldered,
Around the connection portion, a plurality of through holes penetrating the patch element at positions different from the hole through which the feed line is inserted are formed so as to surround the connection portion. Patch antenna. The patch antenna according to claim 1 , wherein the patch element is set to a size used in a frequency band of less than 1 GHz. 3. The patch antenna according to claim 1, wherein a feeding point of the patch element is located closer to the end portion than a position of L / 1.7 from the end portion of the patch element. An illuminant, and an optical unit having a visible light transmission and a cover member covering the illuminant at the front;
The patch antenna according to any one of claims 1 to 3 , wherein a patch element is stored in the optical unit before and a ground element is stored behind. . The optical unit further includes a substrate on which the light emitter is mounted on the front surface,
The lamp device according to claim 4 , wherein the patch element and the ground element are installed between the substrate and a front end of the light emitter. In the state of being inserted through said light emitter before SL through hole lamp according to between the front and rear direction between the front end of the substrate and the light emitter, to claim 5 wherein said patch element and said ground element is provided vessel. A light emitter that projects forward, and an optical unit that has visible light transmission and a cover member that covers the light emitter forward,
The traffic signal lamp comprising: the patch antenna according to any one of claims 1 to 3 , wherein the patch unit is stored in the optical unit and the ground element is stored in the rear. vessel.

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